Yard and Garden: June 8, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for June 8, 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: Donnie Engelhardt, Assistant Water Resources Director, Little Blue NRD

1.The first caller of the show heard of a chemical that can be used to treat bindweed that started with a Q. What is that product?

A. Quinclorac is the active ingredient in a product called Drive. It is effective at controlling bindweed. However, this product is only labeled for use in lawns and cannot be legally or safely used in landscape beds or vegetable gardens.

He also is having a problem with his peach tree, it didn’t leaf out on the one side. The damage is also seen in some hydrangeas planted nearby. What is causing this?

A. This could be due to herbicide damage. If multiple types of plants in different families, genus’, and species are all affected the same it is often due to herbicide drift. There is nothing that can be done now to fix the problem, leave them to see if they grow out of the damage.

This first caller’s final question is that he has 3 pear trees that he ordered from a mail order catalog and one has not leafed out still. Is it dead?

A. This one that died could have dried out during transport. I would assume by now it would have leafed out if it was still alive. Scrape the bark off some of the smaller branches, if they are green there is still life in the tree, if it is brown, the tree is dead. Also, if the branches bend rather than break they are still alive.

2. A caller is looking to plant some new trees for shade, preferably something fast growing. When should they buy and plant these new trees?

A. Purchase your plant material when you are ready to plant. If the plant has to sit in the pot longer, it can lead to more problems with it drying out. The best times to plant a tree would be either in the spring or fall. At this point, it would be best to wait until fall, like September – later October. Planting now would be difficult to keep the tree watered through the heat/drought of the summer. Fast growth is not always the best option. Fast growing trees are not as strong as the slower growing trees and tend to break more in storms. Slower growing trees can actually put on quite a bit of growth in a few short years if they are kept with a 2-3 inch mulch ring and kept well watered. For good tree choices, view this guide from the Nebraska Forest Service.

3. This caller has Iris’ that have finished blooming, can they be cut back now? They also have some mums that died over the winter, why is that?

A. Once Iris’ and peonies’ have finished blooming for the year, the flower stalk can be cut off at the ground level. However, the leaves need to be left there to build energy in the roots for next spring. Some mums are just not as hardy as believed. Many gardeners struggle with maintaining their mum plants over the winter due to repeated freezing and thawing cycles through the growing season as well as wet, heavy soil or lack or snow cover. Longevity of the plants can be enhanced by planting them in a location that is more protected from north winds, discontinuing fertilization by the end of July to reduce new growth at the end of the season, adding several inches of mulch to the soil around the plants through the winter months, and cutting the plants back in the spring rather than in the fall.

4. Should the blooms of small tomato plants be pinched off?

A. Removing those blossoms until the plants get a little more growth on them will help the plants develop more roots and more shoot growth before pushing so much energy into producing the fruits. Wait until they get a little bigger before allowing those flowers to develop into fruits.

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Redbud Tree

5. A caller has a redbud tree that was planted last year and has not leafed out yet this year. It is, however, producing suckers at the base of the tree. Can those suckers be grown into a new tree? Also, how should trees be fertilized?

A. This could be a winterkill issue. Be sure to purchase redbuds from a local source. Often box stores purchase redbud trees from a Southern source and send them to all stores in the United States. If a tree was started further south than where it will be planted, it will not adjust well to the change in climate from the south to here. The sucker will grow into a new tree. Redbuds will do better with this than some. Often the suckers from a tree may not be as strong as the main tree and will not do as well, but with a redbud it should be fine. Fertilizer is rarely needed for trees in Southeast Nebraska. I would especially avoid fertilizer on a stressed tree, such as this redbud. Fertilizing a stressed tree will lead to further stress.

6. When is the best time to prune suckers from the maple trees and when is the best time to prune the lower branches from a spruce tree so the mower can fit below it?

A. Anytime is a good time to prune suckers from a tree. It is best to just continually prune them off as they form. If you leave them, they take energy from the tree. You can prune spruce trees most anytime of the year. However, if you are just looking to prune them so you can mow under the tree, if you leave them the tree will provide it’s own mulch and the grass will not grow under the high shade of the tree.

