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.
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.
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.
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!
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
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
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.
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.
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.
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).
Larval lacewings (left; this one is magnified) look much different than adult lacewings (right).
Minute pirate bugs
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
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.
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
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
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
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.
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
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.
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 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.
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.
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.
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).
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.
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
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.
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…
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.
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!
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.
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.
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.
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.
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.
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
Japanese knotweed is very invasive. Photo credit: Amara Dunn, NYSIPM
At a previous residence, Japanese knotweed was the bane of my backyard gardening endeavors. Masses of these invasive plants can easily stifle native or non-invasive plants. The roots grow deep and even small pieces left in the ground can re-grow new plants. I used frequent hand-pulling and digging in an attempt to keep it in check, and I knew that if I stopped it would just grow back. For more information on this invasive weed, refer to this excellent fact sheet.
Close-up of Japanese knotweed leaves. Photo credit: John Cardina, The Ohio State University, Bugwood.org
I have read that you can cook and eat it, but I haven’t tried. And no matter how delicious it might be, it would still be horribly invasive. While bees will visit the flowers late in the summer, there are better ways to feed the bees.
Japanese knotweed can provide food for pollinators, like this wasp.
You may have heard that Cornell researchers led by Dr. Bernd Blossey released the Knotweed Psyllid (Aphalara itadori) in June 2020 in Tioga and Broome counties as a potential biocontrol agent for this invasive weed. This release came only after thorough testing and permission from the U.S. Department of Agriculture, since this insect is native to Japan. You can learn more about the process of using classical biocontrol to manage weeds here. Be assured, many precautions are taken before non-native species are intentionally released in the U.S.
Tiny psyllids released in Tioga County in an attempt to control invasive Japanese knotweed. Photo credit: Bernd Blossey, Cornell University
Unfortunately, attempts to establish this insect in both the United Kingdom and Canada have not been successful. Preliminary results from the NY releases suggest that this psyllid will not be the biocontrol solution we need for Japanese knotweed. Most of the insects that were released do not seem to have survived and even when the insects were protected in cages put around the knotweed plants, they didn’t reduce the growth of the plants.
It seems that if we are going to solve this weed problem with biocontrol, we will need to find other insects from the native range of Japanese knotweed. Assessing these insects prior to release in the U.S. will be a lengthy process, so in the meantime keep using other IPM tools for this invasive weed.
If you’d like to learn more about this project, the New York Invasive Species Research Institute is hosting a webinar on September 30, 2020 at 11:00 AM.
This post was written by Amara Dunn (NYSIPM) and Dr. Bernd Blossey (Cornell Department of Natural Resources).
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.
I decided to use mulch for weed control in my home beneficial insect habitat.
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.
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.
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.
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.
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.
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).
‘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.
Japanese beetles picked off of my plants and drowned
The snap dragons have started blooming.
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.
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.
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!
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
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
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.
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!).
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.
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.
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
I was so excited to check on our Christmas tree and beneficial insect habitat plots on this sunny May day!
Thanks to everyone who’s been following the project I’ve been working on with Betsy Lamb and Brian Eshenaur to establish (and document the impacts of) habitat for natural enemies of pests and pollinators (collectively, beneficial insects) around a research planting of Christmas trees! For many people, life does not look the same as it did in January, and we are no exception. Don’t worry, we and the excellent Field Research Unit staff at Cornell AgriTech will be maintaining our research beneficial insect habitat plots (and the Christmas trees around them) so that we can continue to do research here in future years. But, in the interest of keeping people safe and working remotely as much as possible, we won’t collect insects this season. I will be going out about once a week to take pictures of both plants and insects (by myself, with a mask on hand just in case). You can see these pictures on either my Twitter or Instagram accounts.
Zizia aurea (golden alexander) is the earliest-blooming plant species we have in our beneficial insect habitat plots. And it wasn’t blooming yet the first week of May.
There’s also a new project you can follow this spring and summer (here, and on Twitter and Instagram)! I recently moved into a new house, and was already planning to put in a (mostly flower) garden, including plants that support beneficial insects. Since many people are doing more things at home, this seemed like a good year to share my experience establishing habitat for beneficial insects in a home garden.
First step? Site selection. My backyard is a bit shady (and I suspect it will be shadier when the leaves come out). You can’t tell from this picture, but the ground also tends to be a little squishy after it rains.
Even before the leaves have come out, I can tell that my backyard is not going to be the sunniest.
The front and side yards face south and west and are drier.
The side yard at my house faces south, and gets more sun (except first thing in the morning).
In my experience, the list of plants that support beneficial insects is longer if you have plenty of sun and reasonably dry soil. This doesn’t mean that you can’t support beneficial insects in a wet and/or shady spot. But you need to choose plant species carefully. You will be more successful if you choose plants that will thrive in the conditions you have. More on plant selection in a later post.
