Yard and Garden: August 3, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for August 3, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am this was the final episode for 2018. It can be found again next spring on kutt995.com for online listening. If you enjoy reading my Q&A from the show each week, take my quick survey at: go.unl.edu/yardandgarden18 and be entered to win a free tree diagnostic book.

Guest Hosts: Kevin Christiansen, Horticulture Instructor at SCC Beatrice & Evan Alderman, Turfgrass Management and Horticulture Instructor at SCC Beatrice

1. The first caller of the day has a windbreak that has elms growing in it. How can he kill the elms and not harm the windbreak trees?

A. In this situation you need to use a herbicide that will kill the elms but will not be translocated through the roots into the surrounding windbreak trees. Tordon should NOT be used in this location. A good option would be either glyphosate, Roundup, or a 2,4-D product. Use these 2 products as a stump treatment on the tree just after cutting the tree off.

2. A caller has cucumbers that are blooming but are not producing any fruit yet. Why are the cucumber not producing? This caller also wondered how to control puncturevine?

A. The cucumbers could be due to no female flowers, if all the flowers are male, they will not produce any fruits. Sometimes our plants start with just male flowers and the females will come in later. It could also be due to low pollinators around the plants. If not many bees or beetles or other insects are found around the plants, they cannot be pollinated and may need to be hand pollinated. Hand pollination can be done by running a cotton swab through all of the blooms, this would move pollen from male flowers to female flowers. Puncturevine can be controlled with a 2,4-D product in the fall. Apply the 2,4-D in mid-September and in mid-October.

3. When should you transplant surprise lilies?

A. Surprise lillies can be transplanted or divided just after the flower dies back in the fall.

4. This caller has foxtail in the vegetable garden. Can anything be sprayed in the garden to control the foxtail?

A. There is nothing that can be sprayed over a garden to control foxtail and not harm the garden plants. The best option would be to use preen in the spring and summer to stop the germination of annual weeds such as foxtail. Be sure to use the preen that is labeled for use in a vegetable garden and wait until after all seeds planted have germinated. Mulch would help suppress the weeds in the garden as well. Grass clippings, straw, or other organic mulches will help keep the weeds down to help your vegetable plants grow better.

5. A caller was looking for assistance choosing fruit trees for his acreage. He also has rust on his fruit trees and wants to know how to manage it.

A. There is a great NebGuide on Fruit Tree Cultivars for Nebraska. For rust, this is not the correct time to treat for it. You can spray your trees in the spring with a liquid copper fungicide. For more on care and pest control of your fruit trees, visit: https://food.unl.edu/local-food-production

6. This caller has a windbreak of Red Cedars that are losing limbs. The trees are 100 years old and 30 feet tall. What is wrong with them?

A. This could be due to old age. It may be a good idea to start a new row of trees on the inside of the old row.

7. A caller has nutsedge in his lawn. What can he spray it with and can he still spray it?

A. Sedgehammer is the best control for nutsedge. It can still be sprayed now, however more control will be achieved if applied in the beginning of June, prior to the first day of summer. If sprayed before June 21st, nutlet production will be reduced, thereby reducing the population for the following year.

2014-10-06 15.27.18

Tree planting in the fall

8. This caller wants to know when the best time is to transplant an oak tree?

A. Fall or Spring are both good times to transplant a tree.

9. How do you control cattails and water lilies in a pond?

A. Rodeo is the glyphosate product that is labeled for use in water and it can be used on both of these weeds.

10. How can you control crabgrass and nutsedge in a lawn

A. Quinclorac can be used now for both of these weeds. Or use a pre-emergent herbicide in the spring and again in June for the crabgrass and sedgehammer for the nutsedge in June. Tenacity is another product that should work on both of these weeds.

11. A caller wants to know why we should worry about getting rid of cattails and water lilies in a pond?

A. Weeds in a pond can strangle the waterways or destroy habitat for fish. Some plant life along the edge of the pond can be beneficial, but too much can be a detriment.

12. This caller has lilies with caterpillars in the stem. What are those and how can they be destroyed?

A. This is likely a cutworm. Sevin or eight or Bt applied at the base of the plant can help kill these pests before they damage your plants.

13. When is the proper time to apply a winter fertilizer on a lawn?

A. Fall fertilizer can be applied in late August to mid September and the winter fertilizer can be applied in the middle to late October. It is no longer recommended to apply the winter fertilizer in November as previously recommended.

