Tag Archives: plant disease

Upcoming Events: Online Gardening Classes

Looking for an online gardening class?

Check out these classes being offered by Cornell Cooperative Extensions around the state. 

Click on the topic to see what classes are being offered.

Container Gardening

Six heads of large heads of green and red lettuce growing in a raised garden bedGrowing Edibles in Containers

Monday, April 27, 2020
4:00 PM – 5:30 PM
Cornell Cooperative Extension
Broome County

A cluster of cherry tomatoes growing on a tomato plant wet with the morning dew.Crops in Pots – Growing Vegetables in Containers

Monday, April 27, 2020
4:00 PM – 5:30 PM
Cornell Cooperative Extension
Rockland County

A short wooden tub set next to a tree overflowing with plants: a tall grass with red leaves, a bright green plant with white veins and a dark purple plant spilling over the edge.Creative Container Gardening

Wednesday, May 27, 2020
6:00 PM – 8:00 PM
Cornell Cooperative Extension
Tompkins County

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Composting Classes

Two hands holding finished compostMagic Compost

Tuesday, April 28, 2020
10:00 AM – 11:00 AM
Cornell Cooperative Extension
Suffolk County

Pile of kitchen scraps, mostly peels of various fruits and vegetables, spead out on top of a compost pileComposting Basics

Wednesday, April 29, 2020
7:00 PM – 8:00 PM
Cornell Cooperative Extension
Oneida County

Three large compost bins, one made of wire fencing and two made of palletsComposting

Friday, May 8, 2020
12:00 PM – 12:45 PM
Cornell Cooperative Extension
Schenectady County

Full Wooden Compost BinHome Composting

Monday, May 11, 2020
1:00 PM – 2:00 PM
Cornell Cooperative Extension
Jefferson County

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Cut Flowers

A garden patch of magenta, orange and yellow zinniasGrowing Cut Flowers

Wednesday, April 29, 2020
6:00 PM – 8:00 PM
Cornell Cooperative Extension
Tompkins County

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Edible Landscaping

A vegetable garden with a combination of cabbage surrounded by small yellow and orange flowers and dark purple leafy greensEdible Landscaping

Monday, May 4, 2020
1:00 PM – 2:00 PM
Cornell Cooperative Extension
Jefferson County

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Fruit

Two small light green fruits (pawpaws) growing of a branchGrowing Unusual Fruits

Wednesday, May 20, 2020
6:00 PM – 8:00 PM
Cornell Cooperative Extension
Tompkins County

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Native Plants

Swamp Milkweed - Lots of small pink flowersNative Plants

Wednesday, April 29, 2020
4:00 PM – 5:30 PM
Cornell Cooperative Extension
Rockland County

Small Tree covered with Pink FlowersUsing Native Plants in the Landscape

Tuesday, May 5, 2020
8:30 AM – 12:30 PM
Cornell Cooperative Extension
Nassau County

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No-Till Gardening

Light purple clover flower against a background of green leavesNo-Till Gardening Techniques

Wednesday, May 6, 2020
6:00 PM – 8:00 PM
Cornell Cooperative Extension
Tompkins County

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Pest Management

Yellow beetle with black spotsGarden Pest and Disease Management

Tuesday, April 28, 2020
5:00 PM – 6:00 PM
Cornell Cooperative Extension
Lewis County

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Pollinators

A butterfly on a pink zinniaAttracting Pollinators to Your Garden

Tuesday, April 28, 2020
6:00 PM – 7:00 PM
Cornell Cooperative Extension
Schenectady County

Bumble bee on a pink flowerPlant a Pollinator Paradise

Saturdays, May 2 & 9, 2020
9:30 AM – 11:00 AM
Cornell Cooperative Extension
Putnam County

Close-up of a leaf cutting bee on a yellow flowerPollinator Gardens

Monday, May 18, 2020
1:00 PM – 2:00 PM
Cornell Cooperative Extension
Jefferson County

