Peach Leaf Curl

Lately, I have had quite a few community members come into the office with a problem on their peach tree. The leaves look funny and have a pinkish color to them. The same problem is being seen throughout the area and unfortunately, there is nothing we can do about it, at least not for this year. The problem many people are dealing with is Peach Leaf Curl.

Peach leaf curl is caused by the fungus Taphrina deformans. This fungal disease is one of the most common diseases in the home orchard and can affect the blossoms, fruit, leaves, and shoots of peaches and nectarines. (Cherries have a similar leaf curl diseases caused by T. cerasi.) Peach leaf curl is more severe following cool, wet springs; temperatures between 50 and 70 degrees F are ideal for infection, which is why we are seeing it so often this year.

Peach Leaf Curl, Paul Bachi, Univ of Kentucky R and E Center, Bugwood

Photo of Peach Leaf Curl is from Paul Bachi, University of Kentucky Research and Education Center, Bugwood.org

The primary symptom is a thickened, puckered area on leaves which will turn yellow to red or purple with the loss of chlorophyll. These leaves may prematurely drop, weakening the tree and making it more susceptible to other diseases, pests, and cold injury. The disease can also result in reduced fruit set, size, and quality.

A single fungicide spray applied while trees are still dormant (just prior to bud swell), thoroughly covering all branches, shoots, and buds will control peach leaf curl. Effective controls include Bravo, Ziram, and copper compounds.

At this time of year, most infection has already occurred, and fungicide sprays are relatively ineffective. Fruit on defoliated trees should be thinned to reduce stress and improve tree survival.

This information on Peach Leaf Curl came from Connie Fisk, a fruit tree expert for Nebraska Extension located in Cass County. Read more from Connie on her blog, Food Adventures with Connie

Another thing to think about this time of year, is what type of fruit tree to plant if you are thinking about planting new trees. You need to decide what type of fruit you prefer to grow, what you will be using your fruit for, and if the tree is self-fruitful or if you need to plant a pollinator tree nearby. It is also best to plant fruit trees that are resistant to the common diseases found in our fruit trees. For apple trees, select a tree that is resistant to cedar-apple rust and apple scab. For peach trees, choose a tree that is resistant to bacterial spot. For pear trees, choose one that is resistant to Fire Blight.

apples-A. Henneman flickr

Flickr image courtesy of Alice Henneman per CC license

For Apple trees, some good choices include Redfree, Johnafree, or Liberty. For Pear varieties, look at Moonglow, Luscious, Lincoln, Magness, or Seckel. For Peaches, choose Reliance, Red Haven, Contender, or Madison.

There are many other great choices for fruit tree varieties to use. Nebraska Extension released a NebGuide in July of 2016 called ‘Fruit Tree Cultivars for Nebraska’. It is a good guide that helps you to find the fruit tree variety or varieties you need for your fruiting wishes.

Do prune this…Don’t prune that

2013-05-09 10.12.37

Spring will be here before we know it. With all the warm weather lately, it is hard to remember that spring has not already sprung in Southeast Nebraska. But, with the warmer weather, there are a few things we can do in our landscapes and a few things we should avoid.

Don’t prune spring blooming shrubs this time of the year. Plants such as lilac, forsythia, spring blooming spirea, and some hydrangeas produce flowers in the fall of the previous year to bloom early in the spring. If you prune these plants now, you will cut of the flower buds and not have those flowers to enjoy this spring. So avoid pruning those shrubs in the spring. Spring blooming shrubs should be pruned immediately after they finish blooming in the spring. This will allow for the best growth of the plant and for best flowering each year.

