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.
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.
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 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.
This is the Q&A for the Yard and Garden show for July 13, 2018. 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 3, 2018. 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, Horticulture Program Coordinator for the Nebraska Statewide Arboretum
1. The first caller of the day has a bug zapper that was recently emptied. The zapper contained quite a few of these small, brown, bean seed-shaped insects. What would this insect be?
A. Based on this description, it could be June bugs. These smaller, copper colored beetles are common right now and they are attracted to lights at night. If you have a lot of June bugs, you may want to pay close attention to your lawn and any possible brown spots in it. The immature stage of June bugs are white grubs that feed on the roots of our turf.
2. A caller has a climbing rose that is 8-10 years old and it was recently cut down to about 15 inches tall, against the homeowners wishes. Will this plant survive?
A. This isn’t the ideal time to prune a rose, but it should be fine since prior to the pruning it was in very good condition. Make sure to keep the rose well-watered and keep a layer of mulch around it to keep it healthy during this time of heat as the rose will try to push new growth. Water it with 1 inch of water per week unless natural rainfall provides that. Keep the mulch 2-3 inches deep.
3. This caller has an elm tree that has a hole in the base of the tree that goes in about 1 foot deep. Will the tree be ok?
A. A picture was requested for this tree to determine the severity of the hole. This could be due to many different factors including a crown rot, root rot, or other type of root damage. The hole is not very large, but because it is a foot deep, there is a concern for the strength and stability of the tree. Keep an eye on the hole, if it gets larger or if the canopy starts to thin, it would be a concern that would need to be removed before it falls on something.
4. A caller has a black spot on the bottom of his tomatoes. What is causing this and can it be cured?
A. This is blossom end rot, it is where the blossom end (or the end of the tomato farthest from the plant) rots. It is due to a calcium deficiency due to uneven watering. The calcium is in the soil, but uneven watering makes it unavailable to the plant. Mulch will help keep the soil at a uniform moisture level to help protect plants from this disorder. Blossom end rot is a short-term problem in our vegetable crops. It tends to only affect the plant for a the first couple of harvests of the year and then the plant grows out of it. You can cut the black end off of the fruit and eat the rest.
5. This caller has a tropical hibiscus that she has moved outdoors for the summer. This hibiscus was looking fine but now some of the leaves are turning yellow. She waters every other day and it is on a wood patio on the south side of her home. What is causing this yellow color?
A. This could be heat stress due to the fact that this plant is in a location on the south side that gets very hot. She also should test the soil with her finger prior to watering to be sure to not overwater. If the soil is dry, water. If the soil is still wet, wait longer before watering again. This could also be due to spidermites. You can test for spidermites by placing a sheet of white paper below a few of the leaves and tapping on the leaves. If a few pieces of pepper seem to be moving on the paper, that is spidermites. If it is spidermites, the plant can be sprayed with a strong spray of water to knock the mites off and kill them or you can use Eight (permethrin) on it.
6. A walk-in listener brought in a plant that he needs identified. It is growing like a shrub with orange and red berries and it is spreading rapidly. What is it?
A. This is a plant called Tatarian Honeysuckle, it is a weedy species. It is spread rapidly by birds. Cut it off now before it becomes more established. Treat the stumps with Roundup or Brush Killer.
7. Does 2,4-D work on sandburs?
A. No, sandburs are a summer annual grass like crabgrass. Using a pre-emergent herbicide in the spring for crabgrass will control sandburs as well. If you didn’t use a pre-emergent in the spring, Roundup would work on sandburs but 2,4-D will not be very effective.
8. This caller has chokeberries that are about 4-5 years old and starting to set on. How do you know know when they are mature for harvesting?
A. At this point of the year, there should be clusters of small green fruits setting on the shrubs. The berries will turn dark purple in color when they are mature. There is a large harvesting window for chokeberries and the birds don’t come to this plant until after clearing the berries off of more preferred plant species.
9. A caller has sunflowers that were planted from seed and they have been coming back. The plants are similar to other sunflower plants seen around town but the flowers are much smaller than neighbors’ flowers. Are there different types of sunflowers?
A. There are a lot of different varieties that would influence the size of the flowers. Sunflowers are annual plants, so if they are coming back each year, they are coming back from seed. Sunflowers may not be true to seed so the type of flower may have changed over time or from year to year.
