Yard & Garden: June 26, 2020

This is the Q&A for the Yard and Garden show for June 26, 2020. 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 31, 2020. 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: Kyle Broderick, Plant Pathology Extension Educator

1. The first question of the show was from a caller who missed the answer last week on the show regarding controlling grass in her red raspberries.

A. Mulch will be the best option for this area. Red raspberries grow upright so they don’t shade out the weeds as much as black raspberries. Glyphosate or Roundup can be used carefully around the plants as well. Use some type of a barrier between the grass and raspberries if sprayed or use a sponging type of applicator or paint it on the grass.

2. A caller has a mandevilla with leaves that are turning yellow with black edges. She also has a gardenia that is getting yellow leaves with black edges. What is this and can she fix it?

A. These plants are growing in containers being watered often enough. Be sure to check the drainage when watering to ensure the drainage holes are not clogged. Water containers until water runs out of the drainage holes. If that isn’t happening there may be a clog which could lead to root rot because the plants would be sitting in water. Be sure to test the soil before watering to ensure it is dry. Stick your finger into the soil to see if the soil is dry, if it is still wet, do not water until it has dried.

3. This caller has a new lawn, she thinks it is fescue. It was planted last year and last fall it looked great. However, when the hot, dry weather began this year, a few patches in the lawn dried up and look dead now. The lawn was described as drying up almost overnight as soon as the heat started and there was a black coloration to the plants. What is wrong with the lawn?

A. This could be drought injury, grubs, or pythium blight. The new plants likely don’t have a full root system yet which would cause it to dry up faster in the heat. Watering 1-1.5 inches per week would help with drought or heat stress. If she pulls up the turf and there are no roots, it would be from grub damage. Grubs can be treated now with a lawn grub control such as Merit or Grubex. If she takes a handful of the blades and puts them into a baggie and leaves them overnight, she might notice a fishy odor that would indicate pythium blight. Pythium will go away on its own, it doesn’t harm the crown of the plant and it will regrow.

4. A caller planted new grass a year ago after a new home was built. It was growing good, but now there are some grass plants that turn brown and have stickers on them. Would that weed have been in the turf seed? How can it be managed?

A. These are likely sandburs growing. They were not in the grass seed, they were most likely from the soil. When a new home is built, the area that was undisturbed before has now been worked up. Sandburs live in rocky, bare soil areas where grass doesn’t grow. They would have already been there when the home was built. Sandburs are an annual grassy weed, similar to crabgrass. They can be controlled with crabgrass controls. In the spring use a crabgrass preemergence herbicide and now that the sandburs have already germinated for the year, Drive or another product containing quinclorac can be used.

5. This caller has a tree row at his house. There are old firs or pines that seem to be dying out and now he has planted a row of blue spruce. The blue spruces are turning brown, starting on the inside of the plant moving outward. The damage on these spruces is on the side facing the old trees. What is wrong with these trees and what can be done to help them?

A. The old trees could be nearing the end of their life and may just be dying of old age. This does happen. As for the blue spruces, it could be a needle cast disease which is common on spruce trees and is prevalent now. It is not effective to spray with fungicides now, but next spring they can be treated with chlorothalonil. They should be sprayed when the new needles are half expanded and then again 4 weeks later when the needles are fully expanded. There could also be some problems on the spruce trees from the location near the dying firs or pines. They are likely not getting the airflow they need and the needles are staying wet longer. This could be intensifying the needle cast disease.

6. A caller wants to know what our opinion is on transplanting trees now? He would be moving them with a tree spade.

A. Regardless of the size of the tree or how it is moved, it would be difficult to keep a tree alive in this heat. If planting from a container grown tree, there would not be much for a root system on the new tree so it would have difficulty getting water as often as needed. If it is brought in with a tree spade, many of the large roots will be cut and it would still be hard for the tree to get the moisture it needs. It is best to plant trees in the spring or fall, when it is cooler and rains more often to keep the tree well watered through the establishment period. They are best planted prior to Memorial Day and then again after Labor Day. We advise against planting in the summer months.

*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.

Yard & Garden: April 10, 2020

This is the Q&A for the Yard and Garden show for April 10, 2020. 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 31, 2020. 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: No guest host due to COVID-19 and social distancing

1. The first caller asked when the best time is to transplant peonies?

A. The best time is in the fall. They can be done in the spring though, as well. You may want to mark the depth that they are planted at currently to ensure they get planted at the same depth at the new location. Use some masking tape or some other way to mark their depth now. If peonies are planted too deep, they will not flower.

2. A caller has Austrian pines that started turning brown last year. He was told to spray them with a copper fungicide in the spring, is that correct?

