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.

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Yard and Garden: June 16, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for June 16, 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 from UNL 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 caller of the day has a Daylily that has yellow streaks on the leaves. What is causing this? She also has Roses that are getting yellow leaves and sprayed a rose product containing both an insecticide and a fungicide. Will this work for the roses?

A. The daylilies likely have Daylily Leaf Streak, a fungal disease common on daylilies. It would be best to remove the infected leaves and destroy them from the plants as you see them and clean up the plants in the fall by cutting off all the foliage and destroying it for winter. It will also help to water from below the plants rather than using an overhead sprinkler. Also, it sounds like her daylily plants are overgrown, this fall it would help to dig and divide them to increase air space. As for the roses, they could be dealing with black spot or rose slugs. The fungicide and insecticide combined product will work to reduce the incidence of both of these problems.

2. A caller wants to know when the best time to transplant asparagus and what can be done for a cypress tree turning yellow?

A. Asparagus is best planted and transplanted in the spring. However, if this is an old patch of asparagus, it would be better to just start from new crowns. Either way, you need to wait 3 years to harvest to allow the roots to develop. Trees that turn yellow instead of their deep green color through the growing season are often lacking iron. The best management for Iron chlorosis is to use a trunk injection of iron. However, with cypress trees, it is often difficult to get them out of this condition and multiple years of trunk injections can start to stress the tree out to the point of death in some cases.

3. This caller has peonies and moonflowers in her yard and wants to know when the best time is to transplant them and how to prepare the area that was rocked to get these plants to grow well?

A. Spring will be best for establishment, but fall would be a second best option to transplant these plants. Remove the rocks that were in the new location and then till the soil, adding compost in as you till to improve the structure of the soil and add some nutrients back into the soil. When moving peonies, make sure that it is planted at the same depth in the soil, to deep and the plants will not flower. After you have planted, add some wood chip mulch around the plants to help them stay cool and hydrated. Water as needed.

4. A caller has a large blue spruce that has some browning on the needles and those needles are beginning to fall off the tree. This has started at the bottom of the tree and is moving upward through the tree. What is causing this? Can her tree be saved?

A. This could be one of two things, either a fungal disease or spidermites. After discussion, the caller stated that the needles are more of a reddish brown, which is distinct for a fungal disease called Rhizosphaera, which is common now. The trees can be sprayed with a fungicide to reduce the spread of the disease. Over time, the trees will grow new needles.

5. This caller recently planted 2 new 7-feet tall blue spruce trees. They are watering these trees at least once a week for 30 minutes and they are mulched in with straw. Now, the lower branches are droopy and wilted. Do these branches need to be removed?

A. These trees are dealing with transplant shock and need some time to build some new roots and get over the shock. Leave the branches for now and continue to water as needed.

6. A caller has a volunteer tomato plant that is about a foot tall. Can it still be transplanted now to be grown in the garden?

A. Yes, it will still be fine. The volunteer tomato will not come true from seed, so it may not be the same type of tomato as what was planted last year, but it should grow fine.

7. A caller has a bald cypress that has needles that are curling. What would cause this?

A. This sounds like drift from 2,4-D or another type of herbicide. This would happen if people are spraying these herbicides now that the temperatures have risen so high. Slight damage may be only aesthetic this year. Multiple years of damage can start to cause stress and even death to the tree.

8. This caller is growing grapes in his backyard. These grapes have black spots on the vine that the caller sees most years. The grapes then shrivel up before they can be harvested. What would cause this?

A. This sounds like a fungus. It would be best to get on a fungicide schedule with your grape plants to keep this fungus from returning every year. For more information on when and what to spray, view the Midwest Small Fruit and Grape Spray Guide

9. How do you stop zoysia grass from spreading in Tall Fescue and Kentucky Bluegrass?

A. Fall fertilization will push zoysia to grow when it is going dormant because it is a warm season grass. This fertilization will be beneficial to the cool season grasses.

