Category Archives: habitat at home

habitat at home

Growing perennial wildflowers from seed

Pink echinacea, and pale purple wild bergamot flowers in a raised bed
Perennial wildflowers add both beauty and food for beneficial insects to your yard.

Why grow perennial wildflowers?

Native wildflowers feed and shelter beneficial insects that pollinate our plants and help us control pests. Beneficial insects include a diverse collection of pollinators — not just honey bees — as well as natural enemies (flies, wasps, beetles, bugs and other insects that kill pests). While not technically insects, spiders and predatory mites also serve as natural enemies of pests. Cooperating with insect natural enemies for pest control helps us reduce damage from pests while reducing risks to the environment and people from other pest management strategies like pesticides.

The pollen and nectar produced by these native flowers – and many non-native flowers – either directly feed these friendly insects, or feed other insects that are prey for natural enemies. The leaves and stems also provide shelter for beneficial insects year-round. While we’re focusing on flowers today, many grasses also provide this shelter. Beyond all the ecological benefits, native wildflowers are beautiful!

Preparing perennial seeds to germinate

Seeds with spikey tails held in the palm of a white woman’s hand
Growing perennial flowers from seed does take longer, but it can be fun and rewarding!

In this part of the world (now known as upstate New York), seeds from native perennial wildflowers that mature in summer and fall experience a lot of “weathering” between maturation and germination the following spring. This includes cycles of freezing and thawing temperatures as well as varying levels of moisture during the winter. They may even pass through the digestive system of animals. This is why planting perennial wildflower seed in the fall is a great option. You are allowing nature to do the work of preparing the seeds for germination in the spring. If you harvest seeds of native perennial wildflowers and want to start them in the spring with other seeds, you will need to do this work yourself.

Some seeds have very hard seed coats that need to be broken by physical force (for example scratching with sandpaper, a file, or a knife), heat (for example, submerging in boiling water), cold (for example, freezing), or chemicals (like a strong acid). This is called seed scarification. Seeds that require scarification – and those that don’t – may also require stratification, which signals to the seeds that they can “wake up” (called breaking dormancy) and start germinating. Seed stratification generally requires exposing the seeds to the right level of moisture and the right temperature for the right length of time. Some examples include:

  • Hot water soak – Pour hot water over seeds and allow them to soak overnight or for 24 hours
  • Cold moist stratification – Mix seeds with sterile sand, vermiculite, or another substance that won’t hold too much moisture. You could also place seeds between layers of a damp paper towel or coffee filter. Make sure that whatever medium you use is only damp and not too wet. Put the mixture in a plastic bag or closed container in your refrigerator for the required amount of time.

If you buy perennial wildflower seeds, they may have already been stratified. Follow the instructions that come with your seed or reach out to the seller for more information.

Light brown seeds sitting on top of damp potting mix in a plastic container
One way to stratify seeds (prepare them for germination) is to place them in moist potting mix in the refrigerator for several weeks to several months.

Species-specific instructions

Examples of perennial wildflower seeds that benefit from scarification and/or stratification follow. After these seeds are scarified and/or stratified, germination may be improved by putting them in a warm place (but not for all species). Remember that you can always sprinkle seeds on well-prepared, weed-free soil outside in the fall and let the winter do the work for you! Also, your experience germinating these seeds may differ from the recommendations below. There is so much beautiful diversity in these perennial wildflowers!

  • Blue false indigo (Baptisia australis) – First scarify the seeds. Gently rub them between medium-grit sandpaper to scratch the seed coat. Then use the cold moist stratification method, leaving them in the refrigerator for about 10 days.
  • New York Ironweed (Vernonia noveboracensis) – Use cold moist stratification, keeping seeds chilled for 60 days.
  • Asters (Symphyotrichum spp.) – If you look up how to seed asters, you’ll see different instructions for different species, including seeding them in the spring without stratification and using a 60-day cold stratification period. Amara tried germinating Symphyotrichum oblongifolium (aromatic aster) seed and had better luck with cold moist stratification than seeding without stratification. You might see different results with different species.
  • Milkweed (Asclepias spp.) – Store (well-dried!) seeds in the freezer for several months (e.g., from the time you harvest them in the fall, until you are ready to start them in the spring). Learn more from Petra at Fruition Seeds.
  • Coreopsis (Coreopsis spp.) – Note that some coreopsis species are annuals in upstate NY. Perennial species will likely germinate best with cold moist stratification (30-60 days, depending on species).
  • Echinacea (Echinacea purpurea) – These seeds will likely germinate just fine if you plant them in moist soil and provide warmth (e.g., a heat mat) just as you would annual seeds.
  • Blazing star (Liatris spicata) – Moist stratify for 60 days before planting seeds.
  • Beard tongue (Penstemon spp.) – Cold stratify for 30-60 days before planting seeds. Some species may require light for germination. Cover seed of these species with only a very thin layer of potting mix (if any) and provide light when germinating.
  • Mountain mints (Pycnanthemum spp.) – You should be able to germinate seeds without stratification, but they will likely germinate better with light. Cover seed with only a very thin layer of potting mix (if any) and provide light when germinating.
  • Rudbeckia (Rudbeckia spp.) – Different species of Rudbeckia may require different stratification (or none) for seed to germinate. For many species, cold moist stratification for at least 30 days is recommended.
  • Goldenrod (Solidago spp.) – There are many species. Most will likely germinate best if seed is moist stratified for 60 days, and then receive light after seeding. Cover seed with only a very thin layer of potting mix (if any) and provide light when germinating.
  • Spiderwort (Tradescantia ohiensis) – For this species, you are better off direct-seeding in the fall. The recommended cold moist stratification period is 120 days, and these seeds will germinate better in cool soil.
  • Golden alexanders (Zizia aurea) – You may have better luck sowing these seeds outside in the fall than trying to start them inside in the spring. Their leaves are fairly distinctive (like celery) so seedlings are easier to spot outdoors. If you do want to try starting them indoors, use a 60-day cold moist stratification.

For some of the species that require longer stratification, you may be worried that you’re running out of time this spring. Remember that even after you have prepared your seeds to germinate, they will likely need around 6 weeks to germinate and grow big enough to consider transplanting outdoors. Don’t despair! Fall is a great time to transplant perennial wildflowers. And perhaps your heat mats and grow lights (or other seed germination spot) are otherwise occupied starting annual vegetable and herb transplants this spring. If you start stratifying seeds in early May, even those that require 60 days in the fridge will be ready for germination in early July. Then your seedlings will have plenty of time to grow big and strong before fall transplanting. Just be sure to keep them watered.