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Pruning

Turquoise handled pruning shears surrounded by flower petalsPruning Shrubs

Monday, April 27, 2020
6:30 PM – 7:30 PM
Cornell Cooperative Extension
Tompkins County

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Soil

A garden trowel stuck in the the soil of a raised garden bedAll the Dirt on Soil

Wednesday, May 6, 2020
2:00 PM – 3:00 PM
Cornell Cooperative Extension
Chemung County

Light purple clover flower against a background of green leavesNo-Till Gardening Techniques

Wednesday, May 6, 2020
6:00 PM – 8:00 PM
Cornell Cooperative Extension
Tompkins County

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Ticks

Blacklegged Tick Don’t Get Ticked NY

Tuesday, May 5, 2020
6:00 PM – 7:30 PM
Cornell Cooperative Extension
Schenectady County

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Vegetable Gardening Classes

Six heads of large heads of green and red lettuce growing in a raised garden bedGrowing Edibles in Containers

Monday, April 27, 2020
4:00 PM – 5:30 PM
Cornell Cooperative Extension
Broome County

A cluster of cherry tomatoes growing on a tomato plant wet with the morning dew.Crops in Pots – Growing Vegetables in Containers

Monday, April 27, 2020
4:00 PM – 5:30 PM
Cornell Cooperative Extension
Rockland County

A hand holding bunch of freshly picked radishes Three Steps to a Successful Vegetable Garden

Wednesday, April 29, 2020
2:00 PM – 2:30 PM
Cornell Cooperative Extension
Chemung County

Pile of cucumbers, a red, yellow and green pepper, green onions, tomatoes, a bunch of parsley and a sprig of rosemaryVegetable Gardening

Friday, May 1, 2020
12:00 PM – 1:00 PM
Cornell Cooperative Extension
Schenectady County

Wicker basket full of lettuce, tomatoes, peppers, beets, turnips,onions and a sprig of mintVegetable Gardening 101

Saturday, May 2, 2020
10:00 AM – 12:30 PM
Cornell Cooperative Extension
Tompkins County

Light purple clover flower against a background of green leavesNo-Till Gardening Techniques

Wednesday, May 6, 2020
6:00 PM – 8:00 PM
Cornell Cooperative Extension
Tompkins County

Basket over flowing with vegetables - tomatoes, carrots, peppers, broccoliGrowing Vegetables and Small Fruits

Wednesday, May 6, 2020
7:00 PM – 8:00 PM
Cornell Cooperative Extension
Oneida County

A cucurbit seedling showing the two cotyledons and the first true leaf just starting to unfold.Planting a Vegetable Garden

Monday, May 11, 2020
2:00 PM – 3:00 PM
Cornell Cooperative Extension
Chemung County

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Wildlife Management

A baby deer (fawn) munching on a clover in a lawnWildlife Management

Thursday, April 30, 2020
4:00 PM – 5:30 PM
Cornell Cooperative Extension
Rockland County

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What’s in Bloom? – April 2020

Even though most of the trees are still bare and must of us awoke to snow on the ground this weekend, spring has arrived and with it are some of the most beautiful blooms of the year.

Spring Flowering Bulbs

Pink and purple hyacinth flowers
Hyacinthus orientalis
Clump of white daffodils with bright orange centers and yellow daffodils
Daffodils (Narcissus spp.)

The crocuses have all but faded, but the daffodils continue to bloom, brightening up the drab landscape with their cheery yellows and oranges.   They have recently been joined by the hyacinths.  With their overpowering fragrance, these flowers add to springs color palette with their cool colors of pink and purple.

Grape Hyacinth - cones of tightly packed purple flowers

You may have noticed some small purple flowers known as grape hyacinths.   Not a true hyacinth,  the inflorescence of this flower is a cone of small purple flowers that almost looks like a miniature clump of grapes.

White daffodiles with bright yellow center
Daffodil ‘Ice Follies‘

If you want to bring some spring cheer inside (highly recommended), it is best to give daffodils their own vase as their stems secrete a substance that is harmful to other flowers.

