Yard and Garden: August 2, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for August 2, 2019. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am. 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.

Guest Host: Dennis Ferraro, Extension Wildlife Specialist, UNL

1. The first question of the show was about pole green beans. They were planted in May and have been blooming but have not produced any beans yet. What is wrong with them?

A. This is likely due to the abnormal weather pattern we have seen this spring and summer. Make sure that the plants are mulched and watered evenly, as much as you can. Also, the warmer night temperatures will keep the beans from developing.

2. A caller has lilacs that are 2 feet tall. They have rust spots on the leaves. What is causing this?

A. This is likely due to a fungal disease. Make sure you are watering from the base of the plant and keep mulch around the plants. Fungicides can be used but if it is just on a few leaves, just pull those off and destroy them. It also is a little late to spray fungicides on the plants this year. At the end of the year clean up all the fallen leaves from around the plant to prevent re-infection next year.

3. This caller has turf that continually gets brown patch every year, it is only getting one hour of sunlight per day. What can be done to help reduce this problem?

A. Unfortunately, the turf isn’t growing well in this location. Turf is a full sun plant and needs at least 6-8 hours of full sun per day, not dappled light. In this location the turf will always have problems. It might be a good time to switch to another plant underneath the trees. Shade perennials or groundcovers could replace the turf and they would grow much better there. Sedges are another good choice that look very similar to the lawn but would tolerate the shade better.

4. What can be used for weeds in a driveway?

A. Roundup 365 would be a good option for this. It contains glyphosate as well as imazapic which lasts longer than the glyphosate alone. On the label it states to only apply once a year and to “spray until THOROUGHLY WET”, so for best results spray to this extent. Soil sterilants aren’t recommended because they often run off into adjacent plant material such as grass and kills it. You could also use pre-emergent herbicides in the spring to help with annual weeds. Always read and follow the label when using pesticides.

5. A caller has bagworms in his windbreak. What can be done for bagworms now?

A. It may be a little late in the year to treat chemically for bagworms. Once they get much larger than 1/2″ in length, their feeding is reduced and sprays are not as effective. Also, the majority of their damage is done for the year. If you decide not to spray, it would help to go out and pick as many of the bags off as you can and destroy them.

Sandbur, Rebekah D. Wallace, Univ of GA, Bugwood
Sandbur, Photo courtesy of Rebekah D. Wallace, University of Georgia, Bugwood.org

6. How do you control sandburs?

A. Sandburs are an annual grass, so using crabgrass pre-emergent herbicides in the spring will also kill germinating sandbur seeds. Also, sandburs are easily out-competed, so if you can get something else to grow in the area, the sandbur population will be reduced.

7. This caller has Japanese beetles on Linden trees. What can be done to control them? Will the trees die from this?

A. The trees should be fine next year and will leaf out fine. You can spray the trees now with Sevin or chlorothalonil. Next year, you can spray with these products after the bloom period or when the beetles first appear. Do NOT use a systemic insecticide on linden trees due to the high amount of pollinators that are found on lindens.

8. A caller has a problem with squirrels eating his sweet corn. What can be done to stop the squirrels?

A. For a small plot of corn, you can drape bird netting over the corn and use fishing weights to hold it down. From Control of Tree Squirrel Damage NebGuide “Wire mesh fences (no larger than ½-inch weave) topped with electrified wire or mesh enclosures may be practical for keeping squirrels out of small areas. Electrified wires are not recommended for use where there are children or pets. Little else can be done with squirrels in larger areas, other than re-moving the offending squirrels by cage trapping or shooting where safe and legal.”

9. This caller has an apple tree that is covered with Japanese Beetles. She sprayed Tempo on the tree, can she still use the apples?

A. No, fruit trees are not listed on the label. When using pesticides be sure that the plant you are spraying the pesticide on is on the label. With fruits and vegetables, watch the PHI (pre-harvest interval) to know how long to wait between application and harvest.

10. A caller has pin oaks and something seems to be eating the leaves. The leaves are dying and this is a young tree and he is trying to avoid using pesticides. What can be done?