10. This caller wondered if the caller from question #7 may have been referring to puncturevine as they are commonly confused?
A. These plants do commonly get confused because they both produce a seedhead that sticks to your clothes or shoes. They are both annual plants as well. However, puncturevine is a broadleaf while the sandburs are grasses. A 2,4-D product will work to control puncturevine, but the pre-bloom stage is going to be most effective.
11. The final call of the day has bugs flying around their tomato plants and eating the tops of the fruits. What is that?
A. After seeing a photo of the damage to the fruits, it was determined that this is due to the tomato fruitworm. Tomato fruitworms can be controlled with sevin or eight. If there are insects flying around the plants as well, that is likely something different such as Japanese beetles. It is possible, and likely, that this caller has multiple insect issues. However, both of these pests will be controlled if he sprays for one, they are both affected by the same pesticides.
This is the Q&A for the Yard and Garden show for July 6, 2018. 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 3, 2018. 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: Dennis Ferraro, Wildlife Specialist from UNL
1. The first caller of the day wants to know if borers from ash trees can get into his walnut trees?
A. Some native borers can be a problem in both ash and walnut trees, such as the redheaded ash borer which is a common borer in many of our trees in Nebraska. When the Emerald Ash Borer gets to southeast Nebraska, it will not be able to. EAB is a pest in Ash trees only.
He also wanted to know how to move woodchucks and not kill them?
A. Live trapping will work for woodchucks. Use cucumbers or corn to bait them and wire the trap open for a few days before actually activating the trap because woodchucks are very cautious and will not be trapped the first time or 2 into the trap. The woodchuck can then be relocated to within 100 yards of the trapped location. State regulations prohibit relocation farther than 100 yards. It would also work to change their nesting location. This woodchuck is found under a building, so if you can chase it out during the day then pack the hole tightly with road gravel will prevent them from coming back. For more information, visit the UNL Wildlife website on Woodchucks.
2. A caller has heard that bull snakes will keep rattle snakes away. Is this true?
A. These 2 types of snakes do get along but bull snakes are more aggressive hunters and can out-compete rattle snakes. Because of this, rattle snakes usually relocate to find food.
3. This caller has tomatoes with bumps along the stem of the plant. What is wrong with the plant?
A. There is nothing wrong with tomatoes that develop bumps along the stem. These are aerial roots which are common.
4. A caller has a white powdery substance on her peony plants. What causes this and how can it be controlled?
A. This is most likely powdery mildew on the peony plants. It is a common disease we see this time of the year. There is no need to treat the plants for it right now. The best control for powdery mildew is to cut off the plant in the fall when it dies back and destroy the infested plant material so the disease cannot overwinter. It will not kill the plants.
5. This caller has tomato plants with leaves that are turning yellow and the plant is not producing tomatoes, any flowers produced fall off. What is wrong with his tomato plant?
A. This is likely due to environmental stress or possibly Septoria leaf spot. Make sure that the plants are watered 1 inch of water per week, they have mulch, and they are being watered from below. If desired, a fungicide can be applied. For more information view this NebGuide on Leaf and Fruit Diseases of Tomatoes. The poor pollination is common this year due to the heat. Give the plants some time and they should start to produce.
6. A caller has a sycamore tree that is shedding bark. What is wrong with the tree?
A. It is normal for sycamore trees to lose some bark. It is a tree that has a camouflage bark appearance due to the fact that it sheds some bark. Nothing to worry about or to do to fix it.
7. This caller is growing petunias in a hanging basket and the leaves are turning yellow. What is wrong with them?
A. This could be due to environmental stress. Make sure they are kept watered and placed in a location where they get full sun. It might also be from spidermites, look closely at the plant to see if there is any very fine webbing. If so, use a strong spray of water to knock the spidermites off and kill them.
8. A caller has bindweed in his garden and in his lawn. What can be done to control it?
A. In the garden, 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. In the fall, you can spray the lawn with a 2,4-D product.
9. How do you control purslane in the garden?
A. Purslane easily reproduces from cuttings so avoid hoeing or weed trimming through it while leaving pieces of the plant laying around on the ground throughout the garden. Purslane doesn’t like to be smothered, so a heavy mulch layer on the weed will help.
