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.

Yard and Garden: June 22, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for June 22, 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: Kathleen Cue, Dodge County Extension Educator

1. The first caller of the day has cauliflower that is turning purple in the garden. What is causing this and can it still be eaten?

A. This is a response to the heat. For next year, blanche the heads just after they begin to form by tying the large leaves up around the cauliflower heads to protect them from the sun or purchase self-blanching varieties. This cauliflower can still be eaten even though it has turned purple.

2. When is the best time to move asparagus?

A. Spring would be the best time for planting asparagus. It is more beneficial to just start a new asparagus patch rather than transplanting. It would be difficult to get all of the plant and there are a lot of newer varieties that will do better with heat and other conditions. If you transplant what you already have growing, it is still best to wait 3 years before heavy harvest again, so it would be beneficial to start over since this asparagus bed is already 20 years old.

3. A caller has nutsedge in their lawn, how can it be controlled? Roundup didn’t seem to work for it.

A. Roundup would not be effective in this situation because roundup is for grass control, while nutsedge is a sedge. For best control of nutsedge, it is best to use either Sedgehammer or Tenacity. Both of these chemicals should be effective, but they should be applied prior to the first day of summer to reduce the population for next year. Also, nutsedge tends to grow in areas of the lawn where the soil is compacted or water tends to sit, reduce the compaction and get the turf growing better to control the sedge better.

Yellow Nutsedge-Howard F. Schwartz, Co. State Univ, Bugwood
Nutsedge photo by Howard F. Schwartz, Colorado State University, Bugwood.org

4. This caller has a few walnut trees that the tops look good, but near the base of the trunk the tree is losing bark. He recently added some soil and river rock around the trees. Will the trees survive?

A. When adding soil and rock around a tree that had been planted for a while, it changed the grade around the trees. This can lead to many problems with the tree because it makes the tree too deep in the soil, especially after the roots were at a higher level in the soil for multiple years. This will lead to the death of these trees. The bark could be coming off because of the death beginning in the tree or it could be due to possible damage to the roots when the soil and rock was moved in. Either way, the trees will die. Enjoy them until they do or until they become a hazard to homes, cars, or people found underneath them.

5. What would be a good replacement tree for scotch and Austrian pines?

A. Diversity is a good thing to remember when planting a new trees. Diversity includes species and age of trees. This caller has a great deal of trees to replace in a CRP, it is advised to not replace all of these trees at the same time so they have a diversity of age as well. Good choices include Douglas fir, concolor fir, hemlock, eastern red cedar, blue spruce, black hills spruce, Norway spruce, and Ponderosa pines.

6. A caller has a windbreak with bagworms. Is it too late to spray this year? What should he spray with?

A. We should be ok in the window to spray for bagworms. It is best to spray after the bagworms have germinated for the year until when the bags have developed over 1 inch in length. Once the bags are larger than 1 inch long, the chemicals will not be very effective. Tempo or Bt products would be the best choices for control of bagworms, but most any general insecticide will work.

Bagworm4
Bagworm

7. This caller has a 20-year-old red maple that only has leaves on the west side to cover only 1/4 of the tree. What is wrong with the tree?

A. When that much of the tree has died back, it will not recover. It should be removed to reduce the hazards that will appear from a dead tree.

8. A caller has a newly planted blue spruce. How long should they maintain watering the tree? Should it continue through the winter months?

A. Newly planted trees should be watered throughout the growing season, and even during the winter. If we don’t have a lot of snow cover through the winter months, it is important to water an evergreen tree about once a month on a warmer day. When watering in the winter, water in the early to mid-day to allow all of the water to soak into the soil rather than freeze up on top. It would be best to continue watering this tree at least for 3-5 years on a regular basis. However, even a 30-year-old tree needs to be watered some in years of drought. It would be best to always continue to water this tree, even if only sporadically.

9. This caller wondered if adding drain tiles when adding a raised bed around an established tree would help it to survive with this practice that is not recommended?