In addition to simple aesthetics, another important part of site selection around the home is knowing what’s underneath the ground. My local utility company provided information about getting water, gas, electric, and internet service lines on my property marked before I start digging. They recommended marking these lines even if I’m just planning to dig by hand with a shovel. If you are planning to use larger equipment, this is even more important (and may be required, depending on where you live). Better safe than sorry. Call before you dig!
My buried gas line runs through the side yard. I got it marked before I started digging.
Out of an abundance of caution, I’m going to use the location of the buried gas line on my property as a good place to locate a path (rather than a flower bed that requires digging).
I’ll talk more about weed control in a future post, but when you are selecting a site (and deciding how big an area you want to plant), you should also be thinking about how you are going to manage weeds. I am planning to get mulch. But I have resigned myself to the fact that I may be doing some extra hand weeding this summer. It will be a good activity to get me out of the house in the evenings and on the weekends.
Stay tuned for more updates on this project!
This post was written by Amara Dunn, Biocontrol Specialist with the New York State Integrated Pest Management Program. All pictures in this post were taken by her.
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
This isn’t biocontrol, but it’s very important! Have you heard about the invasive spotted lanternfly? Do you want to learn where we are in our efforts to keep it out of New York, and to manage it if (and when) it does show up?
New York State Integrated Pest Management is hosting a meeting in Binghamton, NY on Thursday August 15 where you can get answers to these questions.
This conference has been approved for 7.5 Certified Nursery Landscape Professional credits, and 6 NYS Pesticide Recertification credits in the categories of 1a, 2, 3a, 6a, 9, 10, 22 and 25.
Mulching transplants planted in Spring 2018 was the most expensive establishment method, but these plots were looking pretty good a year later, even before we weeded.
By the end of our first field season, we had started using six different methods to establish wildflowers as habitat for beneficial insects (plus a weedy mowed control treatment). We also collected data on how much time and money we spent on establishment and how successful our weed management was. You can read about results from Year 1 in my post from last November.
But beneficial insect habitat establishment is not a one-year project. The establishment methods we started to implement in 2018 are ongoing, including periodic mowing of direct seeded plots, and hand-weeding of transplanted plots. We’ll keep track of how much time and money we invest in these plots in 2019, too.
Plots that were direct seeded in 2018 will be mowed this year to favor the perennial beneficial insect habitat plants over annual weeds. This plot was treated with alternating herbicide and tillage during Summer 2018, and wildflower seed was planted in Fall 2018; (A, left) plot before mowing, (B, right) same plot after mowing.Plots that were transplanted in 2018 will be hand weeded this year to help the perennial wildflowers and grasses out-compete weeds. This plot was transplanted in Spring 2018 into bare (not tilled) ground and no mulch was used; (A, left) plot before weeding, (B, right) same plot after weeding.
And we want to know whether these plots are actually attracting beneficial or pest insects. So, in 2019 we are starting “Phase II” of our beneficial insect habitat work. We want to know which and how many insects (and other arthropods, like spiders) are being attracted to each type of plot. We will also count insects in no habitat plots (weedy, mowed occasionally) and mowed grass plots in the middle of the Christmas tree field for comparison.
Insect collection began in early May, and we are using four different techniques:
Sweep net – This is what it sounds like. We “sweep” a net through the air above the ground to capture mostly flying insects, or those who may be resting on the plants.
Butterfly and moth count – We walk through the field, counting how many of each butterfly or moth species we see in each plot.
Pan traps – These are bright yellow and blue bowls filled with soapy water. One bowl of each color is placed in each plot for 2 days, then we collect the insects that have been attracted to the colorful bowls and were trapped in the soapy water. This method will help us count flying insects, especially bees and wasps.
Bright blue and yellow bowls filled with soapy water and weighed down with rocks will attract certain flying insects. By counting insects collected in these pan traps, we can learn which insects are spending time in each plot.
Pitfall traps – These are clear plastic 16-oz deli cups (like you might use for take-out food) that are sunk into the ground in each plot. Insects that crawl along the ground fall in. We will use this method to count mostly ground-dwelling insects.
A pitfall trap collects ground-dwelling insects. This one is protected by a rain cover. We didn’t want all the rain we’ve been getting this spring to overflow the traps and wash away the insects we caught!
I will write another blog post or two about this project during or at the end of this season. If you want to see more frequent updates, follow me on Twitter (@AmaraDunn). I’ll post weekly pictures of this project, including which beneficial insect habitat plants are blooming each week. You can also see lots of pictures from this project on Instagram (biocontrol.nysipm).
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
