Yard and Garden: June 23, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for June 23, 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 Hosts: Mike Onnen, Manager for the Little Blue NRD & Donnie Engelhardt, Assistant Manager for the Little Blue NRD

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 wanted to know if it was time to spray for bagworms yet this year and what to use for bagworms?

A. Yes, the bags have emerged. There is time for a couple of weeks yet to get them sprayed, just 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.

Bagworm4

Bagworm

2. A caller has 2 large oak trees that when he parks his truck underneath it gets sticky from the aphids in the tree. What can be done to manage these?

A. The aphids are producing honeydew as an excretion and they do feed on the oak trees, but often this is not that damaging to the tree. You can spray for the aphids in the tree with a general insecticide, but if you give it a little time predatory insects will come in and kill the aphids. If you spray, you will kill the predators as well as the aphids. It is often not necessary to spray for aphids in a tree.

3. This caller has lilies that have grown too thick in her one garden bed. When can she divide these to transplant some in a new location?

A. This could be done this fall or you can wait and thin the lilies in the spring as well, either would be fine. I would advise against transplanting and dividing plants this time of year because in the heat, the plants don’t have enough roots to get to more water to keep them cool.

4. A caller has a weeping willow that has many leaves turning yellow and the tree is thinning. What would be wrong with the tree and how can it be managed?

A. This tree is likely dealing with environmental stress. There are not spots on the leaves to indicate a disease or damage that would be from insects. After viewing the photos, it is determined it could be due to improper planting as it looks too deep with no root flare. There may be stem girdling roots that would not be evident for a few years after planting.

5. How do you control ground squirrels in your yard?

A. There is a great publication on Ground Squirrels from the Internet Center for Wildlife Damage Management which shows how to set a trap for ground squirrels.

6. A caller has Iris, yucca, and prickly pear cactus that are all getting many weeds growing in and around these plants. The weeds include both grasses and broadleaf weeds. How can the weeds be controlled without injuring the desired plants?

A. The grasses can be sprayed with Grass-B-Gon or another similar grass herbicide. Unfortunately, there isn’t a selective herbicide that will kill broadleaf weeds and not kill broadleaf desired plants. For the broadleaf weeds, the best defense is to hoe the weeds out and mulch the garden in the future to hold the weeds back.

7. This caller has a plum hedge that has holes in most of the leaves throughout the hedge. The holes form initially as a brown spot and then a hole appears. What would cause this?

A. This is likely due to herbicide drift. There is no control for that, but if it is minimal it shouldn’t impact the hedge too much. However, multiple years of herbicide drift to the same plants can start to stress and in some cases kill the plants.

8. A caller has onions that have formed a soft, brown spot on the onions when they were dug recently. What would cause this?

A. This is likely a rot issue that developed from a pathogen in the soil. It is always best practice to rotate the crops. Also, ensure that you properly cure your onions before storage.

9. How can you control sandburs?

A. Crabgrass control in the spring will work for sandburs as well as foxtail and crabgrass. All of these are annual grasses.

10. A caller has tried to plant roses in the same location for a couple of years now and it seems like they grow to about 18 inches, bloom, but then die over the winter months. The are planted in a garden with rock mulch, watered with a bucket of water as needed, and were pruned off in March. Why can’t the caller get the roses to live longer than one year?

A. This sounds like mostly environmental stress to these plants. Rock mulches are hot and absorb no water, switch to a wood chip mulch to cool the roots and hold moisture. Watering should be done with a soaker hose or other type of sprinkler system. When a bucket of water is poured over the plants as needed, the water fills up the top pores of the soil surface quickly and then spread out rather than down. A slow trickle on the plants for a while each week to wet the soil down to about 6-8 inches will be more beneficial. Pruning of roses is best done in the middle of April once growth has begun further to ensure healthy wood is not also removed with the dead wood too early in the spring. Add extra mulch around the plants in the winter months, up to 4-6 inches deep in the winter months, then spread the mulch out to 2-3 inches deep during the growing season. Extra mulch in the winter will help protect the plants from inconsistent temperatures in the winter.

11. This caller wants to know when to dig up garlic? He also wants to know if bleeding hearts can be cut back now?

A. Garlic should be harvested in July after 30-50% of the leaves have died back. Harvest during dry weather and leave the bulbs on the ground to dry for a week before storing. The flower stalks of bleeding hearts can be removed, but the leaves need to be left on the plants to build sugars for next years growth and flower production.