10. This caller has tiny, dark colored worms on her black-eyed Susan plant. She has used some Eight but she still has some. The leaves are also turning gray, how can she control the caterpillar?
A. This could be a checkerspot caterpillar. It is commonly found on sunflower, which is a closely related species of plant to this black-eyed Susan. This becomes a good pollinator butterfly. If she can relocate the caterpillars it would be best, or the Eight will just take some time to fully work on the caterpillars. The gray on the leaves is likely due to downy mildew or powdery mildew, not the caterpillars. Caterpillars will only chew holes out of the leaves, not leave any gray coloration to the leaves. Downy or powdery mildew are not very harmful to the plant and don’t need to be sprayed. In the fall, cut down the plant and discard the infected plant material so the disease is minimized for next year.
11. A caller has an ash tree that is about 15 years old and the outside leaves are now turning brown. What is wrong with it?
A. This could be due to leaf scorch due to the hot, dry conditions we have been facing lately. The tree should be fine, it will likely look rough the rest of the year. Make sure the tree has a mulch ring and that it is being watered for about an hour weekly with a sprinkler or slow trickle from the hose.
This caller also wondered about cougars in the area. He said he has seen a cougar with 4 cubs in the area. Will the cubs all stay here or will they move through to somewhere else?
A. Males can travel many miles and across the country. Females will stay around if there is food available and if a male doesn’t chase the female cubs away. The male cubs will likely move on when they get old enough to travel alone.
12. A caller has a tree that is pushing its roots up to be exposed out of the soil. What can be done about this?
A. Mulch will be the best option for these roots. The mulch will keep you from mowing over the roots which can damage the roots. Do NOT add soil on top of these exposed roots as that can limit oxygen for those roots and eventually kill the tree. You can make the area into a perennial garden under the tree, but do not raise the soil grade to do so and do not damage the roots to do so.
13. The final caller of the day wants to know why black crappie would be larger than white crappie?
A. This could be due to genes. The color gene may be linked to the size genes. So as the color is changed genetically, so is the size. It could also be that the predators in the area this caller was fishing in preferred eating the white crappie rather than the black crappie, causing only the smaller white crappie to be left with the larger black crappie. There are many factors that could lead to this difference in size between the 2 different colored crappie.
Summer is a great time of the year. Our flowers are blooming and our gardens are growing. However, sometimes we have disappointments in the garden such as when our vegetable crops don’t produce viable fruits for us to eat. There are many reasons for that, but most of them we cannot help with. Just be patient and they will work themselves out.
Zucchini, squash, and cucumbers have been known to produce fruits that develop into only a small fruit that then falls off the plant. The reason for this is due to poor pollination. The plants in the cucurbit family have separate male and female flowers. This time of the year, only the male plants are present in the plants. To have a fully pollinated fruit that will develop to maturity, the plant needs the female flower to provide the fruit itself, but it needs to be pollinated by the male flower. A female flower is easily identified because you will see a small forming fruit behind the flower. Often times, people see the flowers on the plant and then get discouraged because a fruit doesn’t form, but both types of flowers are necessary to get fruits.
Poor pollination can also be caused due to lack of pollinators. Bees and other insects are necessary in cucurbits to ensure that the pollen is moved from the male flowers to the female flowers. Some years the weather isn’t desirable to the pollinators or we have a low number of pollinators present, which will lead to poor pollination causing the small fruits to drop off before fully developing. This year it has been quite rainy which leads to less pollination because bees don’t like to fly in the rain. Be careful when spraying for squash bugs and squash vine borers to help reduce injury to pollinating insects.
Blossom end rot is another reason that small fruits may not fully develop and then fall of your plants. Blossom end rot is an environmental problem that affects many of the plants in our garden including tomatoes, peppers, cucumbers, squash, zucchini, and watermelons. This is actually a calcium deficiency within our plants. Calcium is often found in adequate quantities in Nebraska soils, however, it cannot be moved throughout the soil and into the plant without even moisture. So, the problem isn’t due to lack of calcium, it is due to uneven moisture in the soils. In Nebraska, especially in the beginning stages of plant development, moisture is typically uneven due to heavy rains in between dry spells. Using calcium on your plants will not help this issue. Give the plants time and they should begin to develop normal fruits with no blossom end rot on them later in the season. Typically, we only see blossom end rot for the first couple of harvests in a season. You can still eat the fruits that develop with blossom end rot, you would just need to cut the rotten portion of the fruit off.