A. This damage could be from grasshoppers or beetles, most of the damage seems to be happening at night so it could be chaffers that are active at night. Using a neem oil or insecticidal soap would work for these pests as an organic option.

11. This caller is having troubles with a groundhog. How can manage the groundhog?

A. Trapping works best for groundhogs. Put burlap over the cage because groundhogs are spooked easily. Use a half an apple or half an ear of corn for bait. Wire the cage open for a few days to allow the groundhog to take the bait and become more relaxed with the trap. Then, after a few days set the trap without wiring it open. Once you catch the groundhog, you cannot translocate it. It must be euthanized with a firearm if legal where you are or take it to animal control. Be sure to check local laws before controlling this groundhog. For more information, visit wildlife.unl.edu

12. A caller is trying to control his bagworms, what chemical can he use for bagworm control?

A. Tempo is a great choice, but sevin or any other general insecticide will work. It may be a little late in the year to treat chemically for bagworms. Once they get much larger than 1/2″ in length, their feeding is reduced and sprays are not as effective. Also, the majority of their damage is done for the year. If you are planning on still spraying, get it done very soon.

13. The last caller of the year called to say “Thank You!” He removed brome grass competition from around his trees, thanks to advice from the show, and now his trees are growing much better.

*Disclaimer ­- Reference to any specific brand named product does not constitute endorsement, recommendation, favoring or implied criticism if similar products are not mentioned by Nebraska Extension in Gage County.  Identifying specific pesticides are for the convenience of the reader and are generally most commonly available.  Always read and follow the pesticide label.

Yard and Garden: July 19, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for July 19, 2019. 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 2, 2019. 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: Jay Seaton, District Forester for the Lower Platte South NRD

blossom end rot zucchini
Blossom end rot on a developing zucchini

1. The first question of the show was regarding fruit development on zucchini. The fruits begin to develop and then one end begins to die. What is causing this?

A. This sounds like blossom end rot, it can happen in zucchini, tomatoes, peppers, watermelons, and others. Blossom end rot is when the end of your vegetable that is away from the plant rots and turns black. It occurs on the end of the vegetable that had the flower, hence the name blossom end rot. The cause of this disease is a calcium deficiency, but calcium is in the soil in sufficient quantity, uneven watering will reduce the ability of the plant to access this calcium. Calcium has to be dissolved in water for the plant to be able to obtain it from the soil. Adding calcium to your garden is not effective for managing this problem. Not all of your produce should be affected by this problem, they tend to grow out of these conditions later in the summer, so there is no need to treat your garden for blossom end rot. Maintain moisture and mulch to help with this disorder.

This caller also wondered why his pole beans are not producing yet. He shared the seed with a friend and that friend has harvested but he has not. Why is that?

A. This is likely an environmental issue. Give the plant a little more time to produce the beans. The friend’s garden would have a different microclimate from your garden it may have more sunlight or more heat radiating from a nearby building that your garden doesn’t have.

2. This caller has zucchini that is dying. They seem to have rotten roots when going to look at why they have died. She waters with a hose on trickle twice a week for 30 minutes each time. What is wrong with them?

A. This sounds like too much water is getting applied to the plants. Jay estimated that this was likely applying about 5 gallons of water per week, which is quite excessive. It would be better to use a soaker hose or measure the amount of water applied to the plants each time you let the hose trickle. Vegetable gardens only need about 1 inch of water per week.

3. A caller has pickling cucumbers that are growing good but as they grow one end of the cucumber becomes smaller than the other end. What would cause this?

A. This is likely due to heat stress. There isn’t much we can do to avoid damage from the hot weather. Make sure that the plants are mulched and they are receiving the correct amount of water.

4. This caller has tomato plants with brown leaves at the bottom of the plant. What is causing this?

A. This is likely a fungus. We have seen quite a bit of early blight this year already. Look for concentric rings in the brown spots on the leaves. If it is just a few leaves, pull those leaves off the plant and destroy them. Be sure to keep the plants mulched and water from the base of the plant rather than overhead irrigation to help reduce the spread of the disease.

japanese beetle JAK582
Japanese Beetle, Image from Jim Kalisch, Retired from UNL Entomology

5. What can be done about Japanese beetles? This caller said she was going to try traps and wondered about homemade traps.