Forsythia-Richard Elzey, Flickr

Forsythia Flickr image courtesy of Richard Elzey per CC license

Prune trees this time of the year. February and March are the best months of the year to prune deciduous and fruit trees. It is best to prune these trees during the winter months because it doesn’t affect fruiting that occurs in the spring and it allows the tree to seal up the wound quickly in the spring when growth resumes. It is also easier to see areas that need to be pruned in the winter months. You can see where branches are crossing or rubbing and where the branches are too dense. In addition, pruning in the late winter helps reduce the transmission of different diseases that aren’t active. However, it is best to avoid pruning maple, willow, poplar, birch, hackberry, Kentucky coffeetree, black walnut, honeylocust, and elm due to the high sap flow they have in the spring. Freshly cut wounds this time of year will cause the tree to “bleed” or have excessive sap flow out of the wounds. They are best pruned in the late summer to early fall to avoid sap flow.

Don’t uncover perennials yet. It is still winter, for a few more weeks. Many of our perennials are getting confused with the weather lately and some are starting to green up already. Tulips, Iris, and peonies are starting to emerge and crocus are blooming already. However, if you pull the winter mulch back from these plants or remove the plant material that was left on the plants through the winter, you will be exposing the plant to cold temperatures and removing its protection. The plant will have better survival and less winterkill if you leave them covered through the winter months.

Plan your gardens for the spring. Late winter is a great time to plan what you will plant in your vegetable gardens so you can format your plan to know what you have space for and to ensure that you move your crops around from year to year. This will also help you decide what seeds to start indoors. Mid-February through March is a good time to start the seeds of your chosen warm season crops indoors. Make sure that you have them in a warm location with 14-16 hours of light on them everyday.

crabgrass, Joseph Berger, Bugwood

Crabgrass photo is courtesy of Joseph Berger, Bugwood.org

Don’t use pre-emergent herbicides for crabgrass yet. The soil temperatures have been at an average of 40-45 degrees Fahrenheit over the past 7 days. Even as warm as it has been, crabgrass has not yet begun to germinate. If the temperatures continue at this pace, it will probably germinate early, but we still have a couple of weeks before we need to get the pre-emergent herbicides on. Remember, crabgrass germinates at 55-60 degree soil temperatures, so we still have a bit of warming up to do.

Yard and Garden: June 17, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for June 17, 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: Connie Fisk, Cass County Extension

1. The first caller of the day transplanted pear and maple trees in December. Recently, these trees turned brown and lost their leaves. What would cause this?

A. This year the weather has been ever-changing. The drastic change from wet and rainy to hot and dry has been hard on many of our plants. It sounds like these plants need watered. Water on a slow trickle about one time per week for 45 minutes-1 hour and make sure the trees have a mulch ring that is at least 2-3 feet out from the base of the tree and only about 2-3 inches deep.

2. This caller has a locust tree that he topped and wanted to use the removed branches to make a trellis for his vegetable garden. Now, the branches are sitting in a pile and sawdust has developed around them. What is this and is it concerning for his vegetable garden?

A. This would be either carpenter ants working on the decaying material of the branches or it could be another type of insect that is emerging from the branch that was developing in the branch over the winter months. This will not cause any problems to your vegetable garden.

*Note: It is not recommended to top a tree due to the weak, unproductive branches that will emerge from the tree.

3. A caller has scotch moss that she purchased for her fairy garden. She purchased it one month ago and has not had time to plant it into the fairy garden. Now, part of it has turned brown in the center of the plant. What can she do to fix this?

A. It should be planted into a garden or the fairy garden as soon as possible to ensure it gets room to grow. Also, this could be due to watering issues. She can prune out the dead growth and the rest should be fine if it gets planted.

4. This caller has 2 Northstar dwarf cherry trees that were planted this spring. One is fine but the other has not leaved out this spring. Will it survive?

A. No, it will probably not live at this point. It won’t hurt anything to leave it in for this growing season to see if it comes out of it, but it is late in the season for no growth to be on the tree. Water it early in the morning to try to help it come out of possible late dormancy.

5. A caller has apple trees that were planted last year. They are 6-7 feet tall. One tree is beginning to bend over from the top, the leaves are green with some yellow leaves throughout. What would cause this?