Squash bugs and squash vine borer are coming to take over our gardens soon. This is the time of year to watch out for these problematic, common insects found affecting our cucumbers, zucchini, and the other cucurbits. Pay attention to your garden to help prevent damage. You can scout for the eggs of the squash bug. You will notice a group of tiny, copper colored eggs gathered near the intersection of the veins on the underside of the leaves. Remove and destroy the eggs as you find them to reduce the population. For squash vine borer, wrap the base of the plant in aluminum foil to stop the females from laying the eggs on your plant. You can use insecticides for both of these, just be careful to do it in the evening when the bees aren’t flying and don’t spray the flowers with insecticides to help with pollination.
This is the Q&A for the Yard and Garden show for May 19, 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: Jim Kalisch, Insect Diagnostician for Nebraska Extension
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 question of the day was from a gentleman wondering how to tell when to water his self-watering containers? There is no viewer or gauge to show the water level on the outside of the container.
A. Because a self-watering container is continually watering the plants in it, it can always be refilled. In this case, this container will keep your plants watered for at least a week to two so, they should be refilled before they completely dry up. I would suggest refilling the reservoir every week to 10 days.
2. A caller has bagworms in their cedars. What is the best way to see them before they get too big to treat?
A. They haven’t hatched yet this year. Mark the branch you have a living bag on with flag tape to check the same bag every week from now until they hatch. You can also place a few bags in a container and keep it in the tree to see when they hatch in the container. Wait a couple of weeks after the initial emergence to ensure that all of the bagworms have hatched before spraying. The bags in the shade will take longer before they hatch. Once they have hatched, Bt is a good insecticide to use when they are young or you can use a product containing bifenthrin in it for longer lasting control.
3. This caller is wondering what types of problems we can expect in the garden, lawn, and trees this year due to the excess rain?
A. The rains in the spring tend to lead to more fungal diseases this time of the year, but they are not terribly harmful and many should fade out as the summer heats and dries up. Many things to watch out for would include fungal diseases in the lawns and trees. We are already seeing Peach Leaf Curl, different fungi in blue spruces, anthracnose on the leaves, and mushrooms popping up in our lawns. We will also see more problems from earthworms and fungus gnats which are mostly nuisance problems.
4. How do you effectively control squash bugs in the vegetable garden?
A. Squash bugs are difficult to control in our cucurbit vegetables including zucchini, squash, pumpkins, gourds, melons, and cucumbers. The best option is to kill the adults when they first emerge to manage the population before it explodes. Watch for the eggs as they develop on the underside of the leaves to destroy them before they emerge. Switch to other chemicals for management besides just using “Sevin” for control, which they are becoming resistant to. There are also lures that can be used for them which might help early in the season.
5. A caller has an Oregon Trail Maple that leafed out early this spring. Now the leaves are slightly cupped and turning yellow along the edges. What would be causing this?
A. This sounds like frost damage. If the leaves came out early, they may have been nipped by a light frost in late April. We are seeing this problem throughout many trees and shrubs this spring. The leaves may drop entirely from the tree, but the tree will then push secondary buds to produce new leaves that are not injured.
6. This caller wants to know how to propagate a lilac and a hydrangea.
A. For lilacs: A cutting can be taken from the shrub. Cut off a small, pencil-sized, branch and place it into rooting hormone than plant it into a pot of gravel that is kept moist. Once roots have formed, the plant can be transplanted into the ground. They can also be propagated through a process called layering which is where you bend a flexible branch down to the ground and plant it to allow roots to form on the branch while it is still attached to the main plant. Once roots form, cut it from the parent plant and transplant it. There is more information on this in the NebGuide: Lilacs
Hydrangeas can also be layered to produce new plants or they can be divided. It is too late to do the division this year, but early next spring you can dig up the plant and use a spade to divide the main plant and replant the pieces. Depending on the side you can get 2-4 pieces from a divided plant.