A. Don’t use traps, they will attract more Japanese beetles than what you have in your landscape already. Spray all of the areas at the same time. She said one day she would spray the garden, the next a shrub, and the next a tree. If you avoid spraying in areas where they are commonly found, those other locations will become a safe haven for the beetles. Sevin is a good insecticide to use to control the beetles. Be sure to read and follow the label for spraying every 10-14 days and for the PHI, to know when it is safe to harvest again after spraying. Using grub control in the lawn can help. You can also go out in the evening when the beetles are grouped up to knock them into a bucket of soapy water to kill them.

6. This caller wants to know if they should hold back on fertilization of roses and garden now due to the heat?

A. If your plants look fine, don’t worry about fertilizing them right now. Avoid fertilizing the vegetable garden this time of the year. If the nitrogen level is too high around vegetable plants, the plants will grow large and beautiful but will not produce fruit because nitrogen is for leafy growth of the plant. I usually advise avoiding fertilization of the garden this late in the season.

7. The last caller of the day has a sweet potato vine with holes in the leaves. She saw a grasshopper the other day, would that be causing the problem?

A. This could be from grasshoppers, especially since you saw some on the plant. Use Sevin to treat for them. Make sure you spray the grassy ditches and roadsides as well, which is where grasshoppers are found more often.

She also has zucchini plants that have gray, translucent spots on the leaves. What would cause that?

A. She sent a picture to clarify the problem. It looked like a slight fungal disease. It is nothing that is too damaging to the plants. Copper fungicide could be used but I don’t think it is necessary. Good sanitation is key to controlling fungal diseases in the garden. Mulch the garden and avoid overhead irrigation during the season to help prevent splashing spores from the ground and from plant to plant. Remove the plants from the garden at the end of the season.

Yard and Garden: July 12, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for July 12, 2019. 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 2, 2019. 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: Sarah Browning, Extension Educator in Lancaster County

1. The first question of the show was about ivy growing on a garage. The caller had Japanese beetles earlier this year and sprayed with sevin. Now he is seeing a lot of flying insects, one looks like a lightning bug. What type of insect would this be and will they cause damage to his ivy?

A. They could be lightning bugs which will not harm your plants. Japanese beetles will come back, it would be best to keep spraying to ensure they stay away. You can use the sevin every 10-14 days or you can use a product containing Azadirachtin which has some repellent properties so it will help to keep the Japanese Beetles away longer.

2. A caller has a newly planted maple tree that has brown spots on the leaves. It looks like something is eating it but she can’t find any bugs. The spots look like brown strips with yellow around it. What is causing that?

A. This could be the tree drying up and getting heat stress. This tree was just planted this year so it isn’t established well and will dry out faster in this heat. She has been watering by hand and that isn’t getting the tree enough water. It would be better if she watered with a small sprinkler for about 45 minutes once a week.

3. This caller has a 40-year-old Ponderosa Pine that had diplodia tip blight that got so bad she removed the tree. There is a blue spruce nearby, would that tree be getting the tip blight as well? The spruce has tips of the branches that are bent over and the needles are all bunched together. What would cause that?

A. Diplodia tip blight will not affect spruces. It is a problem for pines, mostly Austrian and Ponderosa. This is not what is affecting the spruce. The damage on the spruce sounds like sirococcus shoot blight. It is past the treatment time for this disease, but it won’t kill your tree in one season. In the spring spruces can be sprayed with chlorothalonil when the shoots are 1/2-2 inches in length and repeated every 3-4 weeks if frequent rains occur.