 

Resources consulted on seed germination:

 

This post was written by Amara Dunn-Silver, Biocontrol Specialist and Elizabeth Lamb, Ornamentals IPM Coordinator with the NYSIPM Program.

This work is supported by NYS Departments of Environmental Conservation and Agriculture and Markets.

habitat at home

Fall is for planting…these resources can help!

A mixture of plant seedlings in plots and trays sitting on a gravel surface
Cooler days and more moisture make fall a less-stressful time for transplanting perennials.

You’ve probably heard that fall is the best time to plant perennials (including seed for perennial wildflowers). Are you planning to start or expand a planting that supports pollinators and natural enemies of pests (beneficial insects) this fall? Trying to decide what to plant? I wanted to make sure you know about some resources from NYSIPM (some of them new this summer) that can help!

Who are you trying to attract?

Red lady beetle with black spots perched on a goldenrod plant
Some lady beetle species weed on pollen, in addition to aphids and other insects.

The good news is that flowers that produce lots of pollen and nectar and provide season-long blooms (usually as part of a mixed planting) will support a diverse group of both natural enemies that eat pests and pollinators. If you want to get a bit more specific than that, you might consider checking out:

  • Natural Enemies and What They Eat in the Field – Targeting a particular pest? This chart can help you determine which natural enemies will help.
  • (New!) Pocket Guide to Beneficial Insects – This guide was created for urban growers in New York City, but fortunately all of the beneficial insects in the Guide can be found throughout NY. It will help you recognize beneficial insects when you see them.

These resources are linked from this page. The NYSIPM website is in the process of migrating, and I’ll update this link once this page moves. You can also read about “friends in the garden” (natural enemies) that you’ll find on the ground and on plants or flying through the air in previous blog posts.

Picking plants

A raised bed containing a variety of different plants (with red, purple, yellow, or pink flowers) and labels naming each plant
Choosing a mixture of flowering plants can provide season-long blooms for beneficial insects.
  • Plants for Natural Enemies (full list) – A very large spreadsheet summarizing data from university research and extension resources; Everything I could find about individual plant species and which insects (especially natural enemies) they support.
  • (New!) Plants for Natural Enemies (2 pg handout) – Much shorter table listing 26 plants (perennials and annuals) that will support natural enemies (and pollinators); Bloom times are for central NY, and may vary in other locations (especially different USDA plant hardiness zones).

These resources are also linked from this page. And I’ve written a few blog posts about choosing plants (here and here).

 

What are you planting this fall?

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program.

Community IPM, habitat at home, Uncategorized

Permission to procrastinate on some fall yard work

Several maple leaves colored red, orange, yellow, and green laying on sidewalk pavement
Fall leaves are beautiful…but fall garden clean-up isn’t always fun. Maybe skip some of that clean-up this year.

If you have been procrastinating on your fall garden clean-up (like me), I’ve got good news for you! You may want to just erase some of those tasks from your to-do list altogether. And you can do it guilt-free!

As you may recall from my post this spring, a messy garden provides good shelter for friendly insects like pollinators and natural enemies of pests over the winter. Whether it’s leaves on the ground or dead plant stems, it’s not a bad idea to leave at least some debris in your yard and garden. The Xerces Society provides a nice summary of the benefits fallen leaves offer to insects and other creatures. You can read an eloquent description of all the benefits of a messy yard here.

Some pink zinnia flowers growing near stems of perennials that are brown with dry seed heads
As these plants continue to senesce, I will leave the stems in the garden over the winter.

Just to prove I’m putting my money where my mouth is, here are some pictures from my own yard. I’m thinking about cutting down the sunflower stalks and propping them up next to my compost bin in the back yard, just to make things a little tidier in the front yard.

some pink, yellow and orange flowers still blooming among dying plant stems
These sunflowers, cosmos, and zinnia plants are no longer looking so nice. But I will leave many of them in the garden until spring.

I’m going to still take out (and send to my local municipal compost facility) my vegetable plants (tomatoes and peppers). Leaving dead stems from healthy plants in your garden is one thing, but this year’s vegetable plants can harbor next year’s vegetable diseases and insect pests if left over the winter. Disposing of diseased or insect-infested plants away from your garden is just good IPM.

A few more caveats…

First, you should know that ticks complicate the simple advice to “leave the leaves”. If you’ve had problems with ticks in your yard (learn how to monitor for ticks here), be strategic about where you leave things messy, and where you clean them up. For example, consider cleaning up areas where your family and pets spend more time. You should also be careful about where you pile leaves. My co-worker Joellen explains why here. And definitely use other IPM strategies to protect yourself from ticks, regardless of your yard clean-up plans.

Small pile of leaves and dead plant stems next to a white fence
This was the leaf (and other plant debris) pile in my backyard this spring. Piles like this can shelter lots of invertebrates…including ticks.

Second, if you’ve got a garden bed in the front yard that you just can’t stand to leave messy through the winter, it’s ok to clean it up and not feel guilty. Maybe pick another part of your yard that you can leave a bit messy instead. Don’t let the perfect become the enemy of the good.

Happy Fall!

Maple tree with orange and yellow leaves against a bright blue sky

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

This work is supported by:

  • New York State Department of Agriculture and Markets
  • New York State Department of Environmental Conservation
agriculture, habitat at home, home gardens, ornamentals, vegetables

Know your friends…on the ground

Small clump of blue-green grass surrounded by some bare ground and weeds
We may not spend a lot of time looking at the ground, but there are plenty of friendly insects living at the soil surface and taking shelter in plants like this little bluestem grass that don’t produce pollen-rich flowers, but still support beneficial insects.

In August I wrote about some of the friendly insects that might be visiting your garden this summer. I promised to write more about the natural enemies of pests that you might find at ground level. That time has come! Because these insects (and some other arthropods) live at or near the soil surface, you’re much less likely to see them, unless you happen to be cleaning out a garden bed this fall (which is not actually recommended). Also, they may be more active at night. But they are still doing lots of good things in your garden or on your farm, so they’re worth knowing about.

Rove beetles

Black beetle with a long segmented abdomen that protrudes beyond the short wing covers that look like a cape.
Rove beetles have wing covers that are much shorter than the rest of their body. Image courtesy of Joseph Berger, Bugwood.org.

These beetles live in the soil or at the soil surface and they eat lots of different soil invertebrates, including pests like slugs, snails, thrips, and eggs of other insects. They also eat seeds, so they could help reduce your weed seed bank, too. Like other beetles, they have hard covers over their wings called elytra. Because these covers are much shorter than their bodies, I think it makes them look like they are wearing little capes.