7. Is cedar-apple rust damaging to cedar trees?
A. Cedar-apple rust shows up in the spring on cedar trees as a orange, slimy, ball with horns. This is the gall that opens up with rains in the spring. Cedar-apple rust is not harmful to the cedar tree, it just uses the cedar trees as an alternate host through the winter. When these galls are seen on the cedar, that is the time to spray any susceptible apple, crabapple, pear, or hawthorne tree to avoid damage to them. For more information view this NebGuide
8. This caller has a pink peony that hasn’t bloomed well this year. There is some discoloration and fuzzy appearance to the leaves and buds. What would cause that?
A. This sounds like botrytis blight, a common fungal disease to our peonies. It is not very harmful to the plant itself, so it is not necessary to control it. In the fall, make sure you remove and destroy all of the plant material to reduce the spread to your plants next spring.
9. A caller has a Chanticleer Pear with leaves that have black spots on them and the top isn’t leafing out this spring. What would cause that?
A. This could be due to frost damage as well. Or check the tree for oozing sap along the trunk or branches. The damage could be from borers. It might also be from fireblight which would cause the leaves to turn black on some branches where the end of the branch hooks over like a shepherds crook. Fireblight is likely since this showed up in the tree last summer. If it is fireblight, prune out the infected branches and dip your pruners into a bleach water solution in between the cuts.
10. This caller has roses that had dieback from the winter. She pruned them off in early April and now it looks like the only live growth is coming from the ground. What is wrong with her roses and will they come out of it?
A. Unfortunately, these roses seem to have more dieback from the late frost we saw in April. If there is no green growth showing up on the main part of the plant, it is likely that it has died back. The roots would be shooting the new growth from the ground, but that is not going to be the same type of rose that you had there before because our roses are often grafted. The growth from the ground would be from the rootstock so it wouldn’t be the size and color of rose that was originally purchased. Unfortunately there is nothing that can be done about that. It might be time to go and choose some new rose colors for your garden.
11. A caller has a river birch tree that dropped its leaves in the summer last year. The leaves now are yellow and only the top half of the tree has leafed out this spring. They are 20 year old river birch trees. What would be causing this problem?
A. Look on the branches of the tree for signs of bronze birch borer. Some of the signs of this borer would be rippling on the branches or holes in the stem or branches. If you find the signs of bronze birch borer, you can treat it now with a borer spray or with a systemic insecticide.
12. A caller has a river birch tree that was growing in a clump and one of the trunks of the group died out. Should it be removed now?
A. Yes, any dead part of a tree should be removed as soon as it is noticed. A large part of a river birch, like this, could be hazardous if left standing after it dies. Unfortunately, when that branch is pruned off decay will likely begin but there is no way to prevent that at this point. This will likely be a large portion of the tree removed and that large of a pruning cut may not ever heal over entirely. When a branch doesn’t seal up, decay can get into the tree causing more damage. We don’t advise painting the stump with anything.
13. A question came in via email regarding a red twig dogwood. This dogwood is 4-5 years old and has never been pruned. Following the storms this week, some branches are falling over blocking a mowing path. Can those be pruned now? What should be done with it in the future?
A. Broken branches can be removed at any time. If these are just bending over, they could still be removed if necessary, but they may pop back up to their normal standing position. For future, red twig dogwoods should be pruned to the ground every 3-5 years to maintain that good red color on the twigs. They should be pruned in the late winter to early spring.
14. A lady called who has a Cranberry Bush Viburnum that has dead branches in it. Can those dead branches be pruned out now?
A. Yes, dead branches should always be removed when they are noticed. Check to ensure that these branches didn’t die due to Viburnum borers, if so, treat with a borer spray or systemic insecticide.
15. The last caller of the day has 2 different plants that have problems. A maple tree has brown specks on the leaves and they are falling off the tree. A Peony bush has leaves that are turning yellow along the edges of the leaf. What would be causing these two problems?
A. These both sound like frost damage. They will both be fine. The maple may drop all the damaged leaves and put on new growth.
This is the Q&A for the Yard and Garden show for July 8, 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: Dr. Paul Read, Viticulture Specialist for Nebraska Extension with Guest Intern Vivian from China
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 if they can prune the Cleveland Pear tree that has branches that are low and too tight to the trunk?