A. This sounds like dothistroma needle blight which is common on Austrian Pines and Ponderosa Pines. This disease will cause the tree to turn brown, typically from the bottom up with brown bands on the needles upon closer inspection. Needle blight is best controlled with 2 applications of copper fungicide, one in mid-May when the new needles have emerged to about half their size and a second application in mid to late June.

He also asked if he can plant asparagus now?

A. Yes, asparagus is a spring plant. It can be planted in April or May. Asparagus should be planted in a trench 6-8 inches deep. The recommendation has always been to cover the crowns with 2 inches of soil at first and wait until they emerge to continue to add 2 inches of soil each time until the soil level is even with the surrounding soil. However, research shows that this isn’t necessary. The asparagus should still be planted in a trench 6-8 inches deep, but it can be completely covered back up right away to still be successful.

3. Is there any herbicide that can be used to control weeds in a pumpkin patch?

A. Unfortunately, the majority of these herbicides for use in pumpkins are restricted use and can only be purchased and used by individuals with a pesticide applicator license. For a general backyard pumpkin patch, mulch will be your best option to manage the weeds before they become established. Hand pulling through the season will help as well.

4. This caller had planted spinach and radish a few weeks ago. They had emerged and then were covered with snow and ice last week. Now the tops have burned off entirely. Will they regrow?

A. Unfortunately, if the entire tops of these plants were killed with no green showing, they will not likely regrow. You can wait a week or so to see if they regrow, but it may be time to replant these crops. If they were small they don’t have very much for reserves left in the roots to get new growth back.

He also has asparagus growing but it is continually very spindly. What can be done about that?

A. When asparagus is small and spindly, it may need some fertilizer to help it grow thicker, larger stalks. A general garden fertilizer can be used now, in the spring or a manure or other type of fertilizer can be used in the fall.

5. A caller has a 7 year old peach tree and very old apricot trees that are in full bloom right now. With the freezing temperatures predicted for the next several days, will they produce fruit this year?

A. It is not likely that they will survive these freezing temperatures at the stage they are at. Temperatures are predicted to be in the low 20’s for several nights starting on Sunday. According to research by MSU, apricots in full bloom will have 10% blossom kill at 27 degrees and 90% blossom kill at 22 degrees. Peaches in full bloom will have 10% blossom kill at 27 degrees and 90% blossom kill at 24 degrees. If we can stay a little warmer, at that 27 degree mark you should still see a good fruit set this year, but if we do get the cold temperatures predicted it is not likely to have much of a crop. To see more scenarios and more fruits, visit the Spring Freeze Damage Thresholds Guide.

6. This caller had broccoli growing in her garden. The foliage was burned by frost, but she had planted the plants in a tin can with the bottom cut out placed in the soil and placed a bucket over the plants during the cold nights. Will the plants survive?

A. There is still green in the stems, so they should come back. Give the plants a week or so to determine if new leaves emerge. If they don’t put on new leaves in the next week, it is likely that they won’t survive and need to be replanted. Broccoli can take temperatures down to 26-31 degrees, so they should have been ok. You will want to make sure that the plants are covered again, overnight, for the next few days while more cold temperatures are predicted. The predicted temperatures are lower than what the broccoli can survive under normal growing conditions.

7. Is it too late to plant peas? Can tomatoes be planted now?

A. The peas are ok to be planted now, but it might be a good idea to wait until after this next week when the temperatures are to get very cold overnight. Peas can only take temperatures down to 31 degrees. Tomatoes are a warm season crop and shouldn’t be planted until the beginning of May. If planted in a wall-of-water or other protective method, they can be planted in late April. I wouldn’t push the plants too much earlier than that because they don’t survive cold temperatures and won’t grow.

8. A caller has a blue spruce tree that is losing the needles on the east, southeast side of the tree. This area that is dying is not on the shady side of the tree. The trees are about 20 years old.

A. This caller sent photos to me after the show. After further discussion, it was determined that the tree could possibly have a few issues that are common on blue spruces. I assume they may have had some spidermites last summer that killed off a lot of the needles as well as needle cast disease. The spidermites can be sprayed off with a strong spray of water that will knock them off and kill them. There are miticides labeled for use on spidermites, but sometimes using pesticides can kill the predatory insects as well for spidermites causing more of an outbreak. The needle cast disease can be treated by spraying chlorothalonil or copper fungicide on the trees. Fungicide applications should be made in May when the new needles are 1/2 to 2 inches in length and every 3-4 weeks as rains continue. For more information on needle cast, view this publication from the Nebraska Forest Service.

9. Should marigolds be planted into containers or directly into the ground for best growth?

A. Either will work just fine. Marigolds will make a good container garden plant or they can be used among your perennials and other annuals in gardens in the ground.