 

Carabid beetles

Black beetle crawling on the ground
Ground beetles may not look very exciting, but they’re great predators to have in fields and yards. Image courtesy of Mary C Legg, Bugwood.org.

Also called ground beetles, this large group of insects mostly live on the ground, and tend to have prominent jaws and move very fast. Their speed makes them great predators of many insects, as well as snails and slugs. Depending on the species, they may also eat seeds. They like to spend the winter in sheltered places including perennial grasses that grow in clumps. In the spring, they can travel almost 200 feet from these grassy shelters (Landis et al. 2000. Annual Review of Entomology 45:175-201). They come in different sizes, but tend to be darker colored.

On the left a black ground beetle with large jaws, and on the right a ground beetle with large jaws that is brown on top of its body and iridescent green on the underside of its body
Just a few more examples of ground beetles, because they’re so cool!

Centipedes

brown centipede with one pair of legs per body segment
Centipedes may not be so pretty to look at, but they’re good predators to have around. Image courtesy of Joseph Berger, Bugwood.org.

They may not look as friendly as lady beetles, but centipedes are also generalist predators that eat lots of invertebrates (including pests) in the soil. In case you were wondering, the difference between a centipede and a millipede is that centipedes have only two legs (one pair) on each segment of their body, while millipedes have four legs (two pairs) per body segment. But they can move pretty quickly, so it’s understandable if you don’t have time to count.

Spiders and harvestmen

From left to right – black and yellow spider, cream-colored spider on a red flower eating a bee, brown daddy long legs on green foliage.
These are just a few of the eight-legged friends you might find in your garden or fields. Some species you’re more likely to find on plants, and others spend more time on the ground.

I wrote about spiders in my previous post, but many species live on or near the ground. Both are good predators, and friends you’d like to have in your fields or garden. Technically, harvestmen (also called daddy long legs) are not spiders, but they do have eight legs. Because they don’t have an obvious “waist” they appear as though their head and body are a single “blob”.

Fireflies

Adult firefly, mostly black with some orange markings
Adult fireflies are more easily recognizable, even when they aren’t lit up. Image courtesy of Whitney Cranshaw, Colorado State University, Bugwood.org.

Yes, you read that correctly. When they are immature, fireflies (or lightening bugs, depending on where you grew up) look a bit more like worms than beetles (which is what they actually are). They live on the ground (especially in places with more moisture) and feed on invertebrates with soft bodies, including both snails and insects. Although we tend to notice them when they are flying, adult fireflies (depending on the species) also spend plenty of time on the ground, and may or may not be predators. The Xerces Society has some really good information about fireflies and their conservation.

immature firefly with distinct body segments. Looks sort of like an armored worm, but with six legs
Immature fireflies may not be so familiar, but are good “friends” because they eat soft-bodied invertebrates, including pests. Image courtesy of Gerald J. Lenhard, Louisiana State University, Bugwood.org.

So remember, not everything that creeps or crawls through your fields or garden is a problem. There are lots of friendly insects (and other arthropods) that can help you with pest control. Take a closer look and you might be surprised!

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

This work is supported by:

  • New York State Department of Agriculture and Markets
  • New York State Department of Environmental Conservation
  • The Towards Sustainability Foundation
agriculture, Community IPM, habitat at home, home gardens

Know your friends

Pink zinnias and yellow cosmos growing next to the brick wall of a house
Zinnias and cosmos are great food sources for all kinds of insects.

As we start August in New York, I hope that your gardens and fields are full of abundant blooms, vegetables, fruits, or all of the above. They may also be humming, buzzing, or making other noises as a result of resident insects. If you find an unfamiliar insect, you might be wondering: Is it a friend or a foe? Here are some friendly insects – natural enemies of pests – you might encounter.

Lady beetles

Red lady beetle with black spots on a green leaf
This sevenspotted lady beetle is pretty easy to recognize.

Adult lady beetles are some of the most easily recognized natural enemies. For example, most would know that this sevenspotted lady beetle is a friend. But lady beetles come in many different stripes – err – spots. Here’s another lady beetle that might not be as familiar, but is an equally good predator.

oblong pink beetle with many black spots on a yellow dandelion
You might be less familiar with the pink spotted lady beetle, but it’s a friendly insect you should get to know.

Immature lady beetles look very different from adults. But the larvae are voracious predators, and leaving the pupae undisturbed means you’ll soon have more adult lady beetles around. In addition to aphids, lady beetles will eat whiteflies, thrips, mites, and eggs of other insects.

On the left a segmented, black and orange insect on a leaf. On the right, a more round black and orange insect on a leaf.
An immature (larval) lady beetle on the left is a great predator. The pupal (resting) stage of the lady beetle on the right will soon turn into an adult.

If you’d like to identify the lady beetle species you’re finding in your garden, check out these resources from The Lost Ladybug Project.

Lacewings

Similarly, while you may be more familiar with the adult lacewings (which can be green, as well as brown), in some lacewing species it’s only the larvae with their formidable jaws that are munching on pests (generally the same ones that lady beetles eat). Adult lacewings will eat pollen and nectar (and some species also eat other insects).

On the left, a brown mottled insect with large jaws, and on the right, a green insect with lacy wings.
Larval lacewings (left; this one is magnified) look much different than adult lacewings (right).

Minute pirate bugs

Black and white insect with eyes sticking out of the side of its head.
This picture of a minute pirate bug is magnified. They are no more than a quarter of an inch long.

This friendly bug (and it is a true bug!) can be hard to spot because it’s so tiny; truly minute. If you get a chance to look at this (< ¼”) insect with a hand lens, you’ll notice a white diamond shape towards its rear, with a black diamond shape behind its head. At least that’s what the adults look like. Here’s one searching for thrips on a sign at a corn maze. The immature (or nymph) minute pirate bugs are orange and look not much like the adults. In keeping with their size, minute pirate bugs eat small pests like aphids, mites, thrips, and insect eggs. They also eat pollen and nectar, which is probably why I often bring a few inside with me when I cut flowers from my garden. Those same mouthparts that are great at eating pests can also give you a small (but startling) pinch. But it doesn’t hurt much, and if you leave them undisturbed, both you and the pirate bugs will be happier.

Hover flies

Four pictures of hover flies. Some are smaller with narrow bodies, while others are larger with rounder bodies. One is even a little fuzzy.
Adult hover flies come in different sizes, shapes, and stripe patterns, but they are great pollinators and good friends to have in the garden or field.

