Tips for Fall Plant Protections

Protect plants for winter, blog

Fall has officially arrived. There have already been frost advisories for the western part of the state, so it won’t be long until frosts occur here. It is at this time that you need to think about care for your plants to protect them through the winter. Here is a ‘To Do’ list to prepare your lawn and garden for winter.

Care of newly planted trees should be considered. If it is a thin barked tree, add a tree wrap to protect it from sunscald. Sunscald is a condition that occurs during the winter with the rapid cool down at night of the cells in the trunk of the tree. The warm up can occur in the winter on warmer days but when night comes, those cells freeze and burst, causing damage to the trunk. Tree wraps will help protect young trees from this condition, but only leave the wrap on during the winter months and allow the trunk to be opened up during the summer to avoid damage from insects and disease.

tree wrapping
Tree Wrap

Young trees would also benefit from a fence around the tree to protect it from damage from rabbits and voles during the winter months. During the winter, these critters chew on the bark of our trees which causes wounds and, in some cases, girdles the tree leading to eventual death. A 2-foot high fence of chicken wire will be sufficient to protect your tree from both of these animals. Make sure the fence is dug into the ground a couple of inches so the voles can’t get under it.

Winter mulch can be applied when temperatures are consistently dropping down to the twenties each night. Winter mulch is the heavier layer of mulch we apply to plants like chrysanthemums and strawberries to keep them from having temperature fluxes in the soil they are planted in. Any plant that may be prone to frost heaving, the plant being pushed up out of the soil by a constant freeze and thaw condition. Plants that were just planted this fall could also benefit from winter mulching. This mulch can be up to twelve inches deep, which is much deeper than we usually advise but is needed for winter protection. It is better to use coarse wood chips, straw, or leaves for winter mulch rather than grass. Be sure to level the mulch back down to 2-3 inches in the spring.

Clean up all spent leaves of annual and perennial plants. Remove the dead plant material and compost it or dispose of it. If there was a problem with a disease or insect problem in the plant this summer, it would be best to dispose of it to reduce the problem with that insect or disease next year. Be sure to wait until the plants have turned brown in the fall before removing this plant material to allow them all the time available to build and store up sugars for next spring.

Now is the time to dig up your summer bulbs to prepare them for winter storage. Plants such as gladiolus, cannas, begonias, caladium, elephant ear and dahlia need to be dug up in the fall and stored indoors over the winter. They need to be dug up prior to a hard frost, or shortly after the first frost. Once the bulbs are removed from the ground, they need to be cleaned off, removing the leaves as you clean, and cure or dry them for 2-3 weeks. Then place the bulbs in crates or boxes, allowing for air flow. Store them throughout the winter in a cool, dark location such as a basement. Check the bulbs periodically through the winter to ensure no bulbs are starting to rot or mold.  If any do start to rot or mold, discard them immediately.

Yard and Garden: July 8, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for July 8, 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: Dr. Paul Read, Viticulture Specialist for Nebraska Extension with Guest Intern Vivian from China

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/9b24 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 they can prune the Cleveland Pear tree that has branches that are low and too tight to the trunk?

A. The best time for pruning a tree like this would be while it is dormant. For a situation like this where the caller is only removing a few branches to help with the growth of the branches and to reduce future problems with the tight branch arrangement it would be fine to remove them now. It would be better to remove branches like this before they break in a storm due to weak attachment to the trunk.

2. A caller has Anjou pear trees that were planted in 2013. Now the bark from the graft union up about 10-12 inches has the bark peeling and now has some black leaves. What would cause this?

A. This would be from sunscald. There is no way to fix sunscald once it occurs. Don’t paint the wound with anything, allow it to heal itself. The black leaves could be due to fireblight. You can cut 6-8 inches past the diseased portion of the limb to cut the fireblight off the tree. The black could also be anthracnose which is not damaging to the plant and there is no need to spray anything for anthracnose.

sunscald-bugwood
Sunscald Photo by William Jacobi, Colorado State University, Bugwood.org

3. This caller has an oak tree that is dripping sap on the vehicles parked under it. What would cause this?

A. Aphids feeding on the leaves of trees will excrete honeydew that can drip on vehicles underneath the tree. Aphids are not very damaging and have a lot of predatory insects that feed on them. They can be sprayed with sevin or eight or another general insecticide, but they should fade out on their own with predator insects.

4. A caller has blue spruce trees that look dirty but the tips are still green. What would cause this?

A. This is most likely due to environmental stress from the heat and humidity. If the ends of the branches are still green, the tree will be fine. Make sure your tree has a mulch ring around it and that you keep it well watered in the heat of the summer.