A. This could be due to fireblight. This is a bacterial diseases that can cause dead leaves and the end of the infected branches will bend over like a shepherds hook. Prune out the infected area by cutting back into the healthy area 8-12 inches past where the scorched area appears. Clean pruners in a bleach water solution between each cut to reduce the risk of spreading the disease. Do not compost infected branches.

6. A caller has a 30 foot tall blue spruce that they would like to trim off some of the bottom branches. Is this an ok practice?

A. Yes, that can be done. The branches removed will not regrow and underneath the weeds and grasses will need to be controlled. It would be best to then use mulch and/or a groundcover under the tree to help with weeds and mowing around it.

7. This caller has a peach tree that split down the middle of the trunk. Can it be saved?

A. No, any assistance will be just to help the tree limp along until death. It would be best to replace the tree at this point. Once the tree splits it is then open to disease and insect issues with no way to remedy it for long-term management.

8. A caller has maple trees that are 5 years old and now the trunks look like the bark is peeling off and you can see the inside. This damage is on the South and West sides of the tree. What is it from?

A. This would be sunscald, also called southwest disease because the damage occurs on the south and west sides of the tree. Sunscald occurs in thin barked trees during the winter when the cells of the tree rapidly freeze and thaw on warm winter days. Now that the damage has occurred there is no control for it. For new, thin barked trees, they should be wrapped during the winter months for the first few years of their lives. The damage is minimal and won’t kill the tree.

9. This caller has hollyhocks that the lower leaves are drying up and falling off of the plant. What would cause that? Also, there are mums blooming now. Can she cut them back?

A. This sounds like a fungal leaf disease due to the wet spring. Remove the leaves and destroy them. Mums can be pinched back throughout the summer months to keep them at a good size and to help with blooms in the fall. They can be pinched back until the 4th of July.

10. A caller wanted to know what causes blue-green algae in a lake?

A. It is a combination of environment, low water levels, and nutrients found in the lake. For more information visit: http://water.unl.edu/lakes/toxicalgae-faqs

11. This caller lost 2 peach trees and a plum to borers. Is it common? Did the tree have borers when it was purchased? Can others be saved?

A. Borers are common in peach trees. They can be treated. For information on treating these borers, visit the spray guides section on https://food.unl.edu/local-food-production

12. An email question came through with an algae problem in a birdbath. What can be done to control this algae?

A. This birdbath needs to be cleaned more often and scrubbed out to remove algae growing on the bottom of the birdbath. For more information visit: http://lancaster.unl.edu/pest/resources/waterbirds.shtml

13. A caller has a leaf tree that has developed peaches every year except for the past 2 years. What would be causing this?

A. A late frost has occurred the past 2 growing seasons which would cause a decrease if not an entire loss of the peaches that had begun before this frost occurred. There has also been low pollination the past couple of years due to wet spring during the pollination period.

14. This caller has a established silver maples that are suckering. Can this be sprayed with anything to stop the suckers from forming?

A. Unfortunately, no chemicals can be used on suckers because this growth is coming from the roots of the main tree. Chemicals used on the suckers will kill the entire tree. The best defense for suckers is to continually prune them out.

15. A caller has apples that tend to get worms and spots on the fruits. What can be done to help with these problems?

A. For backyard trees it might be best to just tolerate occasional insect and disease pests. If the problems are minimal, it is much less work to just cut out the bad spots for home use. You can use insecticides, just follow the regulations on the spray guides found at: https://food.unl.edu/local-food-production Sanitation is also important, remove and destroy all fruits off the tree and off the ground and leaves around the tree in the fall to destroy overwintering locations for these pests.

puffball

Puffballs are identified by their solid structure throughout the fruiting body, which is typically spherical in shape. (Photo from NebGuide Mushrooms, Fairy Rings, and Other Nuisance Fungi in the Landscape courtesy of R. Mulrooney, University of Delaware)

16. The final caller of the day has a fungus in the lawn that is like a ball on top of the ground that when pushed on releases many spores. What would this be?