14. A walk-in listener has a weed they need identified and they need to know how to control it?

A. This is a weed called nimblewill. It is a warm-season grassy weed. It can be treated either with Roundup or Tenacity. If you use Roundup and reseed, apply the roundup now, while the nimblewill is still green and then overseed in a couple of weeks through the end of September.

15. This caller has spaghetti squash that was looking great and then one day it just died. What caused it to die and how can the other plants be protected?

A. This is likely due to squash vine borer. You can use sevin or eight to protect your plants from the squash vine borer. Be sure to apply it at the base of the plant where the plant comes out of the ground. These chemicals will need to be reapplied every 10-14 days throughout the growing season to protect the plants. Otherwise, you can wrap the base of the plant in aluminum foil to prevent the borer from getting into the plant.

16. A caller has watermelons with yellowing leaves. This has happened to his plants 3 years in a row now, he does rotate the crops in the garden. This damage starts at the base of the plants and will eventually kill the whole vine. He has mulch on the garden and waters slowly with a hose for 2 hours at a time. What is causing this problem? Also, when do you transplant iris?

A. This looks to be alternaria leaf spot. He is doing many things to prevent this disease already with mulch and his watering practices. It might be beneficial to try a liquid copper fungicide this year and next year as soon as the symptoms begin. Iris can be transplanted in the fall, September or October would be best.

17. A walk-in listener has a tree they want identified and they want to know why it keeps suckering and what they can do with the suckers?

A. This is a silver maple tree, they are prone to suckering. Suckers should be just cut off as they grow to reduce the amount of energy they take from the main tree. Do not treat the suckers with anything as that could injure or kill the main tree because the suckers are growing off the main tree roots.

18. This caller wants to know why their pepper plants are not growing well?

A.The peppers are planted too closely to a black walnut tree and will not grow well in that location. Black walnut trees produce juglone, which is basically a naturally produced weed killer. Certain plants are more sensitive to juglone, tomatoes and peppers are quite sensitive. The garden should be moved to at least 50 feet from the black walnut of the plants should be grown in a container or raised bed to avoid problems with the juglone.

19. The final caller of the year has hostas planted in a rock garden and they are not growing, they are still small like they were just planted there.

A. The rock garden may be too hot for the hostas and the rocks do not provide any nutrients back to the plants. It might be best to switch to a wood chip mulch to help reduce the heat and add some nutrients and organic matter to the soil.

2015-07-30 16.59.55

Bindweed

This caller also wanted to know what to do to kill the bindweed growing in her Iris beds?

A. Among other plants it is best to use the “glove of death” which is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Glyphosate and rub those fingers along the stem and leaves of the bindweed to kill it. Basically, the idea is to keep it from flowering and producing more seed, hand pulling will help keep new seed from being deposited into the garden which can be viable for up to 60 years.

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Problems in our Gardens

Vegetable garden 1

Growing my own produce in my backyard is one of my favorite things of summer! Vegetable gardens are great exercise, give you an excuse to eat healthier, and are very enjoyable but they can be a lot of work as well. There are always problems in our vegetable gardens, usually they are temporary or easily fixed.

Production Issues

The weather this year has not been favorable to our plants. We have been facing aborting flowers of our plants due to heat and low pollination. Now, even though our plants are producing, the tomatoes are not ripening up. The hot weather contributes to this as well. When temperatures are consistently as hot as they have been lately, tomatoes may develop but they don’t turn red. According to Purdue University, the pigments responsible for the red color in our tomatoes are not produced when the temperatures exceed 85 degrees. So, when we see long stretches of very hot weather, our tomatoes will not ripen. Be patient, they will ripen eventually when the very hot temperatures recede.

Blossom end rot is also starting to show up in our gardens. Blossom end rot is when the blossom end (the end not attached to the plant) begins to rot. This is due to uneven watering, which is seen quite often in the early part of the growing season where we see stretches of drought surrounded by 2-3 inch rains. Again, this should fade through the season as the plants grow through it. You can still eat the other end of the tomato and discard the rotted end or give your plants time, the next harvest should be better.

Cracks may also start to appear in our tomatoes due to the weather. With uneven watering comes cracks in our developing fruits. Our fruits can grow rapidly due to rapid intake of water which can build up pressure in developing tomatoes. Cracks typically appear on the top of the tomato, often in rings, and are not harmful to us if we eat them. Check for insects that may have gotten into the cracks of our fruits before eating.