7. This caller wants to know what to do with peonies now and if ants are needed for the flowers to open on a peony?

A. At this point with a peony, cut off the stalks of the flowers and leave the leaves there. The leaves should be left to grow and produce energy for the plant so it can come out and flower early next spring. Leaves of peony plants can be removed in the fall when they turn brown and die back naturally. No, ants are not necessary for the buds of peony flowers to open. That is just a myth because ants are commonly found on the flowers, but they just like the sweet nectar.

8. A caller planted mums last year, they looked great through the season. This year only 2 came back. What is wrong with them?

A. Some mums are just not as hardy as believed and they often die due to winterkill. Many gardeners struggle with maintaining their mum plants over the winter due to repeated freezing and thawing cycles through the growing season as well as wet, heavy soil or lack or snow cover. Longevity of the plants can be enhanced by planting them in a location that is more protected from north winds, discontinuing fertilization by the end of July to reduce new growth at the end of the season, adding several inches of mulch to the soil around the plants through the winter months, and cutting the plants back in the spring rather than in the fall.

9. The last caller of the day has peppers planted in a mineral tub that are looking wilted. They are green and growing well but have droopy leaves. What is wrong with them?

A. Through discussion, it was noted that these peppers are planted in a container with soil from the backyard, not potting soil. It would be best to use a soil mix rather than soil from the ground. Potting soil has more nutrients available and is more porous for better plant growth. Adding fertilizer to his plants may help.

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Yard and Garden: May 29, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for May 29, 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: John Fech, Extension Educator in Douglas & Sarpy Counties

1. A caller had fine webbing on her tomatoes, what is it and how can it be controlled? She also wondered about using blossom set on her tomatoes?

A: The fine webbing on the tomatoes would be spidermites. These can be controlled with a strong spray of water on the plants to knock the mites off and kill them. As for the blossom set, is not recommended as it does not have strong research to back the effectiveness of it.

2. A lady had a river birch and a dogwood shrub that are not leafing out at the top. Why is this?

A: The plants are going through environmental stress. This spring has been warm followed by very cold to warmer again and now just cool, cloudy, rainy weather. That follows 3 years of stressful environmental conditions starting with the drought in 2015. Many of our plants are experiencing a degree of winterkill due to these events, where the top of the plant is not leafing out but the bottom of the plant is. Many of our plants will eventually fully leaf out or just have some dead branches through them. With the dogwood, those dead branches can be pruned back, but wait 2 more weeks to see if any more of the plant comes back. With the river birch, it is not advised to top a tree, so the pruning practices will be more difficult and it would be best to consult an arborist for that.

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3. A caller has an Austrian Pine where the new growth is browning and lighter green, whereas the rest of the tree is dark colored. What is wrong with it?

A: The needles at this point are not fully elongated due to the late spring events. Give the tree time to fully come out of the winter dormancy period to determine the color differences. If at that point there is still a problem, email me or your local extension office for more information.

4. This caller has a Japanese Lilac tree that has brown branches with no leaves on them. What should be done with those branches?

A: Scrape the branches with a fingernail or pocket knife to see if there is any green tissue under the bark in the cambium layer. If underneath is brown it is a dead branch. Either way, wait until around June 15 to see if the branches will come back from winter dormancy. If not, then the dead branches can be removed at that point. Don’t remove any live tissue from the tree at that time of the year.

5. A caller wanted to know if you can get multiple cuttings from a broccoli plant?

A: Broccoli is a tough plant to grow in Nebraska because in typical years it gets too hot too soon in the summer to provide an efficient harvest. It is suggested to grow broccoli as a fall crop. This year, however, is a good year for broccoli in the spring due to the slow warm up we have seen. As long as you only cut out the broccoli florets, you can leave the leaves and provide additional side buds that can be harvested for broccoli meals.

6. This caller has a large silver maple in their yard and now they are finding multiple small seedlings of maples all around their landscape. How can those seedlings be controlled?

A: Mowing them off is the best practice or pruning them out while they are small and easier to control. Do not spray them with any chemicals for control because they could be suckers coming up off of the roots of the main plant and any chemical applied to root suckers can kill the entire tree. These seedlings could also be from the seeds that fall from the trees in samaras that resemble helicopters, but determining the difference is very difficult and it is just easier to only cut the seedlings rather than treat them with a chemical and risk harming the main tree that is enjoyed in your yard.

7. This caller has cherry trees that have suckers coming out from the base of the plant. What can be done to control those?