A. Adding a raised bed to an existing tree is not an issue with drainage. Adding more soil to where a tree is already living can decrease the amount of oxygen that the roots are able to get which can then kill the tree. Also, adding this soil make it so that the trunk of the tree is underground which can decay the trunk and lead to crown rot or other bad conditions that also lead to death of the tree.

10. A caller has a pin oak that the roots are starting to pop out of the soil around it. What can be done for it?

A. Wood-chip mulch can be used to cover up the roots as they show up out of the soil. Do not add soil or increase the soil level. Avoid rock mulch as it can be too hot for the plant. Adding a mulch over the roots will prevent you from mowing over the roots and injuring them. Plants can be planted among the roots as well, but don’t add soil to do that.

11. Is it too late to prune lilacs?

A. Lilacs will begin producing flower buds for next spring shortly after they finish flowering this year. They should be pruned within a couple of weeks after blooming has finished in the spring. They can be pruned this late, but it will reduce the flower production for next year.

12. This caller has lilacs that have never been pruned for many years. How, when, and how much can she prune now?

A. A rejuvenation pruning may be beneficial for this situation. Older lilacs, if never pruned, have unproductive wood. This will lead to less leaf production, less flowering, and often much of the leaf and flower production will be just at the top 1/3 of the plant. When this happens, it is best to just prune the lilac off 6-8 inches above the ground to allow it to regrow with younger, more productive wood to produce more leaves and flowers throughout the whole plant. Rejuvenation pruning should be done just after flowering or in the fall for best health of the plant.

13. The last caller of the day wants to know about planting and growing blueberries and currants in Nebraska. He has pots he wants to plant them in to plant the pot into the ground. Is that necessary? What type of soil should be used?

A. Blueberries are not the best option for Nebraska soils. They must live in highly acidic soils, which we do not have. If determined to grow blueberries in Nebraska, it is best to grow them in a pot in the ground that can be brought up every year to amend the soil with acidic fertilizer or peat moss. Serviceberries may be a better choice to blueberries for Nebraska. Serviceberry is a native plant so it will grow in our natural soils with a lot less care and they have more antioxidants than blueberries do. There are also some newer varieties that have berries larger than blueberries. Currants will grow just fine in our natural soils and need no ammendments.

Yard and Garden: June 2, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for June 2, 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: Graham Herbst, Community Forester from the Nebraska Forest Service

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

1. The first caller of the day has a Hen and Chicks plant that has grass growing in it. What can be done to remove the grass? She also has spiders in her lawn, what can she do to control them?

A. Grass-B-Gon is a product that contains the active ingredient Fluazifop. This is a grass herbicide. This product or any others containing Fluazifop can be sprayed directly over broadleaf plants with no damage to the desired plant. The spiders are not an issue outside in the lawn, in fact, they are beneficial. Spiders in the lawn are feeding on insects, many of which cause problems to our plants or bother us. Outside, spiders are beneficial. To keep them from coming indoors, home barrier sprays or tempo can be used around the foundation of the house to keep spiders and insects outside. If there is a fear of spiders, the tempo could be used where the spiders are seen.

2. A caller has a mock orange that has not bloomed for the past few years and now this year it finally is blooming some. Should it be removed? Why hasn’t it been blooming?

A. This could be due to a maturity issue. Many of our woody plants need to become established and get to a certain age before they will begin blooming. It could also be due to pruning time. Mock Orange bushes need to be pruned right after they finish blooming because they bloom on last years growth, or old wood. If they are pruned in the fall or early spring, the blooms would be cut off.

3. When is the proper time to spray for bagworms on blue spruce trees?

A.Spray when the bags are small to get the best control. It is best to spray after the bags emerge in the late spring to early summer but before the bags get longer than 1 inch in length. Mark a branch with a bag on it now and keep checking it to determine when the bags have emerged.

4. A caller has 6 table grape plants that had grapes set on. Now the grapes are dropping off and 70% are gone from the plants. What has caused these plants to loose all of the grapes?

A. This could be due to frost damage. Here is a guide from Oregon State University to describe the many factors that can hinder fruit development in grapes.