A. This would be a puffball. A type of mushroom. There is no control for them, it is best to just remove the puffball structures as you see them and destroy them.

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.

 

Yard and Garden: April 15, 2016

Yard & Garden for blogThis is the Q&A for the Yard and Garden show for April 15, 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: Jeff Culbertson, UNL Landscape Services

1. The first caller of the day has asparagus that she planted last Spring. What needs to be done with the plant now?

A. Light harvest can be done the second growing season and then full harvesting can begin the third season. Mulch it now to keep weeds down, herbicide sprays are not able to be safely used too close to growing asparagus. Cut the plants back in the fall after they have grown well all season. Fertilizer can be applied now or in the fall.

2. How do you control moles in the lawn? How do you control grubs in the lawn?

A. For mole control, see this guide from the Internet Center for Wildlife Damage Management: http://icwdm.org/handbook/mammals/mam_d51.pdf Make sure that you have found an active run area before implementing any traps by stomping the mounds down for a couple of days prior to setting the trap. For grub control, the best option is to apply a product containing Imidacloprid around the third week of June.

3. This caller from the Southern part of the United States said that it is difficult to grow asparagus in the south. Is this due to the lack of dormancy in the south compared to what we have in Nebraska?

A. Yes, asparagus would need to have a rest period that occurs during our winter in Nebraska. However, the roots are also prone to root rot problems, so it might be that your soil could be too high of clay that isn’t allowing the asparagus roots to dry out enough.

4. Another caller has Iris that they have sprayed with Sevin for iris borers that are always a problem. Is this the best product and when should she be applying it? Also, she applied lime to the plants and now they are a lime green color instead of the deep green they are supposed to be. What is causing this discoloration?

A. Lime is used for acidic soils to raise the pH. In Nebraska, most of our soils are heavy clay and therefore already have a high pH. The addition of the lime to the soils in this case is causing chlorosis on these iris plants. It will work through over time, but for a couple of years the iris may look a little tired. The Iris borers have not shown up yet, but a treatment with an imidacloprid, permethrin, or bifenthrin soon or just as the larvae come out would be ideal for control.

5. This caller is wondering what the timing is for fertilizer with crabgrass pre-emergent herbicide? He is also wondering how to control bindweed in bromegrass?

A. Anytime in the next week or 2 would be ideal for fertilizer and crabgrass pre-emergent use this year. The soil temperatures are at 54.9 degrees Fahrenheit for the 7 day average. Crabgrass will germinate at temperatures between 55-60 degrees Fahrenheit, so you can begin applying your control methods anytime now until the end of the month for best control. The bindweed can be controlled with trimec  if used 2-3 times per summer. Keep the bindweed mowed to prevent flowering from occurring to reduce the amount of seed left in the grass.

6. A caller has cedar trees that were recently pruned from the bottom up. What would be a good grass to grow under these trees?

A. A fescue grass would grow well in this shady environment. Also, a nice groundcover such as purple leaf wintercreeper would be a good alternative to grass to reduce mowing under the tree and to grow better in the shade of the tree.

7. This caller from Hickman has a cherry tree. Every year they mow off many “little trees” that grow up and around the cherry tree. Is there anything else to do to reduce the occurrence of these trees?

A. Suckering occurs with many different tree species. These suckers may be growing off of the roots of the main tree so chemicals should not be used or else you may end up killing the desired tree as well. Cutting them off or mowing over them before they grow too large would be the best options for control.

8. This caller has fruit trees. He is wondering if a product called “fruit tree drench” for insects would be ok?

A. Not knowing the active ingredients in this product makes it hard to answer the question. Systemic insecticides are not usually safe for use in plants that are edible because a systemic insecticide will move throughout the entire plant, including into the edible parts. It is suggested to do more research on the safety of the product or to move to a spray type of insecticide that is not systemic to reduce the health hazards that may be a problem with systemic insecticides.