Blossom end rot on tomato
Blossom end rot on a tomato

4. What can be done for blossom end rot in tomatoes?

A.  Blossom end rot is when the end of your vegetable that is away from the plant rots and turns black. It occurs on the end of the vegetable that had the flower, hence the name blossom end rot. The cause of this disease is a calcium deficiency, but calcium is in the soil in sufficient quantity, uneven watering will reduce the ability of the plant to access this calcium. Calcium has to be dissolved in water for the plant to be able to obtain it from the soil. Adding calcium to your garden is not effective for managing this problem. Not all of your produce should be affected by this problem, they tend to grow out of these conditions later in the summer, so there is no need to treat your garden for blossom end rot. Maintain moisture and mulch to help with this disorder.

5. A caller wants to know what to plant for a fall garden and when it should be planted.

A. Fall gardens can be very beneficial and work better than spring gardens due to the cooler temperatures and higher amounts of moisture in the fall. Start transplants indoors now for things like Brussels sprouts, broccoli, cabbage, and cauliflower. The average first frost date for most of Southeast Nebraska is October 6-16, this comes from data from the High Plains Regional Climate Center. You can use the first frost date to figure out when to plant fall crops. Use the first frost date as a starting point, count backward the number of days to harvest listed on the packet of seeds and add a 10 day fall factor because the plants will mature slower due to the cooler weather. Plants or seeds should be planted in late July to early August. You can also plant your second crop of warm season vegetables now if you haven’t yet to get a longer harvest period and possibly avoid problems with insects and diseases during their peak time.

6. This caller has a rose bush with something eating the leaves off it. What would cause this and how can it be controlled?

A. This could be from a couple of different issues. Japanese beetles will feed on the leaves of roses and cause the leaf to look like lace with little leaf left besides the veins. Rose slugs can do some damage to roses but it looks worse than it is and the feeding should be nearing completion for the year. If you aren’t seeing the insects, it could be rose chafers that feed at night. It could also be from a disease such as black spot. Look for a product that contains an insecticide and fungicide to help with any of these problems. A liquid would be better than a dust.

7. A caller has brown spots in his lawn. What is the problem and how can he fix it?

A. This could be due to either brown spot or dollar spot. These two diseases are quite common this year due to the wet spring and early summer conditions we faced. In a home lawn it isn’t usually necessary to use a fungicides because the fungi don’t kill the lawn and they are sporadic from year to year. It will fade soon and the grass will green back up. These diseases don’t affect the crown of the grass plant so it will easily grow out of it after a few mowings. Through discussion, we learned that his underground sprinkler system waters the lawn from 1am-6am. It was suggested that he do an irrigation audit and move the time for watering forward to 4am-10am. Watering overnight keeps the lawn wet in the cooler, dark environment which is great for disease development.

8. The final caller of the show have sugar maples that leafed out well this year but now the leaves are turning brown and dropping off the tree. What is causing that?

A. This could be from anthracnose, a fungal disease of the tree. It can infect the leaves and cause them to fall from the tree. It could also be from not watering enough now that the rains have reduced or from scorch. Be sure to water the tree and look for damage on the trunk or girdling roots. Look for borer holes as well and treat with imidacloprid if holes are present. It is most likely from an environmental condition, which we cannot change. The tree should be fine.

Attack of the Beetles

JB Damage
Damage from Japanese Beetles

This year, like always, we are facing insect issues in our lawns and gardens. It is important to remember that not all insects are bad, in fact the majority of all insects are beneficial in some way. However, when they are found in large populations or damage our plants, or both, we get concerned.

 

Soldier Beetles

Soldier Beetle
Soldier Beetle, Photo from Soni Cochran, Lancaster County Extension Assistant

Soldier beetles are common this year. These are the yellow beetles found in large quantities throughout the area this year. They are often confused with fireflies because they are both beetles without hardened elytra, like many other beetles, and they are similar in appearance. The soldier beetle we are seeing is golden in color with a black spot on each wing on the back. They are commonly found around Linden trees as well as many other flowers. There is no need to control soldier beetles because they are great pollinators and will not harm our plants or us.