2018-07-18-20-05-36.jpg

Grass clippings are applied as mulch around zucchini and cucumbers

Using Mulch

Mulch is a great way to combat these issues. Many of our problems in our gardens stem from uneven watering or plants that got too hot and dry to deal with the stresses of the environment. Mulch can keep moisture around the plants and keep the roots cooler to help with these issues as well as reduce competition from weeds. Grass clippings make a great mulch. If the grass has been treated with any herbicides this season, look at the label to know if or when it can be used as a mulch. Grass clippings break down quickly so they should be reapplied often. Straw is also a great mulch for the garden and it wouldn’t need to be reapplied as often. These types of mulch can then be tilled into your garden at the end of the season or before next season to add nutrients back into your soil.

squash vine borer damagePests

Squash bugs and squash vine borer are seen in our gardens every year. Squash bugs cause yellow speckling on the leaves and feeding damage on the fruits. You may also see rusty colored eggs on the underside of the leaves that can be removed and destroyed. Squash Vine Borer causes rapid death and wilting of the plants. These pests feed on plants in the cucurbit family, which includes zucchini, squash, cantaloupe, watermelon, cucumbers, pumpkins, gourds, etc. Squash vine borer can be controlled by wrapping the stem of your plants with aluminum foil to stop the females from laying their eggs on your plants. Other controls include Carbaryl (Sevin), Permethrin (Eight), or bifenthrin (Bifen). This will need to be reapplied often through the growing season. It is best to switch between at least two of these products to avoid resistance from developing.  Always follow the label recommended rates and follow the pre-harvest interval listed on the label when harvesting fruits and vegetables after using chemicals.  Spray the undersides of the leaves and the base of the plant thoroughly.  All sprays should be done later in the evening to avoid damage to bees and other pollinators.

Yard and Garden: August 5, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for August 5, 2016. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 5, 2016. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Graham Herbst, Community Forester Specialist with the Nebraska Forest Service

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/9b24 and be entered to win a free plant book or some free UNL gifts.

1. The first question of the day was a walk-in client wondering what the weird structures in his yard were?

A. These would be fungal formations. The one that popped open is a puffball and the other is a type of mushroom. Neither of these are edible, they are both poisonous. They will develop in a yard from decaying roots of old or removed trees. They can be removed manually if you would like or they will go away on their own.

2016-08-05 10.14.05

Puffball on the left, Mushroom on the right

2. A caller has a small tree that is leaning that looks like a palm tree, what is it and why is it leaning?

A. After visiting the home after the show, it was determined that the tree was a sumac. It is leaning because that is the growth habit of a sumac. They tend to form a colony and lean every direction for sunlight.

3. A caller has a zucchini plant that just all of a sudden started dying off. Is this plant just done for the year or can something else be wrong with it?

A. This is probably due to squash vine borer. There is no way to fix the problem once it has gotten to the point of wilt and death. When you remove the plant, cut open the stalk to see the borer caterpillar. For the remaining plants use sevin, eight, or bifenthrin at the base of the plants to reduce the chances of those plants getting the borer as well. You can also wrap the base of the plant with aluminum foil or a toilet paper tube to protect it from borers laying eggs to bore into the plants.

4. A caller has cedar trees that have pine cone structures all over them that are killing the trees. What are these and how can they be controlled?

A. Those would be bagworms. At this time of the year it is too late to control them as their feeding has greatly reduced and possibly stopped for the year. Once they are in their bag the sprays cannot penetrate the bags to get to them so there is no need to spray now. Pick off and destroy all the bags you can get to and next spring watch for them sooner to spray at the correct time of the year.

Bagworm4

Bagworm

5. With bagworms, will sevin work for spraying them?

A. Yes. Sevin, eight, bifenthrin, tempo, malathion, or bT are all good insecticides to use when the bagworms are actively feeding.

6. A caller has wild cucumber growing on trees. How can this be controlled?

A. This weed has shallow roots and will pull out easily. You can treat with a herbicide, but not as a spray because that would harm or even kill the tree it is growing on. You can paint roundup on the leaves to help control it.

7. This caller has a mature maple tree that has mushrooms growing in the center of it. Can it survive?

A. It is best to manage the trees shape throughout the life of the tree to help it from having to have large branches removed. At this point there is no way to fix the hole and decay that have already begun. If the tree is in a location that it will not hit structures or people it can be left up longer, but it would be best to have a certified arborist come take a look at it to determine if the tree is safe to stand or needs to be removed.

8. A caller has a tree that the roots were exposed during work on the house nearby and then the roots were covered back up. Now, there are a lot of tree suckers coming up throughout the lawn. Can Tordon be used to control these?