10. This caller wants to know how to keep grass out of the asparagus? When should preen be used if that is an option?

A. Preen will work well on asparagus. Make sure you use the preen that is labeled for use in asparagus. It can be applied anytime in the early spring on established plants. When dealing with newly planted asparagus it would be best to wait until the asparagus has begun emerging from the ground. Mulch will also help with weed management in asparagus. Grass clippings, straw, or wood chip mulch can be used on asparagus. If applied early enough, the mulch can be a very effective weed control.

11. Can preen be used on flower beds?

A. Preen would be fine in flower beds, as long as the flowers in the garden are listed on the label of that Preen product. However, if any of the flowers are annuals coming up from seed or perennials that are allowed to grow through seed dispersal in that garden, the preen will stop the germination of those coming up from seed. Do not use it in areas where you plan to grow via seed.

12. A listener wondered about relocating lilacs. Can it be done, if so when?

A. Yes, they can be transplanted. The fall would be the best time for this.

13. The last caller of the day has some hickory and pecan trees to plant. Can they be planted around a black walnut tree?

A. Yes, hickory and pecan trees are in the same family as black walnut and therefore are not negatively affected by the juglone that the black walnut produces to reduce weeds around it.

He also wondered if a pawpaw tree can be planted around other trees?

A. Yes, pawpaw is best grown as an understory tree with partial shade.

Yard and Garden: March 30, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for March 30, 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: Justin Evertson, Green Infrastructure Coordinator, Nebraska Forest Service

1.The first caller of the year has brown rot in her apricot and cherry trees. How can this be managed this spring?

A. Brown rot is a fungus that affects the fruit of stone fruit trees. Spraying with Captan or Chlorothalonil products or using an Orchard Fruit Tree Spray throughout the growing season will reduce the disease. Avoid spraying during bloom if using a combination spray that contains an insecticide to avoid damage to pollinating insects. For more information on spraying and timing, visit food.unl.edu/local-food-production and click on ‘Managing Pests in Home Fruit Plantings

2. A caller has been advised to use a type of fescue called ‘Water Saver Fescue’ because it is more drought tolerant. Would this be a good turf choice?

A. This variety is a turf-type tall fescue variety that is an RTF variety. The RTF is a new type of tall fescue that forms rhizomes, allowing it to fill in a yard rather than just form clumps like the traditional tall fescue. Turf-type tall fescues are preferred to other types of grasses because they do well in our environment and are more drought tolerant than other turf species, such as Kentucky Bluegrass. This wouldn’t be any more drought tolerant than any other turf-type tall fescue species, but it would be drought tolerant.

3. When should a person fertilize their lawn?

A. If using the maximum fertilizer applications for a year, we recommend fertilizing with the holidays: Arbor Day, Memorial Day, Labor Day, and Halloween. It is not necessary to do all of these fertilizer applications. If you leave the grass clippings on your lawn, that replaces one fertilizer application over the course of a growing season. If you only apply fertilizer one time per  year, the best time is at Halloween. If you would like to apply 2 applications per year, the other time would be to add an application on Arbor Day.

4. This caller wants to know what is best to use in a vegetable garden to keep the weeds down?

A. In a home vegetable garden, mulch is going to be best for weed control. There are a lot of mulch products that can be used in the garden to reduce weeds including: wood chips, grass clippings (that have not been treated with any pesticides), newspaper, leaves, and cardboard.

green-asparagus-pixabay5. A caller wants to plant a new asparagus bed. How should she go about planting and caring for her asparagus?

A. Asparagus is a great plant for a home garden. Many people want to get plant starts from a neighbor to start their patch, but it is best to just purchase a new set of crowns. When planting asparagus crowns, dig a trench 8-12 inches deep and bury the crowns only under 2 inches of soil. As the plants poke up through the soil, add more soil until the soil is level. Avoid harvesting asparagus until the third season of growth to allow the crowns enough time for root production. For weed control, mulch is best, the same mulches used on a vegetable garden work great for asparagus beds. Preen that is labeled for use around asparagus can be used in the spring to prevent annual weeds from germinating. In late May to early June, when finished harvesting asparagus for the year, you can break all the spears off below ground, leaving no green growth above ground, and spray glyphosate over the bed to reduce weeds.

6. This caller has Colorado Spruce trees with needles at the bottom of the tree that are turning brown. What is wrong with the tree and how can it be fixed?

A. This is likely due to needle cast disease. You can spray the tree for needle cast in May using a liquid copper fungicide. For more information, view this Nebraska Forest Service publication on Diseases of Evergreen Trees.

7. When is a good time to transplant Iris and Peonies?

A. The best time is in the fall, but it can be done now. They may not bloom this spring if you move them now, but will bloom again next year. Be sure to get the peony planted at the same depth it is now or it won’t bloom.