Sometimes hover flies (also called syrphid flies) are incorrectly called sweat bees. Sweat bees are true bees. While many hover flies are black and yellow striped, and some look quite a lot like bees, they are flies. True to their name, hover flies are often spotted hovering around flowers. Here are two tips for distinguishing hover flies from bees:

  • Hover flies have big eyes that take up most of their head; bee eyes are usually smaller and oval-shaped
  • Hover flies have only two wings; bees have four

Immature (larval) hover flies are the ones that are eating pests on your plants. They look like small worms, and may come in slightly different sizes or shapes. But they love to eat aphids, whiteflies, and scales.

Translucent green maggot with brown stripe down the middle feeding on black aphids on a plant.
I’m not 100% sure if this is a hover fly larva, or another predatory fly larva. But this will give you some idea of what you’re looking for.

(Predatory) stink bugs

brown stink bug eating a black, yellow, and white striped caterpillar
Carnivorous (as opposed to plant-eating) stink bugs are generalist predators, so you may sometimes find them eating other beneficial insects.

None of us are happy to find stink bugs (usually brown marmorated stink bugs, to be specific) invading our homes, but there are many more stink bug species, and some of them are excellent predators. I know, the one above happens to be eating a monarch caterpillar, but they will eat pest caterpillars and other insects, too. The advantage of generalist predators is that they will eat all kinds of pests. The disadvantage is that they may also eat some insects that aren’t pests. This is just part of a balanced ecosystem in your garden or field.

It can be difficult to distinguish a predatory stink bug from a pest stink bug, without looking closely at its proboscis (straw-like mouthparts used for sucking either plant or bug juices), but Virginia Cooperative Extension has a nice field guide available here, which can help. Or you could spend some time observing the stink bug to see if it’s eating a plant or another insect.

Spiders

From left to right – black and yellow spider, cream-colored spider on a red flower eating a bee, brown daddy long legs on green foliage.
These are just a few of the eight-legged friends you might find in your garden of fields.

Spiders (examples on the left and middle in the above picture) and harvestmen (example on the right) may make some people feel uncomfortable, but both are generalist predators, and therefore good to have around. The spiders you are likely to find in New York are nearly all non-venomous, so welcome them without fear. More info about common spiders of NY can be found here.

Wasps

On the left, a black wasp with yellow stripes on a red flower bud, and on the right, a black and orange wasp on pink milkweed flowers
Just two of many wasps you might find visiting flowers in your garden or field.

If you are growing a diversity of flowers that produce lots of pollen and nectar, you may also see a diversity of wasp visitors. Most are unlikely to sting you, and even wasps like yellow jackets or hornets that may sting you are likely also looking for caterpillars and other insects to eat. Many wasps (including tiny ones you won’t notice and larger ones that you will) can also kill pests by laying their eggs in or on them. These are called parasitoid wasps. So if wasps aren’t hurting anyone, leave them alone. Of course, if stinging wasps are building a nest on or near a structure where they are likely to be disturbed by people, action may be required. Learn how to use IPM for stinging wasps here.

Bright green caterpillar with a horn at its rear end, with about a dozen white capsules (wasp pupae) attached to its back.
This hornworm was parasitized by a wasp, and its tomato-munching days are numbered. New wasps will emerge from the white sacks on its back.

Other flies

Large fly with thick thorax, long abdomen, and bristles on legs and around mouth
Robber flies may not look very pretty, but they are good predators to have around.

Besides hover flies, there are a whole lot more flies visiting gardens and fields, and many will either eat or parasitize pests. The robber fly pictured above is especially large and is a great predator. Of course, there are plenty of flies you don’t want around. For more info on IPM for flies around your home, you can look here. You can find resources for managing livestock flies here.

And there’s more!

This is by no means an exhaustive list of insect natural enemies. For example, there are a variety of other true bugs, including big-eyed bugs, damsel bugs, assassin bugs, and ambush bugs that will eat pests in your garden or field. The ambush bugs are the easiest to recognize.

Brown and cream colored bug perched on the cream and pink speckled petals of a zinnia flower
This ambush bug isn’t too hard for you or I to spot on this zinnia. Hopefully its prey won’t see it so easily.

And, this list  doesn’t touch on most of the ground-dwelling natural enemies (although some spiders are predominantly found on the ground. I’ll cover those in another post.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

This work is supported by:

  • New York State Department of Agriculture and Markets
  • New York State Department of Environmental Conservation
  • The Towards Sustainability Foundation
habitat at home, home gardens

When can I clean up my garden…and still protect beneficial insects?

Garden bed next to a house still full of dead plant stems from last year’s flowers
Don’t clean up your garden too early this spring! Pollinators and natural enemies of pests need to stay cozy a bit longer.

The days are getting longer and (sometimes) warmer, trees are beginning to leaf out, spring bulbs are blooming, and lots of people are anxious to clean up their gardens. But you may have heard that cleaning up your garden too early is bad for pollinators and other beneficial insects like natural enemies of pests. Is this true? How long do you need to wait?

What’s the concern with early garden clean-up?

There are two aspects of garden clean-up that pose a risk to beneficial insects in your garden: cutting out dead stems and clearing away leaves or other debris on the ground. Some species of wild bees nest in dead stems, so cutting down and disposing of these stems before the bees emerge for the spring is problematic. Dead leaves and other plant debris on the ground provide shelter for natural enemies like lady beetles, fireflies, and ground beetles. Pristinely-raked garden beds remove this shelter. You can read more about the benefits of messiness in this ThinkIPM blog post.

When should I clean up my garden?

First, please don’t clean your garden up in the fall. With the exception of removing and disposing of diseased or insect-infested plants (especially annuals), let your garden rest in the fall.

Ok, so you’ve waited until spring. But when? It’s complicated. You are trying to protect a diverse group of wild bee species, who are nesting in diverse settings (including both the ground and dead plant stems), in addition to many different species of beetles, spiders, and other arthropod natural enemies of pests. It should come as no surprise that all of these different arthropods emerge from their winter homes at different times. For example, around here (NY) bumble bees, carpenter bees, mason bees, and mining bees emerge earlier (early April) than sweat bees (May). Even within two species of mason bee, researchers found that the temperature during the winter, the sex of the bees, and their size all significantly impacted when they would emerge in the spring (varying by up to 40 days). Winter temperatures also impact when alfalfa leafcutting bees and other bees emerge.

metallic green bee perched on a pink cosmos flower
Sweat bees nest in the ground, and emerge a bit later in the spring than some other bee species.

So what should I do?

First, don’t let the complexity of the situation paralyze you. Can you leave just a part of your garden “messy” year round, while you clean up the flower bed right next to the street? Do it. Don’t let the perfect become the enemy of the good. You might also consider making or purchasing a sign that lets your neighbors know why you are keeping your garden a bit untidy. It could spark some interesting conversations, and maybe you’ll start a new trend!