Japanese Beetles

Japanese Beetle, 7-16 Acreage
Japanese beetle adult on the left side and grub on the right side, photos from Jim Kalisch, UNL Entomology

Japanese beetles have been more of a problem for southeast Nebraska over the past couple of years than they had been in the past. This is an invasive insect from Japan. Japanese beetles are problematic insects as both larvae and adults. The larvae are a type of white grub which feed on the roots of our grass, causing large brown dead spots in the turf that are easily lifted up like a rug from the floor.

Adult Japanese beetles are 7/16 inch-long, metallic green beetles. The elytra, or wing coverings, are copper. As adults, Japanese beetles feed on over 300 species of plants including trees, shrubs, fruits, vegetables, field crops, weeds, and other ornamental plant species. Some of their favorite food plants are roses, lindens, and grapes. Adult beetles feed on the foliage, flowers, and fruits of these plants. They feed on the upper surface of the leaves and cause a skeletonized pattern to the leaf where the veins of the leaf are often left behind but the rest of the leaf is chewed away. In some cases, they will consume the entire leaf. This can stress the plants, and in high populations of beetles can even kill the plant.

Grubs can be controlled with chlorantraniliprole or imidacloprid in June. Adults can be controlled with systemic insecticides such as imidacloprid or dinotefuron around Mother’s Day to give the products time to get throughout the trees and shrubs being treated. Currently, no systemic insecticides can be used on Lindens though, due to the damage to pollinators. Tempo and Bayer Advanced Lawn & Garden Multi-Insect Killer (cyfluthrin), Ortho Bug B Gone (bifenthrin), or Sevin (carbaryl) would be a few other options that can be used on Lindens and others. These options will only work for about 2 weeks so they may need to be reapplied.

Blister Beetles

blister beetles, K. Jarvi
Black and gray blister beetles, Photos by Keith Jarvi, Emeritus Extension Educator

Blister beetles were a real problem in our vegetable gardens last year, and they are back. Blister beetles are ½ inch long, powdery gray colored beetles with black antennae. They can feed on our tomato plants as well as some other vegetable crops. They can damage our plants, but they are also beneficial because they feed on grasshopper eggs. If you find them in your garden, you can treat with general insecticides such as sevin or eight. Be careful handling these beetles, some people develop blisters after handling them.

What’s that green beetle…

Green Beetles Blog post

All plants are wonderful. However, it is highly unlikely to find a plant that has absolutely no insect problems. This year we have been seeing a couple of unusual beetles wreaking havoc in our vegetable gardens and they can be found on our trees and shrubs as well. Japanese Beetles and Green June Beetles have been more problematic in southeastern Nebraska this year than most other years.

Japanese beetles are an invasive insect from Japan, where it is not a major pest due to the natural predators found there. This pest was first found in the United States in a New Jersey nursery in 1916 and was likely introduced in infested iris bulbs from Japan.  Since this initial introduction, Japanese beetle populations have steadily expanded westward.

Japanese beetles are problematic insects as both larvae and adults. The larvae are one of the four most common types of white grubs found in Nebraska. As a white grub, larvae feed on the roots of our grass, causing large brown dead spots in the turf that are easily lifted up like a rug from the floor. Adult Japanese beetles are 7/16 inch-long, metallic green beetles. The elytra, or wing coverings, are copper. These beetles can be distinguished from similar looking beetles by the six tufts of white hair along both sides of the abdomen. As adults, Japanese beetles feed on over 300 species of plants including trees, shrubs, fruits, vegetables, field crops, weeds, and other ornamental plant species. Some of their favorite food plants are roses, lindens, and grapes amongst others. Adult beetles feed on the foliage, flowers, and fruits of these plants. They feed on the upper surface of the leaves and cause a skeletonized pattern to the leaf where the veins of the leaf are often left behind but the rest of the leaf is chewed away. In some cases, they will consume the entire leaf. This can stress the plants, and in high populations of beetles can even kill the plant.

Green June Bug vs JB

Green June beetles are often being found this year as opposed to other years. They are very large, usually more than one-inch in length. They are dull green with some brownish coloration to the elytra and a tan border along the margins of their elytra, which are the hard wing coverings on a beetle. Green June Beetles will feed on ripe fruits and vegetables like tomatoes, corn, and grapes. They will feed on the fruits and the leaves of the plants and as an immature, they are also a white grub species.