8. A caller has a vine growing on the trees they thought was poison oak. How can it be controlled?

A. It is likely that this is woodbine or Virginia creeper. It doesn’t all have to be killed off, it makes a great groundcover. Cut off the parts growing up the tree and leave the rest for a groundcover. If you need to manage it cut it off and treat with glyphosate or triclopyr or just hand pull.

9. The final caller of the day has recently read that trees can “communicate” to other trees if they are attacked by a pest to help the other tree prepare to defend themselves from the pest problem. Is there any research on this?

A. There is a theory that trees communicate. A German Forester is looking into this idea further. Here is the Article from the Smithsonian Magazine regarding this topic and the research on how trees communicate.

Yard and Garden: July 17, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for July 17, 2015. 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 31, 2015. 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: Steve Karloff, with Special Guest Jennifer Morris from the Nebraska Forest Service

1. A caller has a 35 year-old spruce tree that has needles that are turning pink, brown starting at the bottom of the tree on the east side. What could be causing this?

A: This sounds like needle cast disease, a fungal disease, that is common in blue spruces this year due to the rains in the spring. The treatment period for this was in the spring prior to development of the disease. It should not kill the tree. Make sure that the tree is properly cared for with 1 inch of watering per week, applied slowly, and a mulch ring of 2-3 inches deep.

2. A gentleman has cucumbers that are developing improperly. They are large at one end and very skinny at the blossom end of the fruit. What would be the issue with this odd developed fruit?

A: This could be due to environmental conditions. Dry conditions, which we have seen since the rain quit in early June, could lead to poor fruit development. It can also be due to poor pollination. Avoid use of insecticides if pollinator insects such as bees are present around the fruit.

Green June Beetles
Green June Beetles

3. A gentleman brought in some metallic green beetles that are very large. What are they?

A. These are green June beetles. They are not damaging to our plants and therefore require no management tactics.

4. A caller has a shady area on the North side of the house. What would be a good groundcover for this area?

A: Holly, purple leaf wintercreeper, vinca, lily of the valley, hostas, snowberry, coralberry, Bleeading hearts, or coral bells will all grow well in a shady environment on the North side of a house. Many of these will stay around 2 feet or shorter, but the snowberry and coralberry and holly will all get taller. A good mixture of shade plants will look nice around a home.

5. A caller has an oak tree that is well established. He is looking for a good groundcover to plant underneath that.

A: hostas, bleeding hearts, coral bells, vinca, and purple leaf wintercreeper will grow well under the shade of a large tree. Grape hyacinth can also be planted around the other plants for early spring color and fragrance with little impact to the landscape later in the season.

6. What are the tall blue flowers growing along the highway currently?

A: Chicory. This is a wildflower often used in roadside mixes or in native prairies. They have a sky blue flower and most of the leaves are located at the base of the plant rather than up along the taller flower stalks.

7. A gentleman has a windbreak of cedars that is dying. He sprayed 2,4-D underneath to kill the wild cucumber. The trees are 30-40 years old and they have bagworms but he has not treated. What can he do to keep the windbreak?

A: This could be due to bagworms. They are heavy this year and right now is a good time to spray with many general insecticides including sevin, eight, malathion, Bt, or Tempo. This could also be a side-effect of the 2,4-D that may have moved into the root zone more quickly with the rain events this year.

8. A caller wanted to know what the best recommendation for mosquito control prior to a get-together would be?

A: Mosquitoes can be controlled for a few days by using a hose-end sprayer with permethrin or bifenthrin which have a longer residual than some other insecticides. These sprays need to focus on the shrubs and trees and tall grasses around the yard where the gathering will occur and they should only be done 2-3 days prior to the gathering. Aerosol foggers that contain pyrethrins can be used shortly before the party begins to help reduce mosquito populations as well. For the time of the gathering, tiki torches and insect repellents containing DEET will help reduce additional mosquitoes.

Cedar-Hawthorn Rust
Cedar-Hawthorn Rust

9. A gentleman brought in a pear leaf with orange spots on the leaves. What would be causing this?

A: This is due to a rust disease, Cedar-Hawthorn Rust. It is very common this year due to the wet spring. The timing for management is in the spring, May and June. There is no need to control it at this point in the season. See this NebGuide on Cedar-apple rust and related rusts of apples and ornamentals.

10. A caller has a maple that is 10-12 years old with leaves that are wilting, turning brown, and falling off the tree. What could be the cause of this?

A: Look for green tissue under the bark on the branches. This could be due to a high flush of growth in the spring that put on too many leaves for the tree to maintain now that the weather has dried up and gotten hot.

11. The same caller wondered if there was a control method for pine wilt?

A: No, the best control would be to remove and destroy the tree as soon as possible after the disease is noticed in the landscape to reduce the spread of the disease to other trees.