 

Spring Ephemerals

White and purple flowers growing out of a patch of soil
A mixture of the white spring ephemeral bloodroot (Sanguinaria canadensis) and the purple spring bulb green anemone (Anemone blanda).
Clump of small flowers with five purple petals a light yellow center
Hepatica nobilis

One of the great joys of spring is the appearance of spring ephemerals.  These native plants grow in wooded areas and only have a short time to flower before the trees above them leaf out and block their sunlight.  When you are walking through wooded areas in the spring, make sure you watch your feet or might step on the delicate flowers of the bloodroot or the hepatica.

Other Spring Blooms

Clusters of cascading pink flowers
Andromeda (Pieris japonica)
Small purple and magenta flowers in a mass of green leaves with white spots
Lungwort (Pulmaria spp.)

From the showy flowers of the andromeda bush to the subtle flowers of the lungwort, the more time you spend out side the more flowers you’ll notice.

Weeds – It’s all in the eye of the beholder.

Dandelion with a bright yellow flower growing in the crack between two pavers
Dandelion (Taraxacum officinale)

Many spring flowering plants are considered weeds.  You may think that dandelion in your lawn is unsightly, but the bees beg to differ.  Dandelions are an important source of pollen and nectar for bees in the early spring as are other spring flowering ‘weeds’ like purple deadnettle and henbit.

What about Fungus?

Bright orange sphere with orange tentecales attached to the needles of an evergreen tree
Cedar-Apple Rust Gall (Gymnosporangium juniperi-virginianae)

Now fungi aren’t plants, so they don’t have flowers, but they can add color to the landscape.  In the spring cedar-apple rust galls that overwintered on juniper become more noticeable as they produce gelatinous tendrils that release spores  into the air.  Some of these spores will find their way to apple trees where they can cause problems by infecting the leaves and the fruit of the tree.


Happy Spring!

Spring bouquet of bright yellow daffodils and forsythia, purple grape hyacunth, white andromeda, and buds of a pink cherry treeThanks to all of the Master Gardener Volunteers who provided their thoughts and photos for this post!

What kind of insect is destroying my plants?

Biting / Chewing vs. Piercing / Sucking

By Susan Ndiaye, Community Horticulture Educator

This article appeared in the July 2019 Issue of Gardening in Orange County. Click here to subscribe!

Insects can cause a lot of damage to your plants.  Determining what insect is causing damage to your plant is key to developing an effective management strategy.  The first step is to examine the damage.

Biting/Chewing Insects

A leaf covered with holes and a small grasshopper
Chewing damage

Biting/chewing insects create holes in plant leaves.  The size and shape of these holes varies by  insect.  The three most common types of insects with biting/chewing mouthparts you may find in your garden are: grasshoppers, butterfly/moth larvae, and beetles (adults and larvae).

 Grasshoppers

Two mating diffrentail grasshoppers, the male sitting on top of the female
Differential grasshoppers (Melanoplus differentialis)

Grasshoppers are a sporadic pest and rarely cause substantial damage to garden plants.  During dry years when other plants dry out, grasshoppers may seek refuge and food in your lush green garden. Unfortunately, because grasshoppers are highly mobile they are difficult to manage.  If you have an ongoing problem with grasshoppers, you can reduce populations, by fall tillage as grasshoppers overwinter as eggs laid in the soil.

Imported Cabbageworm (Pieris rapae)

Imported cabbageworm larvae, a velvety green caterpillar with a faint yellow strip down the miidle of the back, hanging out on a leaf
Imported cabbageworm larvae
Imported Cabbageworm adult, a white butterfly with three black spots on the forewings perched on a rasberry bloom
Imported cabbageworm adult

Those beautiful white butterflies you see fluttering around your garden, may seem innocuous, but their larvae, the imported cabbageworm, can cause extensive damage to plants in the brassica family also known as cole crops.  These plants include broccoli, cabbage, Brussel sprouts, collards, kale, radishes, and turnips.  The caterpillar is bright green with a yellow stripe down the center of its back.  They start out chewing little holes in the leaves of the plants, but eventually consume the entire leaf leaving only the midrib behind.