Second – and related to the first suggestion – remember that diversity is a strength. No single way of gardening is good for all beneficial insects. For example, mulch provides shelter for beetles (many of which are predators), but ground nesting bees need bare ground. Different parts of your yard or garden can support different beneficial insects.

Third, the Xerces Society offers some guidelines for timing garden clean-up by watching the weather and what’s happening to other plants around you. However, this advice is specifically for protecting bees, and doesn’t address the needs of natural enemies of pests.

  • In the northeast, don’t start garden clean-up until your taxes are submitted. But realize that even waiting until mid to late April is still too early for some bee species.
  • The cool season grasses we usually have growing in our lawns generally require the soil to be about 50° F in order to start growing. Wait to clean up your gardens until you need to mow your lawn regularly. But always remember to mow high.
  • Wait until apple and pear trees finish blooming. In the northeast U.S., apricots, peaches, plums, and cherries will bloom early (when many ground-nesting bees are emerging), but apples and pears won’t finish blooming until mid-May.
  • To be extra safe, wait until you are ready to plant tomatoes (when night temperatures are consistently above 50° F). At least in my part of NY, this may not be until late May.

Fourth, if you feel like you absolutely can’t wait to do some garden clean-up, change how you dispose of the debris you remove. Cut back last-year’s dead stems and pile them loosely in a corner of your yard (rather than bagging them and taking or sending them to a compost facility). Insects that have yet to emerge from the stems can still do so. Once you’re well into summer, feel free to compost this debris. But remember that your landscaping choices can also create spaces for ticks to hang out.

a pile of dead pant stems next to dead leaves, a fence, and an evergreen tree
I did clean up some garden beds in my front yard a bit on the early side this spring. But I piled the stems I cut in a back corner of my backyard.

Happy gardening!

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

Community IPM, habitat at home, home gardens

Finding plants that feed friendly insects

bouquet of yellow, orange, pink, red, purple, and white flowers
The prospect of growing cut flowers is so very appealing during February in upstate NY!

I don’t know about you, but this time of year I start daydreaming of all the plants I can’t wait to grow in my garden once it gets warm. The virtual and hard copy seed catalogs that fill my mailbox and my inbox are full of so many beautiful pictures and inviting suggestions. How to choose?

Well, if one of your goals for your 2021 garden is to provide good habitat for beneficial insects that eat pest insects (natural enemies of pests), here’s some advice…

Look for pollen and nectar producers

Flowers that provide plenty of pollen and nectar make great habitat for natural enemies. This is because some natural enemies also eat pollen or nectar (or both). For example, this adult hover fly feeds on the pollen and nectar produced by this bachelor’s button.

Black and yellow hover fly visiting a purple flower made up of a cluster of small petals
An appreciation for bachelor’s button flowers is something I share with this hover fly.

Flowers that produce pollen and nectar also attract other insects that natural enemies feed on (including lots of neutral insects, so the net effect is positive). This ambush bug is hanging out on a zinnia waiting for other insects to wander by and become lunch.

Dark brown and yellow insect on a zinnia with cream-colored petals flecked with pink
This ambush bug doesn’t seem too well camouflaged to me, but hopefully its prey didn’t notice it.

How do you know if a plant will produce flowers rich in pollen and nectar? Well, plants marketed as being good for pollinators are often a good bet, since bees, butterflies, and other pollinators also feed on pollen and nectar. Be aware that sometimes – but not always – “fancy” cultivars (with double blossoms or exotic colors) do not provide the same pollen and nectar resources as the “plain” cultivars or simply native species. You can read a bit more about this in my post from last spring.

Flower shape matters

While some bees have long tongues that help them reach into deep, tube-shaped flowers, lots of natural enemies (like flies, small wasps, and beetles) prefer small, shallow, and open flowers. The pollen and nectar are easier to access, and these flower shapes also give them a nice spot to land or sit.

Two pictures; on the left a bee is feeding on one of many small, tubular purple flowers; on the right an orange and black beetle is feeding on tiny white flowers.
The bee on the left has no problem reaching into these tubular flowers. The soldier beetle on the right is happy on the small boneset flowers.

Plan for season-long blooms

Natural enemies need food (whether it’s pollen and nectar or other insects) from early in the spring until late in the fall. If you only have blooms in July and August, the natural enemies will be very hungry, and will find another spot to hang out. Of course, continuous blooms have aesthetic value, too.

While annuals tend to bloom for a longer period of time during the growing season (especially if you pick off dead blooms), it can be hard to find annuals that bloom early (at least in NY).

Plant with a large cluster of small yellow flowers
Golden alexanders is an early-blooming perennial. I took this picture in the middle of May.

Including some early-blooming perennials will feed your natural enemies before your annuals take off. This site lets you search for plants by a variety of characteristics, including when they bloom.

Put away those pesticides!

Or at least pause and assess whether you really need them and what impact they might have on natural enemies and other non-pests before you use them. Of course, you must always read and follow the label on any pesticide, no matter where you plan to use it. The label is the law!

Plants that don’t bloom are still useful

For example, bunching grasses not only provide some visual contrast to blooming plants, but they make great shelter for predatory beetles, spiders, and other insects.

Clump of grass with blue-green blades surrounded by a few weeds
Grass that grows in clumps like this little bluestem provides shelter for ground-dwelling natural enemies.

If you love spreadsheets like me…

While looking for pollinator-friendly plants is an easy way to choose plants that will probably support natural enemies, sometimes I am asked “yes, but if I want to attract this specific natural enemy, what should I plant?” So I reviewed university research and extension resources from around the United States to see which plants have been documented to support specific natural enemies. Here’s the link to that spreadsheet. If you want the “cliffs notes”, here are the plant families that had the largest number of species documented as supporting natural enemies:

  • Aster (same as the daisy or composite family)
  • Carrot (same as the parsley family)
  • Mint
Yellow flower with a brown center (blackeyed susan) being visited by a lady beetle
Lots of members of the aster (daisy, composite) family produce plenty of easily-accessible pollen to feed natural enemies like this lady beetle.

Got a pest and you’re wondering which natural enemies will eat it? There’s a chart for that, too!