A: These suckers will have to pruned off repeatedly with pruners not the lawnmower. They are attached to the main plant and any chemical attempts would harm and possibly kill the main cherry tree. Typically, trees will begin to sucker when they are stressed. Ensure that the tree is well taken care of and healthy by providing it with a mulch ring 2-3 inches deep and as wide as they can make it. Water the tree at a slow trickle for 30-60 minutes one time a week during the hot part of the summer and only once every two weeks during the spring and fall.

8. This woman was wondering if now was the time to prune her snowball bush that is just finishing up the blooming period? She also wanted to know if this was the time to apply weed and feed to her lawn?

A: Now would be a great time to prune that spring blooming shrub. The rule of thumb is to prune spring blooming shrubs after they finish blooming for the year and prune summer blooming shrubs late in the winter before growth begins for the year. Now is the time to fertilize your lawn, but avoid using weed and feed products. The problem with a weed and feed product is that the weed control part of that needs to stay on the leaves and the feed portion needs to stay off of the leaves. It is a better practice to fertilize the entire lawn with only a fertilizer and spot spray with 2,4-D products only on the weeds in the lawn.

9. This caller’s daughter lives in Lincoln where flooding was a problem and she has a drainage ditch that has caused water to sit and is now concerned with mosquitoes. What can be done?

A: If the water is stagnant and there is no way to remove the water, it is best to use larvicides that are found in mosquito dunks that can be purchased at many box stores and garden centers. These mosquito dunks are not harmful to other wildlife or people.

10. This lady has a tree that has deer rubs on it. She placed a tree wrap tube on the tree and was curious about removal of the tree wrap.

A: The tree wraps and tubes are a great way to keep deer from damaging young, thin barked trees. They should only be left on for the winter months and then removed during the spring and summer. If left on they can girdle the tree if it gets too tight on the trunk and it can be a location for insects and diseases to get into the tree.

tree wrapping

11. This caller has Ponderosa Pines that have brown needles that cover 80-90% of the tree. It is only a problem on 2 of the many Ponderosa Pines that are all planted together. They have been planted for about 5 years and have shown this browning over the entire tree for 2-3 years. What can be done for this problem?

A: This could be a root issue dealing with stem girdling roots or a watering issue. It is hard to determine, but might possibly be due to low watering. Water the plants slowly for 30-60 minutes weekly in the summer and once every two weeks during the spring and fall. These trees may not make it through, if it is a root issue digging them up after they have completely died would help solve the problem.

12. The final caller this week wanted to know how late in the season they should harvest their asparagus plants?

A: They do need a period through the summer to rest from being harvested so they can build sugars to help them get growing next spring. It is best to quit harvesting when the stalks develop ferns, when they get small and spindly, and/or when they get woody. This will give the plant plenty of time to recover from this years harvest and prepare for next years harvest.

Weather Effects on our Plants

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This year has been a bit unsteady regarding growing conditions for many plants. I have been getting a lot of questions regarding the death in many plants this spring and the lack of growth in many of our plants as well. I wanted to take this time to go over this issue with all of you.

This spring we have been seeing quite a bit of dieback on many different perennial plants and shrubs. Roses and spireas are suffering from what we call winterkill. Winterkill occurs commonly in the winter months when plants are exposed to cold, drying winds. The winterkill was extremely hard on these plants this year and has caused the tops of them to die. What we are seeing in our landscapes is plants that only have leaves at the bottom of the plant with no leaves and brittle branches at the top of the plant. Many other shrubs are experiencing the same problem. These dead branches can be pruned out of the plant. If the plant affected was a rose, it could have more problems if the dieback occurred below the graft union that many roses posses. If it died below the graft union, it should be replaced with a new rose.

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We are also seeing a great deal of loss in willow trees. Many willow trees, throughout the state, are dying entirely or losing the top or many branches throughout the tree. This is attributed to many years of tough growing conditions. In 2012 our plants faced severe drought and three weeks of temperatures in the 100’s. This is very hard on our plants and it takes 3-5 years of normal growing conditions for a plant to recover from a drought like this. This drought was followed by the winter of 2013-2014, which was very dry, cold, and windy. That winter caused many of our plants, especially arborvitae, to die due to the desiccation they faced. Finally, we have had a very uneven warm up this spring that followed a quick drop in temperatures last November, when temperatures fell to only 5 degrees Fahrenheit.

It is very hard on plants to go through so drastic extremes during their growing season and to have it hit them for multiple years at a time. This is the reason for so much death and dieback in so many different plants.

A lot of our plants are also very slow to warm up this spring. Butterfly bush, privet, hibiscus, and beauty bush have still not broken dormancy this spring. We at Nebraska Extension are suggesting waiting until the beginning of June before giving up entirely on these plants.

Many of our vegetable plants, if they have already been planted, may not be growing very well at this point. They are slow to grow well in this cool, cloudy weather. They will catch up when it warms up.

Keep an eye on all of your plants for diseases that are sure to be a problem with this weather. Leaf diseases and fruit diseases could be a problem this year as many are common in wet, cloudy weather. Watch leaves for leaf spots to remove those leaves as soon as you begin seeing a spot on them. When you need to water, be sure to water your plants from the bottom rather than overhead to reduce spreading these diseases.

Yard and Garden: May 22, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for May 15, 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: Kevin Korus, Diagnostician for the UNL Plant & Pest Diagnostic Lab

1. A caller with a river birch that is 5-6 years old was planted with 3 trunks and now it has 5 trunks. Should those be removed or will it harm the tree?

A: River birch trees are commonly grown as a multi-trunked tree. If additional trunks appear, they can be left on or cut off with no problems for the tree, as long as they don’t grow too large before they are removed. If the trunks to be removed have grown to be 1/3 of the tree or more or the trunks are 1/2 the size or larger than the main trunk, you would not want to remove these as that would be removing too much of the tree in one growing season and can cause more problems to the tree than benefits. If they are not in the way, I would suggest leaving all 5 trunks.

2. A gentleman wanted to know how and when to prune blackberries and raspberries. He has raspberries that have died from the top downward on some branches with green growth at the base of the plant. What should he do about this?

A: The top dieback would likely be due to water stress or winterkill which occurs during the winter months when we see little moisture. As for general pruning, there is a great guide from the University of Missouri Extension to describe the many practices of pruning brambles, Pruning Raspberries, Blackberries, Gooseberries, Currants, and Elderberries.

3. This caller has amaryllis bulbs that were growing great and now the leaves are starting to turn yellow. What is the cause of this and how can she stop it from happening?

A: This plant is likely in need of a fertilizer treatment. They should receive regular fertilization with a houseplant fertilizer. Also make sure that the plant isn’t sitting in water. Amaryllis plants should be watered when the top two inches of soil are dry to the touch.

4. This caller has Weigela ‘Wine and Roses’ that she had trimmed last fall. Now one of them is only greening up at the bottom of the plant, why is this?

A: This plant is suffering from winterkill. As long as the bottom is greening up, the plant should be fine. Those dead branches can be removed back to green growth or back to the ground if there is no green on the branch at all. Remember to keep plants watered on the warm days when we face a dry winter like we did last year.

5. This caller was curious about rhubarb. How long in the year do you harvest rhubarb in the year or can you continue to harvest all year long? When should they be transplanted? What do you do when seed stalks appear on the plant?

A: You can harvest the plant until the plant begins to produce slender stalks. After that the plant needs to be left alone to replenish the sugars and nutrients to continue growing and produce next year. The stalks can be cut off or they can be pulled off. When the seed stalks appear on the plants, they should be removed. The production of seed stalks takes energy from the plant to make the seeds rather than leaving it to produce leaves and the stalks. Transplanting rhubarb is best done in the spring of the year. Avoid harvesting for the first growing season after transplanting and only do light harvest in the second season. By the third season, harvest can resume as normal. This is to allow the plant to get a good root system developed before loosing much of its leaf area.

6. This caller has a pin oak tree that is 45 years old. He added a mulch ring to the tree recently and wanted to know if rock mulch or wood chip mulch is better for the tree?

A: Any mulch is better than no mulch. Wood chip mulches keep the roots cooler and hold in more moisture than the rock mulches, but the rock mulches will not blow away or need to be replenished each year like the wood chip mulches. Either way keep the mulch only 2-3 inches deep.

7. This caller wanted to know how far apart to plant her asparagus? She planted hers 1.5 feet apart, is this too far apart?

A: Asparagus should be about 6-8 inches deep and 12-18 inches apart. There isn’t a problem with planting it too far apart, the problem would occur if they are planted too close together. Plants not spaced correctly can lead to disease problems.