These 2 green beetles can be controlled through multiple methods. As larvae, they are best controlled with insecticides applied to the lawn in the months of May, June, and July. There are many different options available including the most common grub control, Merit which contains imidacloprid. Pesticides can be used on the adults in plants, however, be sure to avoid use of pesticides directly on the flowers of these plants to avoid harming pollinators. Imidacloprid, sevin, eight, or other general insecticides can be used on trees and shrubs to control the beetles. In low adult populations, you can hand pick the beetles off of plants and throw them into a bucket of soapy water to kill them and not harm any pollinators.

Yard and Garden: July 7, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for July 7, 2017. 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 July 28, 2017. 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: Bob Henrickson, Assistant Director of the Nebraska Statewide Arboretum

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1.The first caller of the day has 10 lilacs growing in a lawn which are now getting a gray film on the leaves. What is causing this problem?

A. This is due to powdery mildew. This is a common problem on lilacs. Lilacs often get this disease if they are planted too closely together reducing air flow or if they are planted in heavy shade. If these plants are not growing in either of these environments, it is likely due to the wet spring we saw this year. Fortunately, this disease is not very damaging to the plants and there is no need to treat for it.

2. A caller has many American elm trees growing in his pasture that seem to suddenly be dying this year after the leaves turn brown and curl up on the branches.

A. Unfortunately, this is likely due to Dutch Elm Disease, which is still present and active in Nebraska. Many of our trees can grow for a few years and then the trees get large enough and conditions become conducive, that it shows up and kills the trees fairly quickly. The only management strategy is to remove and destroy the infected trees to reduce the spread to other trees.

chicory, Joseph M Ditomaso, Univ of CA-Davis, bugwood
Photo of Chicory from Joseph M DiTomaso, University of California-Davis, Bugwood.org

3. What are the blue flowers blooming along the roadside now and can the seed be purchased somewhere?

A. That is chicory, a non-native plant often used in roadside mixes. The seed can be found in some roadside mixes or at local seed sources.

4. A caller has a sunset maple with leaves that are curling and falling off the tree. What could be wrong with the tree?

A. This could be due to herbicide drift. Trees stressed by herbicide drift will often lose their leaves and push new growth. As long as they are producing new leaves that are not curled, the tree will likely be fine. However, many years of damage from herbicide drift can cause more stress and even possibly death.

5. This caller has voles in their yard. How can these be controlled?

A. Snap mouse traps can be placed in the runs perpendicular to the runs. These traps will catch and kill the mice. Here is a guide on vole control

6. A caller has a copper-colored beetle in her elm trees that are causing holes in the leaves. What would this be and how can they be controlled?

A. This could be a Japanese Beetle, an invasive insect from Japan. It is a green beetle with copper-colored wings. These beetles need to be controlled as they can do a lot of damage quickly. They chew on the leaves causing a skeletonization of the leaves as they leave behind the leaf veins. They can be treated with a insecticide containing imidacloprid.

7. A caller has a grass that grows in her lawn. The grass grows in a large circle about the size of a dinner plate and tends to turn brown in any kind of drought when the rest of the lawn does fine, but thrives in higher moisture content. What would this be and how can she make her lawn look more uniform?

A. This could be a cool season weedy grass species. They are often found in our lawns growing in a large circle. I would recommend spot spraying the areas of this different type of grass and then reseeding. This would be best done this fall. Be sure to spray the spot while it is still green and actively growing and use a product such as glyphosate. Overseed the areas in September.

8. This caller has hollyhocks with brown spots on the leaves. What could this be from?

A. This is likely due to hollyhock rust, a common fungus of hollyhocks. Remove the leaves as they develop the disease and destroy the leaves and plant parts removed in the fall cleanup. Fungicides can be used if necessary, such as a liquid copper fungicide.

9. A caller has peach trees that have developed some insects in the peaches making them unedible. What can be done about that?

A. There are a lot of different insects that feed on the fruits of peaches. The oriental fruit moth is one. For any fruit tree, either deal with some insect and disease damages throughout the years or keep your trees on a spray program. Spray every 10-14 days throughout the growing season with an Orchard fruit tree spray that contains two insecticides and a fungicide. Avoid spraying during full bloom. For more information, visit food.unl.edu/local-food-production

10. This caller has a sycamore that has shed some leaves and is now shedding bark. What is wrong with the tree?

A. The shedding bark could be normal. Sycamore trees have an exfoliating bark that is normal to give it the camouflage bark appearance. It may have been hit earlier this spring with anthracnose causing the leaves to drop. Anthracnose is a minor, but common, disease of sycamore trees. It is more prevalent in wet weather, such as this spring. There is no control for it, but the tree should be fine.

11. A caller has been trying to seed grass where a septic tank was and can’t get it to grow. What is wrong?

A. At this point in the year, it would be best to wait until fall to plant grass seed due to the heat, humidity, and lack of rain. However, if you have been trying in the spring and fall and can’t get it to grow, I would recommend getting a soil test done of the soil where this problem is occurring. This will help tell if the soil has other problems because of the septic tank or what was put back into the hole. It was also determined that this is an area around a large tree with a great deal of shade, if the area is too shady for grass, try a groundcover or a carex species that will grow better in more shade.

12. When is the best time to spray for bagworms?

A. Now would be a good time since the bags have emerged. Make sure you spray before the bags are 1 inch in length for best control. You can use any general insecticide for controlling bagworms such as sevin, eight, bifenthrin, tempo, or Bt can be used for a safer control method. Bt will not harm bees and other beneficial insects.

13. A caller has a Norway Spruce that is 8 feet tall. It has been drying up since this spring and looks like it is dying. The tree has been planted here for 5-6 years and is watering slowly every 2 weeks since the trees were planted. What is causing it to die?

A. This could be due to overwatering. The roots of the trees need to breathe in between waterings. If the caller is filling a moat around the trees with water every 2 weeks for this many years, it would be excessive.

14. The final caller of the day wondered if the yard could be sprayed to help with chiggers? He also wondered when the time was to use sedgehammer on the lawn?

A. Nothing can be sprayed on the lawn to entirely help with chiggers. The best defense against chiggers would be to use insect repellent that contains DEET and to wear light colored clothing. Sedgehammer is best used before June 21st or the longest day of the year to help reduce the populations of nutsedge for next year. However, it can still be used this late in the year to kill what is in the lawn this year.

Yard and Garden: July 1, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for July 1, 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: Bob Henrickson, Assistant Director of the Nebraska Statewide Arboretum

1. The first caller of the day wants to use weed fabric and white rocks around the foundation of his house. Is this a good idea?

A. This can be done, but as horticulturists, Bob and I are always for more greenspace and less rocks. The weed fabric will work for a short time but often weeds will germinate through or on top of the fabric and it is hard to remove or change after the fabric is in. A good option would be to plant shrubs and perennials in there to help hide the foundation to the siding. Wood chip mulches will help with weed control around the plants.

2. A caller has a problem with ground squirrels in their lawn.

A. a trap can be built to control ground squirrels. The Internet Center for Wildlife Damage Management has a good guide for 13-lined ground squirrels.

3. A caller has bees in their sand play area. What can be done about it?

A. The best control for this would be to cover the sandbox so the bees cannot burrow into the sand to build their nest. If this can’t be done, you can sprinkle a little sevin in the holes where the bees go to nest. This is not the best option if you have kids playing in the sand because the chemical would not be safe for that. Otherwise, spraying the sandbox with water or soapy water will deter and possibly kill the bees.

4. This caller has a bald cypress tree that had lacebugs last spring. This year it hasn’t leafed out on the branches, most of the leaves are on the trunk. What can be done for this tree?