So, what will you be growing in 2021? I already placed my first seed order (hint: it included a few different kinds of both zinnias and sunflowers), but I can’t promise I won’t place a second one.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

Community IPM, habitat at home, home gardens, IPM, ornamentals, pollinators

Creating beneficial habitat at home: Fall update

The picture on the left was taken on May 2, 2020 and shows a small yard on the side of a house with mostly grass and a few small mulched garden beds with hostas and daffodils growing in them. The picture on the right was taken on August 14, 2020 and shows the same yard next to the house, this time full of blooming flowers and a squash plant.
Having before and after pictures really helps me appreciate how far my beneficial insect habitat (plus a few vegetables thrown in for good measure) have come!

Well, the days are getting shorter, the air is getting cooler, and pumpkins are starting to show up on front porches. I guess it’s time for me to admit that fall is coming. So it seemed like a good time to provide an update on my efforts to establish habitat for beneficial insects around my home. If you need to catch up on this project, you can read more about site selection, plant selection, and weed control in previous posts.

#BeneficialHabitatAtHome in pictures

Overall, I’m pretty happy with how the garden turned out this first year! If you follow me on Instagram or Twitter, you’ve seen some of these pictures already.

I attracted quite a few pollinators…

A collection of eight pictures in two rows. Pictures in the top row (A-D) show a small bee on a red strawflower, an orange and black monarch butterfly on a zinnia flower that is cream colored with pink speckles, a small bee on a yellow calendula flower, and two bees on a pink cosmos flower. The bottom row shows a smaller green bee on a pink cosmos flower, a bee on a red and yellow blanketflower, a yellow and black striped hover fly visiting a purple bachelor’s button, and a small orange and black butterfly visiting an orange and yellow zinnia.
These are just some of the pollinators that visited my (A) strawflowers, (B) zinnia cultivar ‘Candy Cane Mix’, (C) calendula cultivar ‘Remembrance Mix’; (D) and (E) cosmos, (F) blanketflower, (G) bachelor’s buttons and (H) ‘Persian Carpet’ zinnia.

…and natural enemies.

Four pictures, clockwise from top left: black and yellow ambush bug on a cream-colored zinnia flower flecked with pink speckles; a red ladybug with black spots on a leaf next to a zinnia bud; a pink ladybug with black spots perched on a pale pink and yellow zinnia flower; a translucent yellow-green “worm” amongst black aphids on a plant stem.
Most of the natural enemies I spotted this summer were ladybugs, like the seven-spotted ladybug in B and the pink spotted ladybug in C. But I also saw an ambush bug (A) and a hover fly larva (D). I saw plenty of adult hover flies, but the larvae are a bit less conspicuous.

I also picked a lot of cut flowers!

A small vase of yellow, orange and red zinnia and calendula flowers next to a larger vase of mixed flowers (sunflowers, cosmos, blanketflowers, calendula, bachelor’s button, and zinnias) in red, yellow, orange, pink, and purple.
Admittedly, one of my goals in creating this habitat was to be able to pick cut flowers for myself and others this summer. I was hoping that I could grow flowers that would be attractive both to people and natural enemies of pests. I think I succeeded!

Plant establishment success

This spring, I planted four perennials: arnica (Arnica chamissonis), blanketflower (Gaillardia aristata), echinacea (Echinacea purpurea), pyrethrum daisy (Chrysanthemum coccineum), and ‘Chim chiminee’ rudbeckia (Rudbeckia hirta). I started some blue vervain from seed, but by the time I’d figured out that stratification was needed, it was pretty late in the spring. The seedlings that did emerge didn’t survive. The blanketflowers and rudbeckia bloomed already this first year.

A small mulched garden bed next to a house with yellow and orange rudbeckia flowers blooming on the left and red blanketflowers blooming on the right. There are also some yellow calendula blooming around these plants.
Although they are perennials, the ‘Chim Chiminee’ rudbeckia and the blanketflowers bloomed this first year, and also looked nice as cut flowers.

The arnica, echinacea, and pyrethrum daisy put their energy into vegetative growth, and hopefully they will bloom next year.

Composite showing pictures of three non-flower plants growing on mulch. One has elongated heart-shaped leaves (A), one has leaves like those on a carrot (B), and one has longer, narrower leaves (C).
Three of the five perennials I planted this spring are growing, but haven’t bloomed this year: (A) echinacea, (B) pyrethrum daisy, and (C) arnica. Hopefully next year!

Not surprisingly, the annuals produced abundant blooms. Others have noted that there can be value in  mixing annuals with perennials when you are establishing habitat for beneficial insects. The annuals will provide abundant flower resources right away, while it may take a few years to achieve peak bloom production on perennials.

Eight pictures of different flowers in two rows. Top row left to right (A-D): yellow sunflower, pale pink snap dragon, bachelor’s buttons in various shades of purple, yellow and orange ‘Persian Carpet’ zinnias. Bottom row left to right (E-H): pink cosmos, yellow calendula, red poppy, zinnias in two colors - white with pink speckles and yellow.
A few glamour shots of some of the annuals I grew this year: (A) sunflower, (B) snap dragon, (C) bachelor’s buttons, (D) ‘Persian Carpet’ zinnia, (E) cosmos, (F) calendula, (G) poppy, (H) zinnia.

Fall planting

Hopefully this is not the first time you’ve heard that “fall is for planting”. In preparation for this, I started some butterfly milkweed (Asclepias tuberosa) and columbine (Aquilegia sp.) seeds back in late July so that I’d have some seedlings ready to go in the ground this fall. The columbine benefitted from spending about three weeks in my fridge (after I’d seeded them in moist potting mix) before giving them some light and warmth. (Don’t judge me. The real question is why not reserve one shelf of your fridge for seed storage and germination!) Columbine seedlings will go in my backyard where there’s less sun.

seven small peat pots filled with potting mix, with a few seedlings growing out of each
Some of the seedlings I’m planting this fall.

I also snagged a few seed heads from the golden alexanders and the blackeyed susans (also Rudbeckia hirta, but the straight species) in our beneficial insect habitat research plots. I’m going to plant them this fall, too and hope to see some seedlings next spring.

A mixture of round and elongated seeds in a pile in the middle of a woman’s outstretched hand
I’ll let the winter weather scarify these golden alexander and blackeyed susan seeds, preparing them to germinate in the spring.

Whether I’m working remotely next year or not, I’ll keep providing periodic updates on my efforts to establish habitat for beneficial insects around my house.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture
  • New York State Department of Agriculture and Markets
Community IPM, habitat at home, home gardens, IPM, ornamentals, pollinators

Beneficial habitat at home: Weed control and mid-summer update

Red and black lady beetle on zinnia leaf
With all the Japanese beetles I’ve been pulling off my zinnias, it was a pleasant surprise to find a more friendly beetle!

It’s been two months since I since I wrote about the plants I selected to provide habitat for beneficial insects around my home. Today I’ll talk a bit about weed control and how my spring transplants are doing.