9. Another caller has an apple tree that is 7-8 years old. The last 3 years it has produced nice apples but they are rotten inside. Now there are not many apples that are not rotten on the inside. What can be done for this?

A. Sanitation is going to be key for controlling this disease, known as black rot of apples. A orchard fruit tree spray program can be used to minimize the damage as well. Pruning may need to be done to remove any branches that are dead or diseased.

10. A caller wanted to start a new strawberry patch. How far should the plants be spaced in the garden and what should be done to the soil for improvements?

A. Till in compost and topsoil for increased organic matter and reducing compaction in the soil. Space the plants 1 foot apart.

11. This caller has a maple tree that is not budding out and has not yet lost the leaves from last spring. Will it survive?

A. Some maples, such as the sugar maples, have not yet leafed out for this spring. Use the fingernail test to scratch the bark lightly on smaller branches to see if there is green underneath the bark. Green under the bark means the tree is still alive and waiting to come out of winter dormancy, brown under the bark means it died over the winter.

12. A caller wants to know about the “spray on grass”. Will it work for overseeding?

A. Should work ok, but check with the types of grass seed included in these cans. Many of these mixes have perennial rye which doesn’t last long in Nebraska environments. Also, check for the amount of weed seed found in the mixture.

13. Is it too late to thin Iris plants?

A. The best time to transplant and divide iris plants is in the fall. Use a garden fork to lift them from the ground. Look for borer holes, and then replant them making sure to not plant them too deeply.

14. What is the best advice for improving soils for growing watermelons?

A. Lighter soils are best for growing watermelons. Add compost to improve the fertility.

15. A gentleman has cherry trees, apricot trees, and peach trees. What type of mulch should be applied to help keep the trees watered?

A. Organic mulches should be used, such as the wood chips. They need to be applied at a uniform depth of 2-3 inches in a ring around the trees that is at least 2-3 feet wide around the tree. Water the trees for about 45 minutes every 10-14 days, more may be necessary during the hot, dry periods of the summer. Use a soil probe or long screwdriver to see if the trees need water. Push the probe into the soil up to 12-18 inches deep, if there is resistance any time while pushing into the ground, the trees need water.

grape hyacinth, ricky layson photography, bugwood

Grape Hyacinth photo from Ricky Layson, Ricky Layson Photography, Bugwood.org via Creative Commons License.

16. A caller has grape hyacinth growing in her lawn. What can be done for management?

A. Mow it off. This is a short lived annual plant that is close to the end of its lifetime for this year. There is no need to use chemicals to control this plant.

Yard and Garden: April 17, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for April 17, 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: Dr. Paul Read, Professor of Horticulture, Viticulture Specialist

1. A Caller wanted to know if this was a good time to transplant rhubarb?

A: Now would be a fine time to transplant rhubarb. If you wanted to harvest from it yet this year, it would be best to wait until the fall to transplant it. Rhubarb should not be harvested from within the first 1-2 years after transplanting to allow the plant to build a good root system before harvesting begins. Make sure that rhubarb is planted in a well-drained location to avoid getting crown rot, a disease that will eventually kill the plant.

2. An email listener wanted identification and control strategies on her plant with purple flowers that is blooming now.

A: This is henbit, a winter annual that is flowering to complete its lifecycle. Because henbit is basically done growing for its lifecycle, it is best to leave it alone and let it die naturally in the next few weeks. The seeds are already in the soil for next year. Henbit is best controlled with a 2,4-D product in the fall. Mark the areas where henbit is found in your lawn this year and spray those areas in the fall. Management also can be achieved by overseeding turf into those areas where henbit is found or planting something else to compete with the henbit.