10. A caller has Canna bulbs. Is it too late to plant them yet this year?

A. They can plant them to keep them alive and get sugars built up for next year, but they will likely not bloom this year. Cannas have to be dug up and stored indoors over the winter and if they are left out of the ground for 2 seasons, they may not have enough energy to grow after that. Planting the bulbs this year to get sugars for growth next year would be the best place for them to be stored.

11. This caller has patches of round grass in the lawn. How can it be controlled?

A. This is likely a perennial grassy weed such as windmill grass, orchardgrass, or quackgrass. These can be controlled with roundup and then overseeding or with a mesotrione product such as Tenacity. For more information on these weeds, view this article from Lancaster County Extension.

12. A caller has a spirea bush with dead wood in it. Can it be cut back now?

A. Yes, this isn’t the best time for a summer blooming spirea, but it will be fine. Summer blooming spirea’s should be pruned in the late winter, such as February and March for best blooms. This can be pruned back to 6-8 inches from the ground. However, if it is a 50 year old plant, as the lady stated, it may be getting old and may not return from a rejuvenation cutting as it may be dying due to old age.

13. How do you get rid of poison ivy which is growing in rose bushes?

A. It will be difficult to remove the poison ivy and not harm the roses or not get a medical reaction from the poison ivy while working to remove the posion ivy. Paint roundup on the leaves of the poison ivy now, being careful not to get the glyphosate on the roses. It may take multiple applications to kill the poison ivy entirely. Wear long pants, long-sleeved shirt, gloves, socks, and shoes when applying this to avoid getting a rash from the poison ivy.

Poison Ivy-David J Moorehead, Univ of GA, Bugwood

Photo of Poison Ivy courtesy of David J. Moorhead, University of Georgia, Bugwood.org

14. This caller has a trumpet vine that is creeping into the lawn. How can it be controlled in the lawn without damaging the parent plant?

A. Just keep mowing it off. These are likely runners from the main plant and if a pesticide is used to control the runners, it will go through the plant into the roots of the main plant.

15. This caller is curious if poison ivy oils can transfer to pine cones on the ground surrounding the poison ivy plants? She is also curious if she can trim her Iris plants back now or if she has to wait until the fall?

A. According to Clemson University, the poisonous oils can remain active for months on objects. It can be picked up on tools, clothing and the fur of pets. Anything that may carry the oil should be carefully washed. Even dead plants or roots may cause allergic reactions for a couple of years. So it is best to clean the pine cones that came in contact with the poison ivy. For more information, see this guide from Clemson

As for the Iris plants, you need to wait until fall to cut the leaves back when the leaves turn brown for the year. It gives the plant time through the summer to build up sugars to help bloom early next spring.

16. What type of tree would be recommended that is smaller but provides good shade?

 

A. Dwarf Chinkapin, Pawpaw, Redbud, Crabapple, Serviceberry

Yard and Garden: June 24, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for June 24, 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: Jim Kalisch, Insect Diagnostician for UNL Extension

1. The first caller of the day has summer squash that grows about 3 inches long then they get soft and fall off of the plant. What would cause this?

A. This is probably blossom end rot. This is an environmental condition where the blossom end of the fruit of the plant rots, just as the name implies. This condition occurs often in the beginning of the season and will fade out later in the growing season. Blossom end rot is caused by a calcium deficiency in the fruit. In Nebraska, there is rarely a lack of calcium in the soil. Blossom end rot occurs when plants cannot pull calcium up quickly enough for developing tissues. Calcium must be dissolved in water to move within a plant, so dry soils can increase the problem.

2. A caller has tomatoes that the leaves are starting to curl up. They have buckets around the plants and each night they fill the bucket up with water. They also have white spots on the pumpkins. What is wrong with these plants and how can they be salvaged?

A. The water regime being followed is not the best practice. The buckets are holding a lot of heat in around the plants and filling each of these buckets every night is giving the plants a great deal of water. It would be best, this late in the season, to remove the buckets to reduce heat stress and use a sprinkler for a couple of hours or soaker hose for a few hours every other night to give the plants the right amount of water. The white spots on the pumpkins could be either powdery mildew or sunscald. Leave them alone, it should fade out and it will not cause a great deal of damage to the plants.

blossom end rot zucchini

The Zucchini on the left in this photo has blossom end rot

3. This caller has cucumbers and squash that the blossom end of them are rotting and then they fall off the vine. What would cause this?