A. Tordon is not labeled for use in a landscape setting. Also, using any type of insecticide on the suckers could harm or even kill the main tree. Since these suckers are all growing in the lawn, it would be best to just continually mow them off. The suckers appeared because the tree was stressed from the construction around the roots. Sucker stop can be used to slow the growth of the suckers but not completely eliminate them.

9. An email question was asked how to control locusts that are taking over a pasture?

A. Grazon is a good choice for pastures as a full foliage treatment during June. You can cut the stump and do a basal treatment anytime. Another choice would include Dicamba or a Trimec product that contains dicamba.

10. Another email question came in with a cottonwood tree that has brown tips on the leaves and lots of ants on the tree. Are the ants causing the problem? Can this be controlled?

A. The brown tips could be from sunscald which is due to the heat and drought we have faced lately. Aphids are probably also present on the tree which would bring the ants in to feed on their honeydew excretions. The ants are not harmful to the tree. The aphids are not causing much of a problem. Control measures are not necessary. Mulch the tree and water it to help with sunscald.

11. A caller from Iowa has hostas that were variegated in the leaves for the past 20+ years and now the leaves are solid green. What is causing this?

A. This is called reversion. The plant is a hybrid or cultivar that has reverted back to the original plant or parent plant with solid green leaves. It will not turn back into the variegated form.

12. A caller wanted to know why windbreaks and trees along creeks are being removed?

A. Sometimes the trees get old and start to become a hazard after they die. It also allows for more farming areas. These windbreaks are beneficial to wildlife, insects, and soil microbes and to help reduce water pollution from pesticide and fertilizer runoff.

13. The last caller of the 2016 season wanted to know when to transplant clematis, iris, peony, spirea, and general perennials?

A. all of these can be transplanted in the fall. Wait until mid to late September before doing this to get through the hot, dry weather. Could be done in the spring with some of these as well, but fall would be great.

Thanks for all of the great questions on the show and for reading the blog posts! I look forward to another great season of Yard and Garden Live in 2017!! Keep reading my blog for other great updates on keeping your yards and gardens “Green and Growing”!

Yard and Garden: July 15, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for July 15, 2016. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 5, 2016. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Julie Albrecht, Professor in Health and Nutrition Science

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/9b24 and be entered to win a free plant book or some free UNL gifts.

1. The first caller of the day wanted to know how to control corn earworm in his sweet corn?

A. The best option would be for next year, because at this stage it is too late to control them if you are already harvesting. It would be best to choose a resistant variety so chemicals won’t be necessary. You can spray for the earworm, but it should only be done twice per season with carbaryl (Sevin) and it should be sprayed on the silks where the eggs are. There will not be much control this late in the season since the earworms are already there.

2. A caller has green beans that are blooming but they are not setting on. What would cause this?

A. This could be due to poor pollination due to low amount of insect activity in the high temperatures. If pollination doesn’t occur soon, you could hand pollinate the plants by using a q-tip to touch the pollen of male flowers and then touch the stigma of the female flowers. It could also be that the flowers present are all male flowers and then it will just take time for the female flowers to appear.

3. This caller noticed that they have a lot of grasshoppers in their flowers. What can they do to control them?

A. Any general insecticide will work on grasshoppers. Sevin, eight, tempo, malathion, etc will work on flowers. Also be sure to spray the ditches and roadsides where grasshoppers are common. If grasshoppers are in the vegetable garden only use chemicals labeled for use in the vegetable garden and watch the PHI for when you are able to harvest after applying chemicals.

4. A caller has acorn squash in his garden. Recently, one of the plants all of a sudden died, the leaves turned brown and it got wilty. He is watering all of the plants the same and only one plant looks like this. What would cause that?

A. This is probably due to squash vine borer. There is no way to fix the problem once it has gotten to the point of wilt and death. When you remove the plant, cut open the stalk to see the borer caterpillar. For the remaining plants use sevin, eight, or bifenthrin at the base of the plants to reduce the chances of those plants getting the borer as well. You can also wrap the base of the plant with aluminum foil or a toilet paper tube to protect it from borers laying eggs to bore into the plants.

squash vine borer damage

5. How long should you boil green beans when processing them and do they need to be cut to certain lengths when processing?