12. How can grasshoppers be controlled if they are in the flower garden?

A. Any general insecticide will work for grasshoppers in flower gardens. Sevin, eight, tempo, bifenthrin, and others will work for flowers. When treating grasshoppers, it is also important to treat the grassy areas of roadsides and ditches where grasshoppers are often found.

13. This caller has grass growing in his asparagus patch. How can the grass be controlled?

A. Hand pull and apply a mulch to the asparagus patch. The earlier you get the mulch applied in the season, the better the control will be. Also, after harvesting is complete, the asparagus can be snapped off below ground level and Roundup or another glyphosate product can be applied as long as there is no green asparagus above the ground.

 

Grasshoppers, J. Larson

The four main pest species of grasshopper in Neb. Top row two striped grasshopper adult, red legged grasshopper adult. Bottom row differential grasshopper adult, migratory grasshopper adult.

14. How can you control grasshoppers in the vegetable garden?

A. Sevin, eight, and bifenthrin are labeled for use in the vegetable garden. Also, remember to treat for grasshoppers in tall grasses along roadsides and ditches. Follow the PHI (pre-haravest interval) to know how many days after application necessary to wait to harvest the vegetables.

15. A caller wants to know when to transplant peach trees?

A. Fall or spring are both good times to transplant any trees.

16. The final caller of the day has a pond with moss or duckweed in it making it cloudy. What can be done to clean up the water?

A. Avast SRP is labeled for Duckweed and Copper sulfate can be used for Algae.

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Yard and Garden: June 3, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for June 3, 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: Sarah Browning, Lancaster County Extension

1. The first caller of the day has strawberries that are all developing but they are rotten fruits. What would cause this and can it be fixed?

A. This is probably due to a fruit rot disease that is caused by a fungus due to the high rains this year. At this point in the season, fungicides will not help and you will not get much of a crop from these plants. If this is a problem seen every year, a liquid copper fungicide can be applied next year. You should start spraying the plants at petal fall right after the blooms finish next season. To help with this disease, also use a mulch around the plants and avoid overhead irrigation.

2. A caller wanted to know if wildflowers do better where grass doesn’t grow very well? Can he still plant wildflowers now?

A. Wildflowers don’t really do better where grass won’t grow, but the area to plant wildflowers does need to be prepared for the wildflowers. It is best to clean up the area with a glyphosate product, such as Roundup, then till the area up and seed the wildflowers. This can still be done now, it will be fine through most of the spring and fall months. Unless you are planting annual wildflowers, which will reseed for each year, you will not get many blooms this growing season. It will take a few years to get the wildflowers going well and weed control will be necessary. If you don’t want any grasses growing in the wildflower patch, you can use grass herbicides and not harm the wildflowers.

3. This caller has pansies that are being eaten, the small white dots are on the underside of the leaves. What would this be and how can they be controlled?

A. This could be aphids which can be controlled with eight, bifenthrin, or malathion. However, pansies are nearing the end of their life as they are a cool season plant. So you could just remove the pansies and plant something else to reduce the problem and not have to use pesticides.

4. A caller has been dealing with high populations of grasshoppers recently. They are feeding heavily on his potatoes. What can be done to control them?

A. In the potatoes, you will need to use an insecticide labeled for use in a vegetable garden such as bifenthrin, sevin, or eight. It would also be helpful to keep the grass mowed around the garden and to treat it with some of these insecticides. Also, grasshoppers are often found in roadsides, so be sure to spray these areas as well to help reduce the overall population.

5. When can peonies and iris be cut back?

A. You can cut off the flower stalks on both of these plants as soon as they are done blooming. However, you need to wait until they die back in the fall before removing any leaves from the plant.

6. This caller has a lawn with patches of darkened areas throughout it. What would cause this?

A. Walk through the dark areas to see if the blades pop back up. If the blades stay down after they are walked on and you can see you footprints, it is due to drought stress and the lawn needs to be watered. Also, look closely at the leaf blades to see if there are small, black/gray structures like tiny balls. This would be slime mold which is also showing up in the lawns now. Slime molds are not a serious problem to the lawn.

7. This caller has a weeping willow. He wants to know if he can prune the branches up so he can mow underneath it?

A. Pruning for a weeping willow is best done in the fall but it can be done now. You can limb it up and shorten some of the branches to make it more accessible for mowing. However, don’t remove more than 1/3 of the plant in one growing season.

8. A caller wanted to know about mosquito control. He had found a recipe online that was with household items and it claims to control mosquitoes for 80 days. Will this work?

A. No. The best control for mosquito control outdoors only last for a few days. It is best, if you are having an outdoor BBQ, to spray the lawn and shrubs around the lawn up to 2 days prior to the event for management of mosquitoes. You can use sevin or eight or malathion or bifenthrin for control. Be sure to use bugspray containing DEET while outdoors. Also, make sure you have no standing water in your lawn to reduce the population of mosquitoes.

Roseslug Collage

Rose slug on the leaf on the left, damage from rose slugs on the right.

9. This caller has roses that have leaves that look shredded or with many holes in them. What can be sprayed on the roses to help them with this problem?

A. This was brought into the extension office later for identification. It was rose slugs. These are small, translucent, green caterpillars with a brown head found on the underside of the leaves. Rose slugs are actually the immature of a sawfly and not a slug at all. They are mostly damaging to the aesthetics of the plant and are not that harmful but they can be treated with sevin dust on the underside of the leaves if they are heavily damaging the plant. Be careful to not get the sevin on the flowers to not harm bees.

10. What digs holes 6-7″ deep straight down into the mulch around trees?

A. This could be either squirrels or skunks or possums that would be digging for insects. Clean up around the tree to help deter the animals.

11. The final caller of the day has a cedar windbreak with a lot of scrub trees growing among the cedars. How can those be controlled?

A. It is best to just cut off the scrub trees and do a stump treatment with a concentrated roundup product. Spraying in the windbreak can damage the cedar trees.

Yard and Garden: May 27, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for May 27, 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: Dick Campbell, Owner of Campbell’s Nursery in Lincoln

1. The first question of the day came via email. A listener wanted to know how to control clover in their lawn?

A. Clover is best managed in the fall months when it is pulling nutrients from the leaves into the roots, it will take the chemical into the roots as well. Products with triclopyr work best, but 2,4-D will work as well. Make 2-3 applications in September and October for best control.

Mallow, Phil Westra, Co State Univ, Bugwood

Common Mallow photo by Phil Westra, Colorado State University, Bugwood.org

2. A walk-in question was for identification of a weed.

A. This weed is mallow. It is a difficult weed that will move throughout our gardens. It can be controlled with a careful application of Glyphosate (Roundup). Be careful not to spray any other plants with the glyphosate product.

3. A caller wanted to know when she can transplant daylilies and Iris?

A. The daylily could be transplanted now. It would be best to move these in the spring or in the fall, but daylilies are a tough plant and would be fine if moved now as long as they are kept well watered when it is hot because the root system isn’t developed at the new location yet. Iris would be best if transplanted in the fall.

4. A caller has earthworms making his lawn uneven. What can be done to control those?  This caller also wanted to know if he can water houseplants with water that goes through a water softener?

A. Earthworms are very beneficial to our soils as they reduce compaction and add organic matter back to our soils. The damage from them is only seen for a couple of weeks in the spring with rains. If you can deal with it for a short time, it is best to avoid treating for them. If you have to treat, Sevin insecticide does have some management capabilities for your lawn. As for watering the houseplants with water from a water softener, it is best to use water prior to the softener due to the increase of salts in the water.

5. This caller wants to know how far away from the house a shade plant should be planted? She also wants to know how she can manage grass in Iris’?

A. Spacing the tree from the house depends on the tree chosen and what the full size of that tree is. For many of the oak or maple shade trees, it is best to go 25-35 feet or farther from the house to ensure no problems develop as the tree grows. The grass in the Iris bed can be controlled with Grass-B-Gon.

6. A caller has a cherry tree that the top broke off but it is still attached to the main trunk. Can it be saved?

A. There is no way to re-attach a broken off branch. This branch will have to be removed. Because this is the only branch that is still producing leaves and cherries, the tree should be removed and replaced.

7. A caller has 2 rhubarb patches that were damaged badly by hail. The leaves look terrible. Should those leaves be removed or left on the plant?

A. If there are new leaves growing below the damaged leaves, the damaged leaves can be removed. However, if those damaged leaves are all that is alive on the plant right now, they should be left on the plant until new leaves begin to grow so that the plant can still grow and build nutrients for next spring.

8. A sample was brought in of a trumpet vine with many little insect all over the stem, leaves, and flowers. The plant has been sprayed with Sevin with no control. What can be done for this trumpet vine?

A. Sevin is not an effective method of control for aphids. In high populations you can use Eight or Malathion. Aphids are not very damaging to our plants and they are fairly short lived. Given time, predatory insects will move onto the aphids to control them without chemicals.

9. This caller was looking into planting apple trees and found there is a disease called cedar-apple rust. Is this a concerning disease here and what should be done to avoid problems with it?

A. Yes, cedar-apple rust is a damaging problem for apple trees. The spores can spread up to 2 miles, so it is best to plant a resistant apple tree cultivar. It is also good to look for cultivars that are resistant to apple scab. For choosing your cultivar, here is a publication from Purdue that lists common apple tree varieties and their disease susceptibility: Disease Susceptibility of Common Apple Cultivars

10. A sample was brought in of a tulip tree with leaves that are puckered and rolled downward. What would be the problem with this tree?

A. This tree has aphids on the underside of the leaves that are sucking the juices out of the leaves. Aphids are not terribly damaging to our plants and are fairly short lived. In high populations you can use Eight or Malathion.

11. Is there a dry granular weed killer for the lawn? When is the time to move gooseberries, iris, peonies, and rhubarb?

A. Fertilome is a good dry, granular weed killer. This is best applied early in the morning so it will stick to the leaf blades with the morning dew. Gooseberries should be moved after dormancy. Iris and peonies should be moved in the fall, typically in September when the tops begin to turn yellow. The rhubarb should be moved after they are dormant in the fall or early spring.

12. This caller has asparagus that has been planted in this location for many years and is now dying out. She fertilizes 2-3 times per year with a general fertilizer. What is causing this problem and can it be fixed? She also wants to know if she can use canning salt or Epsom salt in her garden? And, finally, she wants to know what to do for the aphids on her honeysuckle?

A. Asparagus will die out due to age. It would be beneficial to dig it up this fall after it goes dormant and divide the plants to replant as individual clumps. When replanting, sprinkle some bone meal in the hole to help with fertility. As for using epsom salt in the garden, this is not necessary. Epsom salt is magnesium sulfate which is in good supply in Nebraska soils. If nutrients are necessary in your garden, it is best to use a general purpose fertilizer. Canning salt can harm your plants and damage the soil. It is not a recommended practice to use any type of salt in your garden. As for the honeysuckle aphids, those should be controlled with Eight or Malathion. The aphids on honeysuckle can cause witches broom to the plant so they should be controlled.

13. Do raspberries and blackberries need to be grown on a trellis?

A. Yes, a trellis or an espalier would be a good way to grow them. Here is a good guide to growing raspberries and blackberries from Missouri Extension

14. Can red and black raspberries be planted together?

A. Don’t plant them within 20 feet of each other or they will cross pollinate and the fruits will not taste as good.

15. A caller has rhubarb that is shooting up stalks with seeds on them. What should be done with those?

A. Those seed stalks should be removed. Cut the stalk off at the ground. If left the plant will put energy into producing seed that should be stored for leaf and stalk production.

16. The last caller of the day has a mandevilla plant that is growing outdoors in a pot with a trellis. The leaves are now turning yellow and black. What is causing this and how can it be managed?

A. This is a moisture issue. The heavy rains this year are causing a leaf fungus to occur. A rose and flower systemic containing a fungicide can be applied to the plant to help reduce the disease.

Yard and Garden: July 3, 2015

Yard and Garden Green LogoThis is the Q&A for the Yard and Garden show for July 3, 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: Julie Albrecht, Professor in Health and Nutrition Sciences at UNL

1. A caller had a Bradford Pear tree with brown limbs on approximately 1/4 of the tree. What would be causing that?

A: This is probably due to fireblight which has been very common in many of our fruit trees this year, including pear and crabapple. If that is the case, prune out the infected limbs by cutting 6-8 inches behind the change in color on the branch from brown to black. Dip pruners into bleach water between each cut to reduce the spread of the disease through the tree.

2. The first caller also has moles in her yard, how can she control them?

A: Moles can be controlled by trapping. Find an active run by tapping the mounds down a few times prior to placing the trap in the run. If the mound returns each time it is knocked back into the hole, it is active and the mole will come back after the trap is set. For more information see the Moles publication from the Internet Center for Wildlife Damage Management.

3. A caller has a pond that has a lot of moss. How can this be controlled?

A: Copper Sulfate Crystals will work best on algae/moss. It is best if it is applied when the growth first becomes visible.

Photo by Howard F. Schwartz, Colorado State University, Bugwood.org

Nutsedge Photo by Howard F. Schwartz, Colorado State University, Bugwood.org

4. A gentleman wanted to know how to control nutsedge?

A: The best control for nutsedge is Sedgehammer, a product that is specific to sedges. It needs to be reapplied throughout the growing season to small plantings before they produce new nutlets that will produce more plants.

5. A gentleman has an ash tree that has many shriveled leaves with insects on the underside of the leaves. What can he do to control these insects?

A: These are probably lacebugs or aphids. Use a general insecticide such as sevin, eight, or malathion to control these insects on the ash tree. Lacebugs and aphids suck the juices out of the tree which will cause discoloration and curling leaves.

6. A lady has tomatoes that are curling and shriveling, she didn’t notice any insects or spots on the leaves. What would be causing this?

A: This could be possibly a virus or 2,4-D drift. If it is herbicide drift, the plants will grow out of it eventually and the new growth should be normal. If it is a virus there is no cure and the plant will continue to grow abnormally.

7. A lady has a mandevilla plant that has leaves that are turning yellow with spots. What would cause this problem?

A: This could be due to environmental factors such as high moisture early in the growing season or due to a fungal leaf spot. Ensure that the plant is getting the correct amount of moisture at all times. Use a fungicide on the plant to help with a fungal disease, Daconil is a good choice for fungicide.

8. A gentleman is curious about vegetable preservation techniques. Do you have to blanch all vegetables that you will be freezing and will you lose nutrients when you blanch these vegetables?

A: Blanching is necessary for all vegetables to stop growth and stop enzyme production that can cause the vegetables to lose flavor. Blanching also helps maintain the freshness and color in your vegetables. Blanching only needs to be done for a very short period of time, followed by plunging the produce into ice water to stop the cooking process. After it is drained, the vegetables can be put into freezer bags for freezing. For more information regarding food preservation, visit the National Center for Home Food Preservation for the safest recommended procedures for food preservation.

9. A lady has some trees that have been planted in the past couple of years and now it looks as if something has come and eat the top off of the trees. Now there is suckering at the base of the plant. What would have chewed on these trees and can those suckers be used to grow a new tree?

A: Deer is likely the culprit for chewing off the trees. The best control for deer would be to add some type of fencing to exclude deer from the trees. The suckers are coming up at the base of the plant because the top has likely died back which forced the trees to produce suckers for new growth. The suckers may be weak or not grow straight, but with additional help a new tree may be able to regrow from the suckers. It might be best for new trees to be planted for best growth and strongest trees.

10. A caller dug out their pond and moved some of the soil to a garden spot. The vegetables growing there are growing but have no fruits on them. What would cause this?

A: This is likely due to high nitrogen that came from the soil at the bottom of the lake. Nitrogen is a nutrient that will cause green leafy growth that can sometimes suppress vegetable production. I would suggest a soil test to determine what to do with the garden to help production improve.

Roseslug Collage

Photo on the left of the roseslug on the underside of the leaf, Photo on the right of the damage from roseslugs

11. A caller has roseslugs on his roses. They have destroyed about 80% of the leaves on the plant. What can be done about this?

A: If a roseslug population is low, control is not necessary. However, this sounds excessive so a controlling spray with a general insecticide such as Eight will work for these roseslugs. Be careful to not spray the rose flowers to reduce impact on pollinator insects.

12. When is the best time to transplant Iris’?

A: Fall is the best time for transplanting Iris and Peonies. Transplanting now would be difficult because when they get moved they have limited roots and in the hot, dry part of the summer it would be hard to keep the plants hydrated enough to keep it alive.

13. A caller has cherry trees that have much of the cherry crop as rotten fruits hanging on the trees. What would cause this?

A: This is brown rot, it is a fungal disease that is common in cherry trees this year due to the wet spring. There is no control for it at this time. Fungicides should be applied early in the spring to prevent this disease.

14. A caller has a cherry tree that one side of it has died. What has caused this problem? He did have some damage occur to the trees a few years ago due to cattle foraging through the area.

A: The cattle likely injured the bark of the tree causing it to get a canker on the trunk. The canker would cause a disruption in the flow of water and nutrients throughout the tree. There is no cure for the canker. He can try to prune out the dead branches and see if it will come out of it in the next couple of years.