5. This caller has a patch of lilies where a quarter of the patch has only grown to be about 6 inches tall for the past 2 years. The rest of the patch looks good, but this area doesn’t look healthy. Can these be improved?

A. This could be due to hardiness in some varieties that are only suitable for our environment for a couple of years. It also could be due to some bulb mites. It would be a good idea to dig up some of the bulbs to see if they have any damage on the bulbs.

6. A caller has a pine tree with a lot of sap on the branches and the grass in the lawn won’t green up. Why is this?

A. Woodpeckers or insects feeding on a pine tree can cause sap to leak from the wounds left behind. The insects can be controlled with bifenthrin or permethrin (eight). If it is woodpeckers, the damage is minimal and will not cause any problems to the tree. Check how much water the lawn is actually receiving by using catch cans during the water intervals normally followed. Lawns need 1 1/2 inches of water per week. If the water is fine, there are a lot of fungal diseases in the lawn, it could be one of those. Fungal diseases in the home lawn are usually sporadic and therefore don’t require fungicide applications.

7. This caller lives on an acreage surrounded by farmground. She is considering growing grapes on this large plot of land. Are grapes easy to grow and would grapes have a benefit to the wildlife in the area?

A. Grapes are a large commitment, especially if you plan to sell products from them. You can be successful with only a few plants for the family to use for grape production. A few good choices for this area would include Frotenac or Valiant. The first year the grapes would need extra care, but after that they would be more self-sustaining. Deer will feed on the foliage. If you decide to grow your grapes for commercial use, register  your acreage with the driftwatch website at  www.fieldwatch.com to help avoid problems from drift since grapes are very sensitive to drift damage.

8. A caller has strawberries that were planted and now have very small fruits and the plants are not making runners.

A. Everbearing strawberries are typically very small for fruit size. You might try planting some newer varieties that are June bearing to get larger fruits. Some good choices would include honeoye or albion or sparkle.

9. This caller has an ash tree that is 7 years old and the tree snapped off in the wind. There is mold in the trunk and it is suckering. What can be done to plant a new tree?

A. You can get a company to come in and grind out the stump or rent a stump grinder to do it yourself. The suckers that keep growing back will continue to for a few years, they can be cut out and treated with a roundup or 2,4-D product. You can plant a new tree within just a few feet of the old tree, since this wasn’t a very large tree yet.

10. A facebook photo came in with a odd structure that appeared by a tree. What is this?

A. This would be a stinkhorn fungus. They are not harmful to the plants growing in the area. There is not control other than mechanical removal of the fungus. Do not eat these as they are not edible, they would be a poisonous mushroom.

DSCN6327
Stinkhorn Fungus

11. The last caller of the day has tomatoes in a raised bed. When they ripen for harvest, the end of the tomato seems blighted. What would cause this?

A. This is blossom end rot. It is a calcium deficiency that develops in our plants in drought situations because calcium is only available to plants after it has been dissolved in water. There is no control for this, it should only last for a few weeks early in the growing season and then the plants should grow out of it.

Yard and Garden: May 6, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for May 6, 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: Jennifer Morris, Forest Health Specialist for the Nebraska Forest Service

1. The first caller of the day has peach, plum, and apple trees that were recently planted. Should she use tree spikes for fertilizer for the trees and when should that be done?

A. Fertilizer for a tree is usually not necessary in Nebraska soils. Let nature take its course to naturally fertilize the tree. Fertilizer should only be used on trees, or any plant, as it is necessary. A plant can be damaged or even killed if they have too much of a particular nutrient, so it is best to do a soil test prior to applying any type of fertilizer to your plant.

2. A caller has grasshoppers in his lawn and has problems with large populations in the past, but he also has beehives nearby where he would want to spray to control the grasshoppers. Can he treat the grasshoppers and not harm the bees?

A. Insecticides that are commonly used as sprays for grasshopper control are very toxic to bees. You should only use insecticides for the grasshoppers in this situation for serious situations where chemical control is necessary. If sprays are warranted, you would want to do so on a calm day so the spray does not drift to the bees and mow the lawn first to reduce flower heads present that could get pesticides on them to get onto the foraging bees.

3. There is a caller who wants to plant some new apple trees. The trees he currently has continue to face problems with cedar-apple rust. What tree cultivars should he choose that will not have the problems with this disease?

A. There are many apple trees that are resistant to cedar-apple rust. When planting a new apple tree it is best to go in with a tree that is resistant to this disease because cedar trees are common in Nebraska, which is the alternate host. This allows most any apple or crabapple tree to be vulnerable to the disease. For resistant cultivars, see page 3 of this NebGuide on Cedar-apple rust by Amy Timmerman.

4. A caller wanted to know if they can use Roundup (or other glyphosate product) in their garden to kill pampas grass? Can it be wiped onto the stalks of the plant and not harm the peonies or raspberries that are growing with the pampas grass?

A. Yes, it can be used among raspberries and peonies, but it needs to be carefully applied so that you don’t get it on the leaves or other plant parts of the desirable plants. Painting the glyphosate product onto the leaves of the pampas grass will work into killing the grass and will keep it from getting onto the desirable plants. Grass-b-gone may work for it in the peonies and can be sprayed directly over the peonies and cause no harm to them, however this product should not be used in crops that are used for food or feed.

5. A caller has a mum growing on the east side of their house and it didn’t come back. Why is that?

A. Some of our mums are not as hardy as others. This may have been one of the lesser hardy mum plants. This mum was also moved in the fall so it may not have been ready for the winter after being moved or it could be planted in a more exposed location. If there is no green showing in the plant at this point, I would assume it is dead and it is time to replant.

6. A walk-in clientele asked what the orange pods were on her cedar tree? She also wanted to know if she should remove the cedar tree or if she can treat it?

A. This is the gall of the cedar-apple rust disease. In the rainy portion of the spring these show up to release the spores of the disease to move to apple trees. This disease is not harmful to the cedar tree so no treatment and definitely no removal of the tree is necessary.

7. A caller wanted to know how to start a new plant from the family tree peony plant.

A. Prune off a branch of the peony and place it into rooting hormone and then into soil or into a pot of gravel that is kept moist to start roots. Once roots have begun, the plant can be planted into the ground.

8. This caller has a 12-15 year old apple tree that has bark on the trunk that is splitting on the southwest side of the trunk. What would cause this and is it harmful to the tree? He also has a tree that has holes in the trunk that are in a row and about the size of a pencil. What is this from?

A. The holes in a line on the trunk of a tree would be from a yellow-bellied sapsucker, a type of woodpecker. This is not harmful to the tree and has no management strategy. As for the bark splitting on the apple tree, this sounds like sunscald. This is a disease that occurs in the winter when the cells in the bark freeze and thaw quickly and bursts the cells causing the split. There is no control for this and the trees will typically live a long, happy life after this occurs but the scar will remain for the life of the tree.

9. The final caller of the day has a windbreak with evergreens that were planted 9 years ago and they are too close together. What is the recommended spacing for trees in a windbreak?

A. 14-16 feet between trees is the average spacing requirement at this point. You need to maintain that distance so that when the trees are full sized they don’t overlap each other too much which can cause more disease problems.

 

Winter Tree Problems

2015-02-04 09.33.35During the winter months we tend to not worry much about our plants, but a great deal of damage can occur to them during the winter. A couple of the problems we often see in the winter would be sunscald and winter desiccation. Many of these problems may not even be noticed until the spring months and we can help prevent some of them during the fall.

Sunscald is a common problem on young trees and thin barked trees such as maples. We may notice discolored bark, cracks, or sunken areas, in the trunk of the tree and bark falling off of those trees. It is commonly found on the south and west sides of the tree and is therefore also referred to as southwest disease.

Photo by William Jacobi, Colorado State University, Bugwood.org
Photo by William Jacobi, Colorado State University, Bugwood.org

There is no cure for the tree once it develops sunscald, but many trees will heal this damaged area. Because this is an opening in the tree, other problems with insects and diseases can affect the tree. Sunscald is a problem that is easily prevented by using a tree wrap around young and thin barked trees from late fall through early spring. Also, many of our trees that are affected by sunscald are drought stressed, so maintain adequate moisture to your trees throughout the year and ensure that they go into the winter well watered to help prevent sunscald.

Winter desiccation commonly occurs on evergreen types of trees and shrubs. All trees are still transpiring, or losing water, throughout the winter months, evergreen trees are transpiring at a higher rate than deciduous trees. Winter desiccation occurs when the amount of water lost is greater than the amount of water the evergreen takes in throughout the winter months. The branches and needles of our trees will die. The damage from winter desiccation is brown needles out on the ends of branches. However, the damage from winter desiccation will not usually show up in our trees until early spring, so they will stay green through the winter.

2014-04-23 10.45.50

The management for winter desiccation is to ensure adequate watering throughout the entire growing season. Make sure that the tree is well watered going into the fall. Also, water throughout the winter when the ground is not frozen to help the trees through a dry winter, if necessary. Winter watering should occur during the day on days when the temperature is 40 degrees Fahrenheit or above and is only necessary 1-2 times per month until spring. You can prune the dead branches and brown needles off of the tree, but wait until after new growth has begun, so you can see which parts of the branches are dead.