A. The best time for pruning a tree like this would be while it is dormant. For a situation like this where the caller is only removing a few branches to help with the growth of the branches and to reduce future problems with the tight branch arrangement it would be fine to remove them now. It would be better to remove branches like this before they break in a storm due to weak attachment to the trunk.
2. A caller has Anjou pear trees that were planted in 2013. Now the bark from the graft union up about 10-12 inches has the bark peeling and now has some black leaves. What would cause this?
A. This would be from sunscald. There is no way to fix sunscald once it occurs. Don’t paint the wound with anything, allow it to heal itself. The black leaves could be due to fireblight. You can cut 6-8 inches past the diseased portion of the limb to cut the fireblight off the tree. The black could also be anthracnose which is not damaging to the plant and there is no need to spray anything for anthracnose.
3. This caller has an oak tree that is dripping sap on the vehicles parked under it. What would cause this?
A. Aphids feeding on the leaves of trees will excrete honeydew that can drip on vehicles underneath the tree. Aphids are not very damaging and have a lot of predatory insects that feed on them. They can be sprayed with sevin or eight or another general insecticide, but they should fade out on their own with predator insects.
4. A caller has blue spruce trees that look dirty but the tips are still green. What would cause this?
A. This is most likely due to environmental stress from the heat and humidity. If the ends of the branches are still green, the tree will be fine. Make sure your tree has a mulch ring around it and that you keep it well watered in the heat of the summer.
5. This caller has a patch of lilies where a quarter of the patch has only grown to be about 6 inches tall for the past 2 years. The rest of the patch looks good, but this area doesn’t look healthy. Can these be improved?
A. This could be due to hardiness in some varieties that are only suitable for our environment for a couple of years. It also could be due to some bulb mites. It would be a good idea to dig up some of the bulbs to see if they have any damage on the bulbs.
6. A caller has a pine tree with a lot of sap on the branches and the grass in the lawn won’t green up. Why is this?
A. Woodpeckers or insects feeding on a pine tree can cause sap to leak from the wounds left behind. The insects can be controlled with bifenthrin or permethrin (eight). If it is woodpeckers, the damage is minimal and will not cause any problems to the tree. Check how much water the lawn is actually receiving by using catch cans during the water intervals normally followed. Lawns need 1 1/2 inches of water per week. If the water is fine, there are a lot of fungal diseases in the lawn, it could be one of those. Fungal diseases in the home lawn are usually sporadic and therefore don’t require fungicide applications.
7. This caller lives on an acreage surrounded by farmground. She is considering growing grapes on this large plot of land. Are grapes easy to grow and would grapes have a benefit to the wildlife in the area?
A. Grapes are a large commitment, especially if you plan to sell products from them. You can be successful with only a few plants for the family to use for grape production. A few good choices for this area would include Frotenac or Valiant. The first year the grapes would need extra care, but after that they would be more self-sustaining. Deer will feed on the foliage. If you decide to grow your grapes for commercial use, register your acreage with the driftwatch website at www.fieldwatch.com to help avoid problems from drift since grapes are very sensitive to drift damage.
8. A caller has strawberries that were planted and now have very small fruits and the plants are not making runners.
A. Everbearing strawberries are typically very small for fruit size. You might try planting some newer varieties that are June bearing to get larger fruits. Some good choices would include honeoye or albion or sparkle.
9. This caller has an ash tree that is 7 years old and the tree snapped off in the wind. There is mold in the trunk and it is suckering. What can be done to plant a new tree?
A. You can get a company to come in and grind out the stump or rent a stump grinder to do it yourself. The suckers that keep growing back will continue to for a few years, they can be cut out and treated with a roundup or 2,4-D product. You can plant a new tree within just a few feet of the old tree, since this wasn’t a very large tree yet.
10. A facebook photo came in with a odd structure that appeared by a tree. What is this?
A. This would be a stinkhorn fungus. They are not harmful to the plants growing in the area. There is not control other than mechanical removal of the fungus. Do not eat these as they are not edible, they would be a poisonous mushroom.
11. The last caller of the day has tomatoes in a raised bed. When they ripen for harvest, the end of the tomato seems blighted. What would cause this?
A. This is blossom end rot. It is a calcium deficiency that develops in our plants in drought situations because calcium is only available to plants after it has been dissolved in water. There is no control for this, it should only last for a few weeks early in the growing season and then the plants should grow out of it.