A. Green beans can be used whole or cut to any desired length. For processing, boil in a pressure canner at 11 pounds pressure for a dial gauge or 10 pounds pressure for a weighted gauge canner. They should be boiled for 20 minutes for pint jars and 25 minutes for quart jars. If you are blanching the green beans for freezing, they should be boiled for 3 minutes and then immediately placed in cold water prior to placing in freezer bags for freezer storage. For more information on processing foods, visit the National Center for Home Food Preservation at: http://nchfp.uga.edu/

6. Why is it not safe to can in an oven?

A. The jars can explode and that can cause the glass on the door of the oven to explode as well. There are no recommendations regarding length of time to can in the oven because there is no way to determine how hot the center of the jar is. It is important to ensure that all of the contents of the jar get to the correct temperature for proper, safe canning practices.

7. A caller is growing tomatoes in feed barrels, the leaves are curled up. Is this due to a soil nutrient issue or what could be causing this, he waters every other day with a hose until the water runs out the drainage holes in the barrels?

A. This could be due to physiological leaf curl. This condition often appears as spring weather gives way to hot, dry summer conditions. Plants often put on large amounts of foliage growth in the spring and they don’t have enough roots to provide sufficient water to support the plant as the weather gets hotter and drier. Plants cope with this water issue by rolling their leaves. The older leaves are usually affected first. Leaves roll upward toward the center mid-vein, without any deformation or twisting. Plant leaves may recover and unroll if the stress is alleviated. Harvest yield is not affected.

8. This caller has heard an old saying that you should put your corn into a brown paper sack before putting it into the freezer for freezing corn on the cob. Is this true?

A. This wouldn’t do anything for the corn. Just make sure that you use a freezer bag for anything you freeze and that you only put it one layer deep until it has all frozen through to get it to freeze faster and help the shelf life of the product.

9. A caller wanted to know how to tell when peaches are ripe?

A. The red coloration is not a good sign for peaches now due to new peach varieties with a lot of red coloration in the skin color. It is best to just pick a few when they are getting close to being mature and try the flavor. You don’t want to pick the fruits before they are ripe as the sugar content will be low. When the base color has turned from green to full yellow they should be mature.

10. The final caller of the day has a tree that he transplanted from a construction site. When it was moved, the roots were slightly damaged and the top of the tree broke out. It lost all of its leaves when it was planted in the new location in late May, but now has new growth on the ends of the branches. Will this tree survive?

A. Give it time, the fact that there is growth on the ends of the branches is hopeful. The tree would have lost apical dominance when it lost the top of the tree. Use a wooden dowel and some masking tape to try to start a new leader. The root damage may not be evident on the tree for 10-15 years so you won’t know for a while if it will survive from the root damage. Keep watering the tree every other day for 20-30 minutes during this year and add a mulch ring that is 2-3 inches deep and 2-3 feet wide around the trunk of the tree.

 

Problems in the Garden

Now that summer is in full swing, our gardens should be growing well now. It is at this time of the year when we always tend to see many different diseases and environmental conditions on our vegetable garden plants.

blossom end rot zucchini

A zucchini developing with blossom end rot

One of the most common problems we see early in the growing season is blossom end rot. This is an environmental condition where the end of the fruit that is not attached to the plant begins to rot away. It starts as a flat, dry, sunken brown rot on the blossom end of the fruits. Gray mold can occur in this rotten spot of the fruit, as it progresses. Blossom end rot is caused by a calcium deficiency while producing fruit. In Nebraska, there is rarely a lack of calcium in the soil, but calcium needs to be dissolved in water to be absorbed into the plant, so, it often occurs in conditions of dry soil. Blossom end rot can occur in tomatoes, peppers, cucumbers, zucchini, or watermelons.

Drought stress, low daytime humidity, high temperatures, and rapid vine growth favor blossom end rot. Applying calcium to the soil or to the plant is not beneficial. It is best to just maintain consistently moist but not saturated soil. It will also help to use organic mulch near the base of plants to keep the soils moist. Often the first ripe fruits are affected and later produce is fine. Remove infected fruits at the beginning of the season and later ripening fruits should not be affected.

Scorch is another problem we often see in the summer months, especially when the temperatures range as high as it has been recently and rain is scarce. Currently scorch has been found on bean plants. When scorch appears on our plants the edges of the leaves will turn brown and papery. Wilting and leaf scorch can be reduced with regular watering during prolonged dry periods. Mulching around the base of plants will hold moisture in the soil.