Weed control

I have mentioned before that managing weeds turns out to be far more than half the battle when it comes to establishing perennial wildflowers as habitat for beneficial insects. Based on the results from the habitat plots we planted on the edges of our Christmas tree research field, I decided to use mulch for weed management in my home gardens. While mulch does add extra cost, after you make the initial investment of time to spread the mulch, it really cuts down on the time required to manage weeds during the rest of the season. I had a relatively small area to mulch, and was able to purchase some relatively inexpensive mulch made from the brush and leaves picked up by my city. Also, while I haven’t tested the organic matter content of my soil, just digging up some of the grass told me that my soil could use more organic matter. The mulch will eventually help with that as it breaks down. One downside to mulch is that it could block access to the soil for ground-nesting bees. There are some spots of bare ground in other parts of my yard, and perhaps next year I will be a little more deliberate about keeping some areas bare to support these pollinators.

Several freshly-mulched garden beds with small seedlings alongside a house
I decided to use mulch for weed control in my home beneficial insect habitat.

If mulch isn’t for you, you can read more about different weed management strategies we are demonstrating in our habitat plots.

How are things growing?

Like many (but not all) New Yorkers, I have found myself frequently wishing for more rain this summer. According to the closest NEWA station, we only got 1.3 inches of rain in May, 1.44 inches in June, and 1.48 inches in July (so far). This spring and summer is an excellent illustration of why experts recommend transplanting perennials in the fall, and not in the spring. Hot and dry are not ideal conditions for young seedlings just trying to get started. We often get more rain in the fall, and the cooler temperatures mean the transplants are subjected to less stress.

I started my plants from seed, and most of my seedlings were pretty small when I transplanted them the first week of June.

Three seedlings surrounded by mulch just starting to produce their second set of true leaves
This picture was actually taken about 2 weeks after I transplanted my seedlings. They were a little on the small side.

I admit that I also didn’t harden off my seedlings exactly the way you are supposed to. After losing some un-protected plants to marauding bands of squirrels, and lacking a protective structure that would let me keep my seedlings in full sun, I hardened them off on my screen porch. Moving from this environment to the south side of my house in full sun was a bit of a shock, especially when it got so hot and dry so soon after transplanting. I’ve done a lot of watering over the past month and a half, and I still lost more of my perennial seedlings (and some annuals) than I had hoped.

One seedling, surrounded by mulch
There were supposed to be three echinacea plants in this picture. At least one of them survived!

In spite of these obstacles, quite a few of my transplants survived. The blanketflowers (Gaillardia aristata) are the only perennials that look like they will bloom this season. If I had bought seedlings from a local nursery, they might have been bigger and might have established faster. But I can be patient.

Plant with scalloped leaves and a very young flower bud forming at the top
I think I can see the beginnings of a flower bud on this blanketflower.

You already saw the echinacea. Here are some of the other perennials.

Two seedlings with oblong and very hairy leaves on the left (rudbeckia); one seedling with leaves that look like a carrot on the right (pyrethrum daisy). All are growing surrounded by mulch.
Some of the surviving rudbeckia (left) and pyrethrum daisy (right) seedlings.

Not surprisingly, the annuals have grown faster. (Remember, they’re in a race to reproduce and pass on their genes before winter returns!)

Japanese beetles are eating the common zinnias.

Several Japanese beetles crawling over zinnia leaves with many holes
A small consolation is that the Japanese beetles seem to like my roses even more than they like the zinnias. The roses are functioning as a sort of trap crop.

But they are leaving the ‘Persian Carpet’ zinnias alone. It turns out these are a variety of Mexican zinnias (Zinnia haageana), which is a different species than the common zinnias (Zinnia elegans).

Small yellow and red zinnia flower growing on a plant with small, narrow leaves
‘Persian Carpet’ zinnias have smaller flowers, smaller leaves, and no Japanese beetle damage, even though I planted them right next to my roses.

I’ve been picking the Japanese beetles off by hand (adding them to my compost bin after they drown). I found the beetles to be more sluggish in the evenings (although admittedly I wasn’t out at the break of dawn), and a colleague recently shared this article with me that suggests that hand-picking Japanese beetles in the evening is indeed the best option. This strategy has not prevented all damage (especially on my roses), but I think my plants will survive. And I admit I haven’t picked them every single day.

Looking down into a yogurt container half-filled with water and many dead Japanese beetles
Japanese beetles picked off of my plants and drowned

The snap dragons have started blooming.

Pink, peach, and white snap dragon flowers in bloom
I planted snap dragons mostly because I like them as cut flowers, although I have seen reports that they support bees.

And so have the calendulas.

Plant with yellow flowers starting to open
Calendula in bloom.

I’ve seen hover flies on the bachelor’s buttons. Remember the adult hover flies are pollinators, while their larvae are voracious aphid predators.

Pink and purple flower with a black and yellow striped fly visiting it
I’ve seen a few hover flies visiting the bachelor’s buttons.

The cosmos and sunflowers (that survived the squirrels and a local rabbit) haven’t started blooming yet, but they’re looking good!

Sunflower and cosmos plants growing well next to the chimney of a house
The squirrels must not have found my first planting of sunflowers, because they and the cosmos planted with them look great!

This spring I ran out of space to start seeds indoors, and since fall is a better time for planting I saved a few perennials for the fall. Last week I seeded butterfly milkweed (Asclepias tuberosa) and some columbine. In the absence of grow lights, and since I’m not an expert transplant producer, I wanted to give these seedlings a good two and a half months to grow before I transplant them.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
Community IPM, habitat at home, home gardens, IPM, pollinators

Choosing plants for Beneficial Habitat At Home

light pink flower with a fuzzy bee crawling on it
A bee gathers pollen from a cosmos flower.

Recall from this post that I’m creating habitat for beneficial arthropods (including insects, spiders, predatory mites, etc.) around my house this spring. Because more of us may be doing this while we’re staying home to keep each other safe, I’m sharing my experiences here (as well as on Twitter and Instagram). The previous post covered site selection. Today I will talk about the species I’ve chosen (and why).

What I’m planting in my yard

Sunny yard alongside a house with several freshly-dug garden beds
My side yard faces south and gets the most sun. But it’s a pretty small area and I want it to look reasonably tidy. I’m still building rapport with my neighbors.