A. This is blossom end rot. This is an environmental condition where the blossom end of the fruit of the plant rots, just as the name implies. This condition occurs often in the beginning of the season and will fade out later in the growing season. Blossom end rot is caused by a calcium deficiency in the fruit. In Nebraska, there is rarely a lack of calcium in the soil. Blossom end rot occurs when plants cannot pull calcium up quickly enough for developing tissues. Calcium must be dissolved in water to move within a plant, so dry soils can increase the problem.

4. A caller has peppers that had one bloom and now they are not setting any peppers on the plant. He fertilized it earlier this spring. What would cause this?

A. This would be due to low pollination. In this heat the insects are not moving around as much to pollinate. Give it time and the plants should begin blooming in a week or so.

5. This caller has a pin oak that the leaves are curled on the edges. What is wrong with this tree?

A. This could be from a gall gnat. This will cause the leaf margin to roll tightly. It could also be from herbicide drift. There is no control for either problem and the tree should outgrow both of these problems.

 

Stable Flies on Dog JAK140[1]

Stable Flies from the back of a Dog, Photo by Jim Kalisch, UNL Entomology

6. An email came in with the following question: The other day I found a fly on my dog’s head. When I went to grab it off, there was blood on her. Upon closer inspection, it looked more like a cross between a fly ad a bee. It’s triangle-shaped. What is it, how can I protect my dog?

A. This could be either a robber fly or a horse or deer fly or a stable fly. All of them can be kept at bay with fly repellent sprays or collars. These contain pyrethrins, essential oils and other ingredients not harmful to dogs. DEET is not advised for pets. It would be best if the dog owner to got information from a vet. Other tactics would be to reduce or eliminate fly breeding substrates, such as lawn clippings, pools of water, etc.

7. A caller planted string beans this year from both new and old seed. For some reason, the new seed seems to have more vigor even though they are planted right next to each other in the garden. Is it true that the new seed is more vigorous than the old seed?

A. Not necessarily. If the 2 plants were different varieties that would make a difference. Seed stored correctly should grow just fine for a few years after original sale. However, if the seed is stored in a location of high humidity or high temperatures, that can reduce the vigor in the seed.

8. This caller has a hanging basket of petunias. The buds on the plant are brown and full of black “balls”. She cut the plant back and put Sevin insecticide on it. What would cause this? Does she need to cut the buds off of the plant?

A. This is probably tobacco budworm. The black “balls” are probably fecal pellets from the caterpillar. Sevin may not be effective on this pest, so try Bt to kill only caterpillars and not harm any pollinators. Cut off the bloom to encourage new blooms to grow.

9. A caller has tomato plants that have grown to 4-6 feet tall. Now the leaves are curling and some are turning brown/black. What would cause this?

A. This caller has been using a hand wand to water at the base plant individually for a few minutes. This is not enough water for such large plants. It would be better to do a deep watering with the use of a soaker hose for about 4 hours 2-3 times per week or with a sprinkler for 1-2 hours 2-3 times per week if natural rains do not occur. Vegetables need about 1 inch of water per week for optimum growth. A little over that is fine, but we don’t want more than 2 inches, unless it comes as rain that we can’t control.

10. The final caller of the day has potatoes that were bored through the stem. What could that be and how can it be controlled? This caller also has green beans with yellow spots on the leaves and the beans are very curled rather than straight. What would cause this?

A. The potatoes have stalk borer. This insect pest should be about through with their damaging stage so there is no need to control it. As for the green beans, the leaves have a leaf spot fungus, there is no need to control it in a home garden, it should fade soon as the weather has warmed up and dried up. Remove these infected beans, that could be due to the hot weather that has caused a malformation in the growth of the beans, it should fade as the season continues on.