A. Removal and replacement. When a tree only leafs out on the trunk there is some reason that the flow of water and nutrients is not going through the whole tree. This could be due to borers or some type of root issue. Even with trees that are 8 years old, they could have had a root injury or been planted too deeply or had a stem girdling root that is now causing death of the tree. There is no cure for this at this point in the trees life.

5. A caller has a new lawn that they are trying to rejuvenate. What would the process be?

A. They are watering 2 times a week with a sprinkler for a couple of hours at a time, this should be sufficient. Stick with what you have been doing and don’t abruptly reduce it. Fertilize with the holidays: Arbor Day, Memorial Day, Labor Day, Halloween. So at this point don’t fertilize until the fall. Fertilizing in hot weather can cause more stress or leaf burn. For weed control, use crabgrass pre-emergent in the spring with the Arbor Day fertilization and use 2,4-D in the fall.

6. What to do when planting a tree that is badly rootbound?

A. It is hard to fix a tree when the roots are already rootbound. Once they begin to grow in a circular pattern, they will continue to do that for life, and damage doesn’t always show up until the tree is 10-15 years old. It is best to look at the roots before purchasing to choose a smaller tree with healthy roots. Also, when you get it home, remove the excess topsoil from the top of the rootball to ensure that it gets planted at the correct depth.

7. An email question came in to ask what to do for stump removal where they cut down and removed some shrubs?

A. Keep cutting the suckers off as they regrow and mulch the area if you just want to be rid of the plants. If you want to replant into the area, you will have to remove the stumps by digging them out or using a stump grinder to grind them out. Do not use Tordon in this area as it is against label regulations and it will not speed up the process and it can kill other desirable plants.

8. A caller has a firethorn plant with spidermites that they see on the plant every year and it causes them to loose many leaves each year. What can be done for them?

A. A strong stream of water will often work for spidermites. If the population is too high you will have to use insecticidal soaps. If this is an annual occurrence you may want to remove these shrubs and replace them with something that isn’t so problematic in this area.

9. What do you do for sandburs?

A. Sandburs are an annual grass, so crabgrass pre-emergent herbicides in the spring will help reduce the population by stopping germination. At this point in the year you can use a post-emergent grass herbicide such as Drive. Keep the area mowed to reduce the seed production for next year.

10. A caller has honeysuckle that is now invasive through his yard. What can be done to eliminate the honeysuckle plants? Also, is hickory a good tree for Nebraska? Why don’t we see hickory trees planted more?

A. Continual cutting of the honeysuckle will eventually kill it. You may want to try to dig up the plant to help reduce the problem. You can also treat the stump with roundup and/or 2,4-D. Use 2,4-D products in the spring or fall, it is now too hot to use this product without possible damage to desirable plants. Hickory is a great tree for Nebraska, it is just underutilized. Good hickory tree choices for Nebraska include Shagbark Hickory, Bitternut, and King Nut. Shagbark Hickory was the Great Plants of the Great Plains Tree of the Year Selection in 2011.

 

Japanese Beetle, 7-16 Acreage
Japanese Beetle adult on the left and immature on the right. Photos by Jim Kalisch, UNL Entomology.

11. A walk-in listener brought in a green beetle to be identified.

A. This is a Japanese Beetle. It is identified by the green metallic color, gold elytra, and white spots along the sides of the abdomen. This is an invasive insect from Japan that feeds on over 300 species of trees and shrubs, it favors roses and plants in the rose family. It will cause a skeletonization of the leaves as the adult feeds. As immatures they are a white grub that feeds on the roots of our turf. Management of white grubs in the turf will reduce the population. As adults, they can be controlled with general insecticides such as sevin, eight, bifenthrin, malation, or others. Don’t use insecticides on the flowers or flower buds to help with pollinator populations.

12. The final question of the day was from an email asking what chemicals do you use for bagworms?

A. Bagworms can be controlled with Bt, spinosad, sevin, eight, malathion, or tempo. The treatments need to be completed before the bags are smaller than 1/2 inch in length. You can also remove bags as they are seen and throw them into a bucket of soapy water to kill them without pesticides if you can reach them all.