The front and side yards get plenty of sun (because they face south and west), so I’m looking for plants that thrive in full sun. And I’ll admit that I’m interested in more than just supporting beneficial arthropods. I also want my front and side yards to look reasonably nice. (I don’t want to make enemies of my new neighbors!) And I want to grow flowers for cutting. So I am not sticking strictly to native plant species or to perennials. Some plants I picked just because I thought they looked nice. For example, I was beguiled by ‘Chim Chiminee’ Rudbeckia. The pollen and nectar produced by the native species may have been bred out of this variety. I’ll find out. I also just love ‘Persian Carpet’ zinnias.

Plants growing in a large clump with smaller flowers in combinations of yellow, orange, and red.
I grew these ‘Persian Carpet’ zinnias in my garden last year. I love the mix of colors and the abundant blooms that last well when cut.

I’ve started a lot of plants from seeds I had in my fridge (e.g., snap dragons, echinacea, bachelor’s buttons). Others I will direct-seed outside (e.g., sunflowers, zinnia, cosmos), and I may also purchase some transplants from local nurseries (many have great strategies for safe curbside pick-up!).

Several small seedlings growing in paper pots.
I’m starting some plants from seed at home. Using paper pots means that I can compost them when I’m done, and not worry about carrying pathogens over from year to year on plastic pots that I would have to wash very thoroughly after use. Once a plant pathologist, always a plant pathologist!

Choosing plants for beneficial arthropods – the basics

Which plant species to grow to support beneficial arthropods (whether it’s pollinators or natural enemies of pests, or both) is a common question. The answer is both straight-forward, and also complicated. In addition to shelter and protection from pesticides, all beneficial arthropods need something to eat. In general, plants that provide plenty of nectar and pollen help to provide this food. Many natural enemies of pests will also eat pollen or nectar (e.g., at certain life stages, or as a supplement to the pests they eat). Even if they don’t, the pollen and nectar will often attract small arthropods that natural enemies can feed on. So, the simple answer is that a plant that produces lots of pollen and nectar, will thrive in the setting where you want to plant it, and is not invasive is a good choice for supporting beneficial arthropods. Plants that are marketed as supporting pollinators are easy to find and are likely to also support natural enemies.

Bright purple flower with three petals with a yellow and black striped fly perched on it
This Ohio spiderwort (Tradescantia ohiensis) in our beneficial arthropod habitat plots is being visited by a hover fly. Hover fly larvae are excellent aphid predators!

But, of course, it’s not exactly that simple…

Choosing plants – natives, cultivars, and more

Many people ask if they should only grow native plant species, or if it’s ok to plant cultivated varieties of native species, or non-native species. (Hopefully it’s obvious that you should never plant an invasive species in your yard!) Annie White at the University of Vermont wrote a 254-page dissertation on the topic. These two sentences from her abstract summarize her findings nicely: “Our study shows that many insect pollinators prefer to forage on native species over cultivated varieties of the native species, but not always, and not exclusively. Some native cultivars may be comparable substitutions for native species in pollinator habitat restoration projects, but all cultivars should be evaluated on an individual basis.” You might also want to take a look at this article from the University of Maryland and this one from the Xerces Society. In summary, I would say it’s up to you whether you want to plant exclusively native species, or not.

According to David Smitley from Michigan State University, perennials are usually better choices for bees than annuals, but this article includes a list of annuals that are attractive to bees. Alyssum is an annual that definitely supports natural enemies, but many of the other annuals on this list may also support natural enemies.

Deep orange sunflower with a bee visiting it, starting to gather pollen
Although they are annuals, sunflowers are still very attractive to bees. Also, I like them as cut flowers.

Choosing plants – attracting specific arthropods

If you are trying to attract very specific natural enemies (e.g., parasitoid wasps, lady beetles) your plant choice can also get more complicated. Some great work has been done by researchers at Michigan State University documenting which arthropods (pollinators, natural enemies, and some pests) visited different plant species native to Michigan. They also offer a simplified summary. “Habitat Planning for Beneficial Insects” from the Xerces Society includes notes in the charts at the end about which beneficial insects are particularly attracted to the species listed. This resource from Oregon State University describes some specific plants and the arthropods they support. Finally, although this study was conducted in the United Kingdom, there might be some relevance to the Northeast U.S.

Update: During Summer 2020 (while I was doing less field work), I reviewed the literature I could find on the value of specific plants for specific natural enemies. Here is the spreadsheet I compiled.

Lists and searchable databases

In addition to the resources already listed, you may find the following helpful in selecting plants:

If you want to focus on native plants, there are many organizations committed to supporting local native plants…too many to list here, but some online searching may turn up an organization that is local for you.

My current plant list

This table lists what I either have already seeded (inside or outside), or am planning to direct seed outside when it gets a little warmer. In addition to the common, scientific, and cultivar name of each plant and whether it is a perennial or an annual in NY, I also included information about why I chose it. I only marked plants as supporting bees or natural enemies if I could find documentation of that fact in the resources above. It may be that more of the plants on this list support beneficial arthropods. If you have additional information on these plants, please let me know! In some cases (for example, zinnia) the species is reported to support beneficial arthropods, but I don’t know if the cultivars I’m growing will. In many cases, the decorative value of the plant was a big part of why I chose it. The arnica? Well, I just saw that in a seed catalog this winter and ordered some on a whim.

Common name Scientific name Cultivar Annual or Perennial in NY Bees Natural enemies Decorative
Arnica Arnica chamissonis perennial
Bachelor’s buttons Centaurea cyanus annual X X
Blanketflower Gaillardia aristata Burgundy perennial X X X
Blue vervain Verbena hastata perennial X
Calendula Calendula officinalis Remembrance Mix annual X X
Celosia Celosia argentea cristata Red Flame annual X X
Cosmos Cosmos bipnnatus Dwarf Sensation annual X X X
Echinacea Echinacea purpurea perennial X X
Marigold Tagetes erecta Senate House annual X X
Poppy Papaver somniferum Frilled White Poppy annual maybe X
Poppy Papaver sp. seed saved by a colleague annual maybe X
Pyrethrum daisy Chrysanthemum cocineum perennial X
Rudbeckia Rudbeckia hirta Chim chiminee perennial maybe X
Snap dragon Antirrhinum majus annual X X
Strawflower Xerochrysum bracteatum annual X
Sunflower Helianthus anus Mammoth Greystripe annual X probably X
Sunflower Helianthus anus Evening Sun annual X probably X
Sunflower Helianthus anus Sonja Dwarf annual X probably X
Zinnia Zinnia elegans Queen Lime with Blush annual maybe X
Zinnia Zinnia elegans Candy Cane Mix annual maybe X
Zinnia Zinnia elegans Benary’s Wine annual maybe X
Mexican zinnia Zinnia haageana Persian Carpet annual maybe X

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation