Yard and Garden: May 19, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for May 19, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Jim Kalisch, Insect Diagnostician for Nebraska Extension

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

1. The first question of the day was from a gentleman wondering how to tell when to water his self-watering containers? There is no viewer or gauge to show the water level on the outside of the container.

A. Because a self-watering container is continually watering the plants in it, it can always be refilled. In this case, this container will keep your plants watered for at least a week to two so, they should be refilled before they completely dry up. I would suggest refilling the reservoir every week to 10 days.

Bagworm4

Bagworm

2. A caller has bagworms in their cedars. What is the best way to see them before they get too big to treat?

A. They haven’t hatched yet this year. Mark the branch you have a living bag on with flag tape to check the same bag every week from now until they hatch. You can also place a few bags in a container and keep it in the tree to see when they hatch in the container. Wait a couple of weeks after the initial emergence to ensure that all of the bagworms have hatched before spraying. The bags in the shade will take longer before they hatch. Once they have hatched, Bt is a good insecticide to use when they are young or you can use a product containing bifenthrin in it for longer lasting control.

3. This caller is wondering what types of problems we can expect in the garden, lawn, and trees this year due to the excess rain?

A. The rains in the spring tend to lead to more fungal diseases this time of the year, but they are not terribly harmful and many should fade out as the summer heats and dries up. Many things to watch out for would include fungal diseases in the lawns and trees. We are already seeing Peach Leaf Curl, different fungi in blue spruces, anthracnose on the leaves, and mushrooms popping up in our lawns. We will also see more problems from earthworms and fungus gnats which are mostly nuisance problems.

2015-09-22 18.45.39

Squash bugs on a zucchini

4. How do you effectively control squash bugs in the vegetable garden?

A. Squash bugs are difficult to control in our cucurbit vegetables including zucchini, squash, pumpkins, gourds, melons, and cucumbers. The best option is to kill the adults when they first emerge to manage the population before it explodes. Watch for the eggs as they develop on the underside of the leaves to destroy them before they emerge. Switch to other chemicals for management besides just using “Sevin” for control, which they are becoming resistant to. There are also lures that can be used for them which might help early in the season.

5. A caller has an Oregon Trail Maple that leafed out early this spring. Now the leaves are slightly cupped and turning yellow along the edges. What would be causing this?

A. This sounds like frost damage. If the leaves came out early, they may have been nipped by a light frost in late April. We are seeing this problem throughout many trees and shrubs this spring. The leaves may drop entirely from the tree, but the tree will then push secondary buds to produce new leaves that are not injured.

6. This caller wants to know how to propagate a lilac and a hydrangea.

A. For lilacs: A cutting can be taken from the shrub. Cut off a small, pencil-sized, branch and place it into rooting hormone than plant it into a pot of gravel that is kept moist. Once roots have formed, the plant can be transplanted into the ground. They can also be propagated through a process called layering which is where you bend a flexible branch down to the ground and plant it to allow roots to form on the branch while it is still attached to the main plant. Once roots form, cut it from the parent plant and transplant it. There is more information on this in the NebGuide: Lilacs

Hydrangeas can also be layered to produce new plants or they can be divided. It is too late to do the division this year, but early next spring you can dig up the plant and use a spade to divide the main plant and replant the pieces. Depending on the side you can get 2-4 pieces from a divided plant.

7. Is cedar-apple rust damaging to cedar trees?

A. Cedar-apple rust shows up in the spring on cedar trees as a orange, slimy, ball with horns. This is the gall that opens up with rains in the spring. Cedar-apple rust is not harmful to the cedar tree, it just uses the cedar trees as an alternate host through the winter. When these galls are seen on the cedar, that is the time to spray any susceptible apple, crabapple, pear, or hawthorne tree to avoid damage to them. For more information view this NebGuide

8. This caller has a pink peony that hasn’t bloomed well this year. There is some discoloration and fuzzy appearance to the leaves and buds. What would cause that?

A. This sounds like botrytis blight, a common fungal disease to our peonies. It is not very harmful to the plant itself, so it is not necessary to control it. In the fall, make sure you remove and destroy all of the plant material to reduce the spread to your plants next spring.

9. A caller has a Chanticleer Pear with leaves that have black spots on them and the top isn’t leafing out this spring. What would cause that?

A. This could be due to frost damage as well. Or check the tree for oozing sap along the trunk or branches. The damage could be from borers. It might also be from fireblight which would cause the leaves to turn black on some branches where the end of the branch hooks over like a shepherds crook. Fireblight is likely since this showed up in the tree last summer. If it is fireblight, prune out the infected branches and dip your pruners into a bleach water solution in between the cuts.

10. This caller has roses that had dieback from the winter. She pruned them off in early April and now it looks like the only live growth is coming from the ground. What is wrong with her roses and will they come out of it?

A. Unfortunately, these roses seem to have more dieback from the late frost we saw in April. If there is no green growth showing up on the main part of the plant, it is likely that it has died back. The roots would be shooting the new growth from the ground, but that is not going to be the same type of rose that you had there before because our roses are often grafted. The growth from the ground would be from the rootstock so it wouldn’t be the size and color of rose that was originally purchased. Unfortunately there is nothing that can be done about that. It might be time to go and choose some new rose colors for your garden.

11. A caller has a river birch tree that dropped its leaves in the summer last year. The leaves now are yellow and only the top half of the tree has leafed out this spring. They are 20 year old river birch trees. What would be causing this problem?

A. Look on the branches of the tree for signs of bronze birch borer. Some of the signs of this borer would be rippling on the branches or holes in the stem or branches. If you find the signs of bronze birch borer, you can treat it now with a borer spray or with a systemic insecticide.

12. A caller has a river birch tree that was growing in a clump and one of the trunks of the group died out. Should it be removed now?

A. Yes, any dead part of a tree should be removed as soon as it is noticed. A large part of a river birch, like this, could be hazardous if left standing after it dies. Unfortunately, when that branch is pruned off decay will likely begin but there is no way to prevent that at this point. This will likely be a large portion of the tree removed and that large of a pruning cut may not ever heal over entirely. When a branch doesn’t seal up, decay can get into the tree causing more damage. We don’t advise painting the stump with anything.

13. A question came in via email regarding a red twig dogwood. This dogwood is 4-5 years old and has never been pruned. Following the storms this week, some branches are falling over blocking a mowing path. Can those be pruned now? What should be done with it in the future?

A. Broken branches can be removed at any time. If these are just bending over, they could still be removed if necessary, but they may pop back up to their normal standing position. For future, red twig dogwoods should be pruned to the ground every 3-5 years to maintain that good red color on the twigs. They should be pruned in the late winter to early spring.

14. A lady called who has a Cranberry Bush Viburnum that has dead branches in it. Can those dead branches be pruned out now?

A. Yes, dead branches should always be removed when they are noticed. Check to ensure that these branches didn’t die due to Viburnum borers, if so, treat with a borer spray or systemic insecticide.

15. The last caller of the day has 2 different plants that have problems. A maple tree has brown specks on the leaves and they are falling off the tree. A Peony bush has leaves that are turning yellow along the edges of the leaf. What would be causing these two problems?

A. These both sound like frost damage. They will both be fine. The maple may drop all the damaged leaves and put on new growth.

Yard and Garden: June 24, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for June 24, 2016. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 5, 2016. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Jim Kalisch, Insect Diagnostician for UNL Extension

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

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

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

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

blossom end rot zucchini

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

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

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

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

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

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

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

 

Stable Flies on Dog JAK140[1]

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

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

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

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

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

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

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

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

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

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

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

Yard and Garden: June 10, 2016

Yard & Garden for blogThis is the Q&A for the Yard and Garden show for June 10, 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: Paul Hay, Gage County Extension

1. The first caller of the day has a small Dwarf Alberta Spruce that is turning brown. What would cause this?

A. This would be from spider mites. This particular tree species is very susceptible to spider mites. They can be controlled with a strong spray of water or insecticidal soaps, horticultural oils, or a general insecticide such as a permethrin product.

2. This caller wanted to know if it was still ok to apply the second fertilizer application for the lawn?

A. Yes, you can do one around Memorial Day. I would suggest waiting until after this heat wave passes through and make sure the lawn is well-watered when you do fertilize, so you don’t fertilize to a drought-stressed plant which can cause leaf burn.

3. What would cause Clematis leaves to turn yellow, the plants still bloomed fine this year?

A. Clematis has a problem with Iron chlorosis. This could be iron chlorosis which can be treated with an iron fertilizer.

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Squash bugs on zucchini

4. A caller wanted to know what the best control for squash bugs in the garden would be?

A. Squash bugs will become active soon. Look on the underside of the leaves of your cucurbit plants such as cucumber, zucchini, squash, pumpkins, and melons. Squash bugs lay their eggs on the underside of the leaves. If you find the eggs, squash the eggs or remove the leaves. You can also spray for them. Spray on a rotation of every 10-14 days throughout the growing season. Switch between at least 2 of the following: sevin, eight, or bifenthrin.

5. This caller has rocks near the lawn and near some trees. There are weeds growing up through the rocks. Can glyphosate, or Roundup, be used around these trees?

A. If the trees are not close enough to be spraying directly on the trunk or leaves, then it will be fine. Glyphosate is not mobile through the soil like some chemicals.

6. This caller wanted to know what to do about the gnats outside? He cannot go outside right now without being attacked by gnats.

A. There is no longterm cure for gnats, much like mosquitoes. Using bug sprays, especially those containing DEET, will help the most. If you have an outdoor event coming up, you can treat the lawn and surrounding plants with sevin or other general insecticide, but these will not last for more than 2-3 days.

7. Is it too late to plant sweet potatoes? What can you do about grasshoppers in the landscape?

A. No, it is not too late to plant sweet potatoes. This is a warm season crop that really doesn’t like the early spring planting. They will do fine if planted in late May to early June. For grasshoppers in the landscape, they can be sprayed with any general insecticide. If in or nearby the vegetable garden use sevin, eight, or bifenthrin for safety of the produce. Be sure to spray the insecticides in the ditch, roadside, and fence rows where grasshoppers are found in high numbers.

8.  This caller has hemlock in the pasture. Is it poisonous? How can he control it so his cattle don’t eat it?

A. Yes, poison hemlock is poisonous if eaten, not if it is touched. Cattle can be poisoned by it, but they typically don’t eat the poison hemlock if there is an alternate food source. Use 2,4-D or Grazon in the pasture to control poison hemlock or dig it out.

*Don’t use 2,4-D this late in the season around landscape plants and never use Grazon or other products that contain Tordon in a landscape setting.

9. A caller has common mullein in his pasture. How can it be controlled?

A. Common mullein is best controlled with 2,4-D or Grazon. Make sure you spray down into the heart of the plant to get the chemical past the hairy leaves. It is best to spray the smaller plants, it would be too late to spray the larger plants that already have a flower stalk on them. Removal of the flower stalks will help reduce seed production from the full grown plants.

10. This caller has a 16 foot river birch that was planted last fall. Now the leaves have turned yellow and are beginning to fall off of the tree. Can it get too much water? What would cause this problem? She hasn’t been watering the tree much yet since it was planted in the fall.

A. Yes, plants can be overwatered to cause death. Newly planted trees need to be watered because they have no root system developed. A tree that was transplanted at this large of a size is going to have a great deal of transplant shock to overcome. Water was sitting in the hole when the tree was planted, so there may be an issue with water draining from the location. Use a probe or long screwdriver to see if the tree needs water. Push the probe into the soil 12-18 inches, if it goes in easy it doesn’t need water, if it is hard to push the probe in very far, the tree needs to be watered.

11. The final caller of the day wanted to install an electronic timer for watering his garden. What would be the best time to set his timer to water his garden?

A. 4 am-10 am is the best time to water any plants. This helps to water the plants while they are already wet from the dew period. It also helps to water early in the day so that the plants will dry out before night. Plants that are wet and cooler overnight introduce a great environment for diseases to occur. To reduce diseases, it is best to water early in the morning.

Trees!!

Arbor Day Blog Post 3

Trees are a wonderful addition to any landscape and have a great deal of benefits. I love trees, all trees! As an ISA Certified Arborist, I have a passion for planting trees and keeping our existing trees healthy. With Arbor Day coming up, it is a great time to begin planting trees.

2016-04-02 10.11.52Trees are vital to our lives. They provide us with oxygen to breathe, they increase the value of our homes, and they make us happy and healthy. There are many great trees to choose from that will do well in Nebraska. If possible, a native tree will do much better in our growing conditions because they are adapted to the weather conditions common in Nebraska. At the very least, the tree you choose must be suited to live in your hardiness zone, Southeast Nebraska is in zone 5b.

Good tree choices include:

2014-06-12 16.10.39

  • White pine
  • Norway spruce
  • Colorado Blue spruce
  • Black Hills Spruce
  • Ponderosa Pine
  • Jack Pine
  • Eastern Red Cedar
  • Concolor Fir
  • Douglas Fir
  • Baldcypress
  • Catalpa
  • Gingko
  • Cottonwood
  • River birch
  • Sycamore
  • Linden
  • Kentucky Coffeetree
  • Elm Hybrids
  • Maples
  • Oaks
  • Tree Lilac
  • Hackberry
  • Black walnut
  • Shagbark Hickory
  • Pecan
  • Chestnut
  • Sweetgum
  • Chanticleer or Cleveland Select Pear (not Bradford)
  • Serviceberry
  • Honeylocust (thornless)
  • Redbud
  • Black Locust
  • Pawpaw
  • Horsechestnut

When looking for trees for your landscape, remember to utilize diversity. Increasing species diversity prevents us from “putting all our eggs in one basket” and prohibits any single insect or disease from destroying a community’s entire forest resource. Pine wilt, Dutch elm disease and the approaching emerald ash borer (EAB) all reinforce the importance of species diversity. In fact, forestry experts recommend that no single species make up more than 10 percent of the entire community forest resource. This comes from the ReTree Nebraska page. ReTree Nebraska is an affiliate of the University of Nebraska-Lincoln that focuses on “raising public awareness of the value of trees and reverse the decline and improve the sustainability of community trees and forests”. ReTree has been working on a list of great trees for Nebraska, each year adding more trees to that list. In 2016, they added American Linden to that list.

For care of any tree, water is a vital element to health and growth. Always water newly planted trees, shrubs, or any other plant immediately after planting. Trees should be watered every 10-14 days throughout the growing season and even some during the winter on warmer days. Each watering should give the tree 1-2 inches of water. The best way to determine if a tree needs to be watered is to insert a soil probe or 12-inch-long screwdriver into the ground around the tree. If it goes in easily there is no need to water, if it is difficult at any point then water is necessary for the tree.

tree mulchA mulch ring should be established and maintained around every tree. Mulch helps to keep the roots cool in the summer and regulated to a uniform temperature through the winter rather than the temperature fluctuations we often see during the winter months. Mulch will also help keep weeds down and reduce competition from those weeds for water and nutrients. Mulch also reduces damage to the trunk of trees from lawn mowers and trimmers. Finally, mulch is a way to hold moisture for use later by the tree. Mulch rings should be only 2-3 inches deep and in a circle around the tree at least 2-3 feet out. Organic mulches are a better choice than inorganic mulches. This mulch will need to be renewed every 1-2 years to maintain an effective layer because it will break down and improve the soil over the growing season.

 

Landscape Winter Watering

Magnolia Tree in Winter 2With October over now, we look toward November and December and the snowy, cold, icy weather that comes with it.  Most people believe that once winter weather begins, our plants no longer need any watering.  However, if we are not receiving much natural precipitation and the weather is warm enough to thaw the ground during the day, we do need to supplement water to our plants.

If we consistently have snow cover on our lawns throughout the winter, there is no need to worry about watering our plants.  However, if we don’t see much snow throughout the winter, we need to water our plants.  Some of the plants that are most affected by winter desiccation include maples, lindens, dogwoods, willows, and paper birches.  It is most important to water newly planted trees and shrubs throughout the winter, versus watering all of your older, more established plants.  However, if it is a very dry winter, all of your trees and shrubs would benefit from a watering at least once a month throughout the late fall and winter months.

Tips for Watering in the Winter Months:

  • Water only when the temperatures reach 40 degrees Fahrenheit or above
  • Water during the middle of the day to allow all of the water to soak in prior to freezing at night
  • Water with a hose or a watering can or bucket, do not use your irrigation system in the winter or you will have to drain the pipes again and you have more of a chance to break the pipes due to freezing.

We also need to do other things to protect our plants during the winter.  We need to make sure we cover around the base of our trees and shrubs with a layer of mulch.  This layer should only be 3 inches deep, any deeper than that and you can acquire problems with mice and voles getting into that layer and causing damage to your trees and shrubs.  Remember that plants with a hollow stem should not be pruned back until the early spring rather than in the fall.  This includes butterfly bush and many of our roses.  If these are pruned back in the fall, they could get moisture into those hollow stems and freeze and thaw throughout the winter which could crack the crown and kill the plant.

tree wrappingYou may also want to wrap the trunk of young, thin barked trees.  Sunscald is a problem that occurs when the tree gets too warm on the south and west sides of the trunk in the winter.  The cells on the sunny side of the trunk warm up and begin to become active in the winter and then freeze in the evening.  This problem can cause a canker to develop on the trunk of the tree.  Sunscald can easily be prevented by wrapping those thin barked, young trees during the winter with the white tree wrap to keep it cooler and shaded on those warmer, sunny days in the winter.

Photo by Sarah Browning, Lancaster County Extension