Squash bugs and squash vine borer are seen in our gardens every year. With squash bugs, we will see yellow speckling on the leaves and feeding damage can appear on the fruits. You may also see rusty colored eggs on the underside of the leaves that can be removed and destroyed. With Squash Vine Borer, rapid death and wilting of the plants will occur, once they are found in our plants, there is no cure.. These pests feed on plants in the cucurbit family, which includes zucchini, squash, cantaloupe, watermelon, cucumbers, pumpkins, gourds, etc. Squash vine borer can be controlled by wrapping the stem of your plants with aluminum foil or a toilet paper or paper towel tube to stop the females from laying their eggs on your plants. Other controls include Carbaryl (Sevin), Permethrin (Eight), or bifenthrin (Bifen), or Bt for the squash vine borer. This will need to be reapplied every 10-14 days throughout the growing season. It is best to switch between at least two of these products to avoid resistance from developing. Always follow the label recommended rates and follow the pre-harvest interval listed on the label when harvesting fruits and vegetables after using chemicals. Spray the undersides of the leaves and the base of the plant thoroughly. All sprays should be done later in the evening to avoid damage to bees and other pollinators.

The information for this article came from Nebraska Extension’s Hort Update. This is a monthly news column covering seasonal information for Nebraska’s green industry professionals. It is produced monthly throughout the year by Nebraska Extension Educators from across the state. You can subscribe to this newsletter by going to hortupdate.unl.edu and selecting “subscribe” from the top tabs. You can also get there from the Gage County Horticulture Page from gage.unl.edu

Where do insects go in the winter?

Photo by Jan Hygnstrom, UNL Department of Agronomy & Horticulture

Photo by Jan Hygnstrom, UNL Department of Agronomy & Horticulture

With winter on its way and a few freezes behind us, it leaves us thankful that the mosquitos and other insects have finally quit bugging us for the winter months. But, where do insects go in the winter? Do they all just die? How do they always come right back to my yard, garden, and home next spring? Some insects head south for the winter, others overwinter in the garden, some spend the winter in cracks and crevices outside, and others come indoors to join us in a heated home for the winter.

Many of our ‘snowbirds’ or insects that move south for the winter are the lepidopterans, the insect order that contains butterflies, skippers, and moths. Some of the snowbirds include armyworm, corn earworm (also known as tomato fruitworm) and striped and spotted cucumber beetles. Since these insects do not overwinter in the garden, sanitation is not considered a control method for them.

Many insects overwinter in the garden so cleaning up and destroying plant debris can reduce their numbers. Reducing the population of insect pests limits the amount of damage they cause and provides more control options. Insects that overwinter on plant debris in the garden include cabbageworm, cabbage loopers, and squash bugs. The cabbage caterpillars overwinter as pupae inside cocoons attached to plant debris, usually the host plant. Squash bugs spend the winter as adults hiding in plant debris. This is why it is a best management practice to clean up the garden in the fall and not leave the plants in the garden to harbor insects over the winter months. Some insects will even spend the winter on weeds near the garden. Fall sanitation not only includes cleaning up or tilling under vegetable debris in the garden, but control of nearby weeds as well.

Squash bug-NH-pic monkey

Some of the insects that overwinter in the garden do so in the soil. These insects would include the adults of Colorado potato beetles, the eggs of grasshoppers, and the pupae of squash vine borers and onion maggots. Fall tillage of soil reduces these insects by exposing the insects to colder temperatures. Removing plant debris removes an insulating layer that also protects insects from extreme temperatures.

squash vine borer damage

When cleaning up plant debris, the general recommendation is to not add insect infested plants, diseased plant debris, or weed seeds to home compost piles. Most plant diseases and weed seeds, as well as some insects, are destroyed during composting when temperatures in the pile center reach 140° to 150°F. However, in many home compost piles, it is difficult to mix materials thoroughly enough to bring all waste to the center where it will be exposed to these temperatures.

It is often asked if insecticides applied to bare soil in fall will kill overwintering insects. The answer is not very often, if at all. Overwintering insects are often in the pupal or egg stage where they are protected from insecticides. Applying insecticides to the soil to try and control overwintering insects is not a responsible or effective use of a pesticide.

Many other insects come into our homes during the winter months to avoid freezing temperatures outside. Boxelder bugs, multicolored Asian ladybeetles, and stink bugs move inside in the fall and then leave in the spring. These insects survive the winter in our homes and other buildings. These insects can find places to survive outdoors under leaf litter and in other plant debris, but they are much more comfortable in our homes, as we are. They do not do any damage in our homes and should be vacuumed up or smashed when they are found in our homes.

Center photo by S. Cochran, Lancaster County Extension

Center photo by S. Cochran, Lancaster County Extension

This article comes from an article written by Kelly Feehan, Extension Educator in Platte County, Nebraska.