Forsythia-Richard Elzey, Flickr
Forsythia, Flickr image courtesy of Richard Elzey per CC license

5. Is it too late to prune forsythia this year?

A. It is too late to prune and not cut off any blooms for next year. Spring blooming shrubs should be pruned shortly after they finish blooming for the year. Forsythias bloomed in March this year, so it would already be starting the formation of flower blooms for next year, pruning them now would cut those buds off. If the intent is to just prune a few branches just a little, it wouldn’t impact the overall blooming of the shrub, but pruning too heavily will lead to little or no development of flowers.

6. A caller wondered where they could go to find the wrap around water bags for trees?

A. Local nurseries should carry them or there are many online locations where you can order them. These bags are beneficial to help keep the root ball moist to help get new trees established.

7. Can Grass-B-Gon be used in strawberries or phlox and will preen reduce the number of runners grown off of strawberry plants?

A. Grass-B-Gon is not labeled for use in fruit bearing tree crops and vines. So, it cannot be used in strawberry plants. It would be good to use for grasses growing in phlox and not cause any harm to the phlox. Preen stops the germination of seed to reduce weeds grown from seed in the garden, so it will not harm runners which are growing off an existing plant, not from seed. Check to make sure the preen you are using is labeled for use in strawberries, the general preen is not for use in vegetable gardens.

8. How do you transplant a wild rose?

A. First, make sure it is on your property. Then, just make sure you dig up as much of the rootball as possible and replant it right away. You could also try taking a cutting from one of the branches and dipping it into rooting hormone and placing it into a pot of gravel to get roots to grow. Once roots develop, you can plant the rose.

9. A caller wants to build a privacy border with shrubs. Would Burning bush work for this or are there other options to choose from?

A. Burning bush would be a great privacy wall with good fall color. Other shrub choices would include serviceberry or any of the viburnums. You could plant it now, just make sure the plants get plenty of water with it being this hot and the roots being minimized due to transplanting.

10. This caller has tomato plants that when they planted it they saw grubs and wireworms in the soil around it. Should they treat for this and if so, what should be used?

A. Grubs are not controlled effectively around vegetable gardens because the chemicals with the best control are not labeled for use in the vegetable garden. However, there is a fairly high threshold of grubs and wireworms in the garden before damage is too high. A few grubs or wireworms throughout an entire garden will not cause any real damage. The plants they are most problematic on would be the root crops such as potatoes.

11. This caller had 2 questions: Her asparagus has been planted in this location for 30 years and is quite spindly, why is that? Her peonies are done blooming now, can she deadhead the spent flowers?

A. The asparagus is regularly fertilized so the small spears could be due to heavy harvest or it could be getting old or too crowded. It would be time this year to stop harvesting to allow the plants to recover and make sure to stop sooner next year. Once peonies and iris plants have completed their blooming period, the flowers can be cut off and composted. Leave the leaf material on the plant to build sugars to help with the flowering next spring.

12. How do you control weeds in asparagus?

A. Hand pulling and mulch would be the best options for weed control. When the plant is done in the fall and the leafy material is all removed below the ground level, the existing weeds can be sprayed with Roundup as long as no green material from the asparagus is above ground or showing. Here is a good explanation from Backyard Farmer of why we don’t use salt on asparagus for weeds and how to effectively control weeds with Roundup.

Carpenter Bee, J. Kalisch
Carpenter Bee photo from Jim Kalisch, UNL Entomology

13. A caller has carpenter bees digging holes into the roof of a patio. What can be done about this?

A. You can plug those holes with caulk or putty or use a sevin dust in the holes. For more information on Carpenter Bees, see this article from Retired Extension Educator, Barb Ogg

14. This caller has puncture vine in the lawn. What can be used to control it?

A. 2,4-D is a good way to control it in the the spring before it blooms.

15. A caller has peonies that need to be transplanted. Can they also be divided when they are transplanted?

A. Yes, they can be cut into a few pieces when they are transplanted this fall. Just make sure that each section you cut off the plant has 3-5 eyes which are more like pink noses or knobs on the roots of the plant. Peonies are best transplanted and divided in September or October.