A very holey head of cabbage a result of feeding by the imported cabbageworm
Imported cabbageworm damage on cabbage

To monitor for these pests, look for dark green frass or poop near feeding areas.  Once you discover a population of imported cabbageworm, depending on how numerous they are you can hand pick them off your plant.  The use of Bt (Bacillus thuringensis), a microbial insecticide is also highly effective on younger caterpillars.  This particular pest spends the winter in the pupal stage, so to prevent future infestations you can eliminate overwintering sites in your garden by removing plant debris.

Stripped and Spotted Cucumber Beetles (Acalymma vittatum and Diabrotica undecimpunctata howardi)

A single stripped cucumber beetle, black and yellow vertical striped with an orange thorax, a black head and black legs and filiform antennae, on the orange flesh of a pumpkin
Stripped cucumber beetle

Although they are called cucumber beetles, these insects feed on much more than cucumbers.  The stripped cucumber beetle prefers plants in the cucurbit family (squash, pumpkins, melons, etc.) feeding on leaves, flowers, stems and fruits.  They can be especially detrimental to young seedlings.

Spotted cucumber beetle, a yellow beetle with black spotts, a back head, legs and filiform antenna
Spotted cucumber beetle / Southern corn rootworm

The spotted cucumber beetle is more of a generalist and feeds on cucurbits as well as beans, tomatoes, and ornamentals. The larvae of this beetle can do substantial damage on the roots of corn plants hence its other name, the southern corn rootworm.

 

A cucumber plant sith bacterial wilt, there is a scetion of health plant and a two foot vine with shriveled brown leaves
Bacterial wilt of a  cucumber plant

Cucumber beetles vector or transmit bacterial wilt (Erwinia tracheiphila), a common disease in cucurbits in which bacteria clog up the vascular system of the plant preventing the flow of water and causing the plant to wilt and eventually die.

One way to protect your plants from cucumber beetles is by using row cover.  This can be put on at planting and kept on until female flowers appear, then it must be removed to allow for pollination.

Sucking/Piercing Insects

Squash bug damage on a squash plant - edges of the leaf are brown with a yellow line between the brown area and the green center of the leaf
Squash bug damage on a squash plant

Sucking/piercing insects can cause of variety of symptoms including leaf malformation and leaf discoloration. The most common types of insects with sucking/piercing mouthparts are from the Order Hemiptera, also known as the “true bugs”.  This order of insects contains, stink bugs, squash bugs, cicadas, leaf hoppers, scale, aphids and many more.

Brown marmorated stink bug (Halyomorpha halys)

A brown shield shapped bug with white and black marmoration on the edge of the wings
Brown marmorated stink bug adult

Many people are familiar with this invasive species because the adults invade their home every fall looking for a nice warm place to spend the winter.  Although it can be an unwelcome house guest it also can cause major damage on fruits and vegetables.  Some of the brown marmorated stink bug’s favorite snacks include apples, peppers, beans, tomatoes, and sweet corn.

About 20 orange and black colored brown marmorated stink bug nymphs clustered around their egg mass
Brown marmorated stink bug 1st instar nymphs clustered around an egg mass

Controlling the brown marmorated stink bug can be quite difficult because they are highly mobile, feed on a large variety of plants, and adults are highly resistant to insecticides.  Monitoring for these pests is the best way to start.  Bunches of about 28 eggs are laid on the underside of leaves and should be removed and destroyed if found.  When the eggs hatch the 1st instar nymphs cluster around the egg mass making them an easy target for removal.  The bugs usually drop down when startled, so for hand removal, you can knock them into a container of soapy water.

Lots of research is being done to develop effective management strategies for brown marmorated stink bug.  One of the most promising avenues of research is on biological control.  A stingerless wasp known as the Samurai Wasp (Trissolcus japonicas) destroys 60-90% of brown marmorated stink bug egg masses in its native range in Asia.  This tiny wasp has found its way to the United States and as of 2018 has been found in twelve states, including New York.  Research is now being done to determine the effectiveness of rearing and releasing this tiny parasitoid.  Check out this video about brown marmorated stink bug and the samurai wasp.

Potato Leafhopper (Empoasca fabae)

Potatoe leaf hopper adult on a leaf
Potato leaf hopper adult
Neon green leaf hopper nymph on the underside of a leaf
Potato leaf hopper nymph

Despite their name, potato leaf hoppers feed on over 200 hundred different kinds of plants including potatoes, snap beans, cucumbers, pumpkins, egg plants, rhubarb, squash and sweet potatoes.  The nymphs are neon green and are usually found crawling around on the underside of leaves.  The adults only reach ⅛ inch in length. They are pale green and wedge shaped and fly away when disturbed.

hopper burn on bean leaves, edges of leaves are yellowing, entire leaf is distorted
Hopper burn on bean leaves

These little pests do not overwinter in our area, but instead overwinter down south and the adults are brought up each year by the winds arriving in late-May / early-June.  Although small, a few individuals can cause hopper burn on your plants.  Hopper burn reduces yield and is characterized by chlorosis, or yellowing, of the leaf edges.  Eventually these leaves begin to curl and turn brown.

It is easiest to combat these pest as flightless nymphs using insecticidal soaps or horticultural oils on the undersides of leaves.  Dusting plants with diatomaceous earth can also help deter these pesky bugs.

Squash Bug (Anasa tristis)

Squah bug nymphs, green with black legs
Squash bug nymphs

Squash bugs are pests of all cucurbits, but prefer squash (summer and winter varieties) and pumpkins.  Adults are a little over a ½ inch long and are dark brownish while nymphs are black, pale green or gray with black legs.  These insects feed mainly on the leaves and the stems of squash plants, but can also feed on the fruits.  Initially they cause a stippling on the leaves, but after heavy feeding the leaves begin to look tattered.

Squash bug adult laying eggs
Squash bug adult laying eggs

Squash bugs overwinter as adults, so at the end of the season cleaning up plant debris and mulch will remove overwintering sites.  Eggs are bronze colored and usually laid in clumps on the underside of leaves.  Removing and destroying egg masses can help keep squash bug numbers down.  Adults and nymphs are known to hide in mulch around the base of the plants, laying down a board or piece of cardboard will provide a hiding place for these bugs.  You can then remove the shelter and destroy all the bugs underneath it.  There are also some cultivars of both summer and winter squash that are resistant to squash bugs.


Of course there are lots of non-insect pests that can wreak havoc on your garden as well and whose damage can sometimes be confused with insect damage.  Snails and slugs have rasping mouth parts that create holes in plant leaves much like insects that have biting/chewing mouth parts. Spider mites having piercing/sucking mouth parts that cause stippling on plant leaves like the “true bugs”.

So as you try to determine what is causing damage to your plants keep in mind that different kinds of insects cause different kinds of damage and that determining the cause is essential to developing a solution.

Note: Pesticide recommendations are not a substitute for pesticide labeling.  Remember to read the label before applying any pesticide.  The label is the law!

Helpful References

Vegetable Insect-Mite Pests

https://extension.umd.edu/hgic/topics/vegetable-insect-mite-pests

Brown Marmorated Stink Bug

https://www.stopbmsb.org/stopBMSB/assets/File/BMSB-in-Vegetables-English.pdf

https://extension.umd.edu/hgic/topics/stink-bugs-vegetables

 Grasshoppers

https://extension.umd.edu/learn/grasshoppers-life-cycle-and-control

Imported Cabbageworm

https://extension.umd.edu/hgic/topics/imported-cabbageworm-vegetables

http://idl.entomology.cornell.edu/wp-content/uploads/Imported-Cabbageworm.pdf

Potato Leafhoppers

https://extension.umd.edu/hgic/topics/potato-leafhopper-vegetables

Squash Bugs

https://extension.umd.edu/hgic/topics/squash-bug-vegetables

Striped and Spotted Cucumber Beetles 

https://extension.umd.edu/hgic/topics/cucumber-beetles-spotted-or-striped-vegetables