3. This caller wanted to know how to control clover

A: The best time to control clover would be in the fall with a couple of applications of a 2,4-D product. Applications of this product now can be useful, but will not eliminate the problem altogether. Be sure that when you apply 2,4-D to your landscape to not allow it to drift to any other broadleaf plant, including our trees, shrubs, and perennials. Also, only spray when the temperatures are below 80 degrees Fahrenheit.

4. A gentleman has a lawn that has been neglected for a while that he is struggling to keep turf alive in a full-shade location with poor soil. What can he do to get the turf to live there? Also, in another area of full sun, would dwarf fescue be a good turfgrass choice?

A: Because it is poor soil that had subsoil put on top of the existing soil, it would be best to aerate and add organic matter to try to improve the soil conditions. Full shade is difficult to grow turf in, so it would be best to choose a full shade perennial or groundcover or somehow prune the trees to improve the sunlight for the turf. Dwarf fescue is not a good choice because the root systems are not as deep as the turf-type tall fescues or Kentucky bluegrass.

5. What would be the fruit tree spray schedules for cherry and apple trees?

A: Orchard fruit tree sprays can be applied to both of these types of trees on a 10-14 day interval, while avoiding the blooming period to avoid damage to the pollinators. There are guides to spray schedules from many Universities including one for homeowners from Missouri Extension

6. A caller wanted to know what are some good varieties for pear trees in Nebraska? Does he need multiple species for pollination? How does he mulch these trees?

A: Pear trees are not self-pollinated so you will need to plant 2 different varieties to get fruit. Some good choices for Nebraska would include Luscious, Harrow Delight, Harvest Queen, and Seckel. A mulch ring is necessary to help the tree survive, it should be only 2-3 inches deep.

7. This caller used crabgrass preventer with fertilizer in it a couple of weeks ago and wants to know when he should use his weed and feed? Also, what type of care would he need for shrub roses he just planted this spring?

A: It would be best to just use a 2,4-D product anytime now and wait until the end of May to do another application of straight fertilizer to get through the summer, since he already applied fertilizer with his crabgrass control. The best thing for the roses would be to ensure that they are kept well-watered but not overwatered.

8. A gentleman has Philodendrons and Crotons as houseplants that he has moved outside for the summer. Now the leaves on the Philodendrons are curling up, why is that? Also, what kind of care should be given to the Croton, is misting a good practice for them?

A: These plants are tropical plants that we can grow indoors in our homes. The nights are still too cool for those, which is why the Philodendrons may be having leaf rolling issues. If the weather is predicted to get to the low 40’s to 30’s for the overnight hours, it would be best to bring these plants indoors. The Crotons should be watered properly from the base of the plant to ensure survival. Misting plants leaves the leaves wet which can lead to diseases.

Houseplant

Philodendron picture by Soni Cochran, UNL Extension in Lancaster County

9. What can be done to control ants found in the kitchen?

A: Terro ant baits work the best with the odorous house ant. Also, seal up all cracks and crevices in the foundation and around doors and windows. Clean up plant debris outside the home near where ants are found inside the home to reduce locations where ants may be hiding outdoors.

10. A lady has blackberries that are overgrown. How can she clean them up?

A: Cut out the old stems that are existing and continue to do this at the end of every growing season.

11. This caller has a 30 year-old pear tree that has never produced fruit. She has one pear in her landscape. Why would it not produce fruit?

A: Pears are not self-pollinated. Plant another variety and it should begin to produce fruit.

12. When is the best time to prune a snowball bush?

A: This is a spring blooming shrub, so it is best to prune it immediately after it has finished blooming for the year.

13. This caller wanted to know how to control Dandelions in her yard?

A: 2,4-D products can be used now but will have the best efficacy in the fall. If applied now, ensure that the wind is not blowing and the temperatures are at or below 80 degrees Fahrenheit for the day of application and the 2 days following.

Photo by Nic Colgrove

Photo by Nic Colgrove

14. This caller has started tomatoes and peppers from seed indoors and they are now becoming tall and spindly. What would cause that and when can they be placed outdoors?

A: They will need more light to avoid becoming tall and spindly. Also, be sure to buy clean and sterile soils for seedling production to avoid problems with Damping Off, a disease common to seedlings. Summer crops can be planted outdoors in the beginning of May, typically Mother’s Day is a good date to plant summer vegetable gardens.

Yard and Garden: April 10, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for April 10, 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: Dick Campbell from Campbell’s Nursery in Lincoln, NE

1. The first caller wanted to know when to trim trees?

A: This depends on the type of tree to be trimmed. Oaks should not be pruned from April 1 through mid July to avoid susceptibility to Oak Wilt, a deadly disease that affects oak trees. Maples and birches will bleed sap excessively if pruned right not. This bleeding is not damaging to the tree, but it can be messy. Otherwise, it is good practice to prune deciduous trees during the dormant season so you can see through the trees to any crossing branches and air flow through the canopy.

2. This caller has a peach tree that produces too well. He wanted to know how to make the tree produce less fruit?

A: Fruit thinning should occur on fruit trees to help avoid branches breaking later in the season if they get too heavy due to fruit. The fruit on any fruit tree should be spaced 6-10 inches apart, leaving only one fruit on the branch every 6-10 inches. This will give you nice sized fruits that will not weigh down the branches.

3. A gentleman has ash trees that are loosing bark off the trunk. What would be causing this and how can it be fixed?

A: This could be caused by frost cracking. Frost cracks occur due to rapid temperature changes during the winter months. There is no cure for a frost crack and they may never heal over. Some trees may be able to close this wound, but if not it is an area where decay can enter the tree, as well as insects and diseases.

4. This caller uses ammonium sulfate on their lawn. Can this harm his lawn?

A: This can be harmful to the lawn, if the fertilizer is not spread uniformly throughout the lawn. If it gets concentrated too high in one are of the lawn, a burn can occur on the turfgrass. Otherwise, it will work fine as a quick release fertilizer.

5. Another caller has a steep slope in full sun in his lawn. What is a good perennial groundcover to use that does not have to be mowed?

A: Buffalograss is a good low management, perennial groundcover for full sun that wouldn’t have to be mowed. There are a lot of new varieties to choose from including, the newest from UNL, Sundancer Buffalograss that is darker green, has a denser canopy, and establishes faster. For more information on buffalograss care, see these UNL NebGuides: Establishing Buffalograss Turf in Nebraska and Management of Buffalograss Turf in Nebraska 

6. This caller had old Lilac bushes used as a hedge. She had cleaned them up and noticed there was a lot of dead branches and some new growth of branches. What should she do to clean them up and get them growing nicely again?

A: Prune out the dead canes, leave as much of the new, healthy growth as possible this year. Over the next few years, she can prune more of the larger, older canes out to bring it back to healthy growth. Don’t use a rejuvenation pruning with these lilacs because the older they are the harder it is for them to come back from such a drastic pruning. Watch out for borers and use systemic insecticides if holes are found at the base of the shrubs.

7. This caller had locust trees in the roadside. What should she do to get rid of them?

A: Cut the trees down and do a stump treatment with herbicides labeled for use on trees in a roadside.

8. A caller wanted to know what to do when planting new strawberry bushes and if they can be planted in containers? He also wanted to know what to do with shrub roses that grew taller than they should have, how much can he prune off of those roses?

A: Plant the strawberries to where the crown of the plant is just at the soil surface. Plant them 1 foot apart within the row and space the rows 4 feet apart. After planting you can use a pre-emergent herbicide on them to reduce weeds. Yes, they can be planted in a container, but that container will need to be protected through the winter months to get the strawberries to overwinter. As for the roses, you can cut those back to 6-8 inches tall rather than just taking a few inches off of the top. This will give you new growth that will produce more flowers throughout the entire shrub rather than some flowers just on the ends and sides.

 9. This caller had bagworms on his blue spruce in the past. He has now noticed that the top few feet of the spruce has died. Is this due to the bagworms? How can this be fixed?

A: This would be from a fungal disease called canker that is very common to spruce trees. From the point of the canker and anything above it, the tree will die and sap will flow from that canker location. There is no cure for canker, but the infected area of the tree can be removed to a location below the canker. It may regrow a new leader, but it may also continue to grow with a flat top. Bagworms can be treated with Bt, carbaryl, permethrin, or malathion around the third week of June or when the bagworms are immature and crawling around on the tree.

10. A caller wanted to know when to prune shrub roses? She also has a weeping white birch, when should this be fertilized?

A: Shrub roses can be pruned now. The weeping white birch should be fertilized just before they start to send sap up throughout the tree, which will begin soon. Watch all birch trees for borers, as this is a common pest in birches. Systemic insecticides, such as those containing imidacloprid, can be applied in the spring to help with borers in the tree.

11. This caller had apple trees that are 15 years old. When should they be sprayed for insects and diseases and what should they be sprayed with?

A: Orchard fruit tree sprays can be applied to all fruit trees. These have an insecticide and a fungicide to help with many problems that fruit trees face in Nebraska. This product should be applied at petal fall and every 10-14 days following. Be careful to not use insecticides on fruit trees while the flowers are blooming so no harm comes to the pollinators helping fruit development.

12. A gentleman wanted to know how to control Star of Bethlehem?

A: Spray with a combination product, such as Trimec. September 1st would be the prime time to do this so that the chemical will be taken into the bulb when the plant is taking nutrients into the bulb to help it get growing the following spring.

Pruning Fruit Trees in Late Spring

Flickr image courtesy of Alice Henneman per CC license

Flickr image courtesy of Alice Henneman per CC license

Fruit trees can be a lot of work to keep them producing well throughout the growing season. One of the most important activities to do for high production from your fruit trees, is pruning. Pruning is important, but it also must be done correctly to ensure healthy trees.

Pruning of fruit trees is best completed at the end of February and into March, when no leaves are present on the tree. Pruning trees in the spring allows them to heal the wound and put on new growth early in the spring when the weather is more enjoyable and not so hot and dry.

When pruning a tree, do not prune more than one-third of the tree off in one growing season. The tree needs to retain enough leaf area to produce enough sugar to compensate for the loss of limbs. Also, do not cut off branches that are one-half the size of the trunk or larger. This is too large of a wound to leave on the tree; it won’t heal correctly and can lead to decay in the tree.

For basic fruit tree pruning, start by removing any dead, diseased, or damaged branches. Next, prune out any water sprouts, which are branches that shoot straight upward off of the main branch. After that, remove any crossing branches and those that are growing weakly. Crossing branches can rub on other branches, which can lead to a wound on the branch where diseases and insects can enter the tree. Branches that are growing weakly are those that have a narrow crotch to the adjacent branch or growing closely parallel to other branches. Narrow branch attachments are weak and can easily break in storms, which would cause more damage to the tree.

If the pruning has been neglected for a few years or more, it will take multiple years to get it back to a healthy branching habit. If pruning on a fruit tree has begun at the beginning of the life of that tree, it will be easy to just prune a few crossing or damaged branches and a few small branches for airflow every year to keep it healthy and productive. However, a neglected tree can be brought back to good health with pruning over a few years.

Photo courtesy of Kim Todd, UNL Department of Agronomy and Horticulture

Photo courtesy of Kim Todd, UNL Department of Agronomy and Horticulture

When pruning, be sure to use the correct tool for the job. You can choose between hand pruners, loppers for larger branches, and handsaws for the largest branches. Use the smallest tool you can for the job. If you use a handsaw on a half-inch twig, you may tear the branch and it won’t be able to heal correctly. Also, make sure your pruners are sharp and clean. If you are pruning any diseased branches, dip the pruners in a bleach water solution to reduce the spread of the disease to other trees or throughout the infected tree.