Arbor Day, Plant for Diversity

As an arborist, trees are my favorite plants. And there is a holiday to celebrate my beloved trees, Arbor Day. Arbor Day is celebrated on the last Friday of April every year in Nebraska. This year that falls on April 24th. This holiday is not the same throughout the United States, it is moved around for other states to be in the best planting time for the year for each state that celebrates it.

Diversity

Deciding what tree to plant is very important and sometimes difficult. Diversity is key when choosing your tree. The general rule is to plant no more than 10% of a tree species, no more than 20% of a tree genus, and no more than 30% of a tree family in a respective urban area.

Diversity has not always been used as widely as today, and we have learned from that. In the early 1900’s American Chestnut trees were wiped out by Chestnut blight. We replaced many of those trees with American Elm trees which were then destroyed by Dutch Elm disease in the 1960’s. Those were then replaced with Ash trees which are now being demolished by Emerald Ash Borer. Also, in the early 2000’s we lost a majority of our windbreaks to Pine Wilt disease.

Diversity of our tree species helps reduce the problems from widespread disease and insect outbreaks. Look around at what types of trees you have and what types of trees your neighbors have before deciding on a new tree, try to avoid over-planting the same few trees throughout the neighborhood. Plus, diversity of trees is more aesthetically pleasing because of the different leaf and bark textures, different bloom times, and overall differences in trees.

Using understory trees

There are many trees that make a great understory trees and can be planted in the shade and protection of larger trees. Those trees would include things like redbud, pawpaw, and some of our dogwoods including flowering or Kousa dogwood. These trees prefer to have part shade so under a larger tree is a great spot for them. This can help mimic nature and help the overall growth of both the understory tree and larger tree.

Care of Trees

Keep newly planted trees well-watered. 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.

A 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. Mulch will also help keep weeds down and reduce competition of water and nutrients from turf and other plants. Mulch also reduces damage to the trunk of trees from lawn mowers and trimmers. Finally, organic 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 year to maintain an effective layer because it will break down over the growing season which will improve the soil.

Spring Gardening

Spring is a wonderful time of the year! After a long, cold winter, it is always so wonderful to be able to get outside again and start working in our gardens.

Care of Annuals and Perennials in the spring

If you didn’t clean your perennial beds last fall, wait until mid-April before you begin cleaning them in the spring. Those plants have been protected from the plant debris from last year’s growth, removing that before freezing temperatures and snow have subsided would expose the crowns and could kill the plant if cold temperatures return. You can begin to refresh your mulch anytime now. Apply 2-3 inches of mulch around your flower beds to protect them from weed competition and to keep the roots at a uniform temperature with added moisture.

When to Plant in the spring

For new annual or perennial plantings, wait until after the frost free time for the spring. For southeast Nebraska, this is late April to early May. Trees can be planted most any time that the ground is not frozen. Arbor Day is April 24, 2020 so anytime around then is a good time to plant a tree. Shrubs should be planted from April through May.

Vegetable Gardens

Vegetable gardens can be worked in the spring as soon as the ground is dry and workable. Cool season crops such as peas, potatoes, carrots, radish, kohlrabi, lettuce, and spinach can be planted now. Asparagus beds can be cleaned up now and new asparagus patches can be started. Make sure that the soil is dry before you work the garden or plant any vegetables. Planting into mud can compact the soil and disrupt the growth of plants.

Wait to plant warm season crops such as tomatoes, cucumbers, peppers, eggplant, corn and beans until after our average frost free date, which is the end of April for southeast Nebraska. I always go with Mother’s Day weekend for a good time to plant warm season crops because we often do still see snow in the first week of May which can harm tender transplants.

Vegetable gardens should be mulched in some way to manage weeds. Grass clippings make a good mulch as long as the lawn hasn’t been treated with any herbicides. If grass isn’t available or isn’t an option for you, you can use straw, newspaper, or wood chip mulch on the garden as well. Preemergence herbicides such as Preen can be used as long as it is labeled for use in the garden. Don’t apply preen around your seeded plants until they have emerged. Plants like beans and peas will need a trellis to grow properly and tomato plants and other tall, bushy plants should be grown in a cage to keep them from falling over. Vining crops, such as cucumbers, can be grown on a trellis if desired. This will keep the plants up with good airflow to help reduce disease and it will make harvest much easier. Be sure to water your garden if rainfall isn’t present. Gardens need about 1 inch of water per week for best growth. Soaker hoses and drip irrigation are the best options to reduce diseases.

Yard and Garden: April 26, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for April 26, 2019. 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 2, 2019. 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: Roch Gaussoin, Extension Specialist for UNL Agronomy and Turf

1. The first caller of the show recently applied a Weed-B-Gon product that contained crabgrass control. Now he wants to fertilize, but it is a fertilizer and crabgrass control together. Will it be harmful to put the crabgrass control on twice this spring?

A. That should be fine and you won’t see any injury from applying the crabgrass control twice this spring. You won’t need to apply any additional pesticides for the lawn this year. Next year, it would be better to do a little more planning ahead so you don’t apply the chemical twice so close together. This is just additional pesticides in the environment that are not necessary, so be careful with that in the future.

2. A caller is bringing in topsoil on a new build site. He needs to overseed, but is it getting too late to do that yet this spring?

A. Seeding the lawn will have the best results if done in the fall, but spring can get a good start on a new lawn. The weather will be the problem to lawns seeded too late this year. With the weather as it has been this year, there is likely still a 2-3 week window for overseeding the lawn with fairly good success. It might be a good idea to overseed now and then do another overseeding in the fall to thicken it up. Also, for weed control, it would help to use mesotrione (tenacity) at seeding. There is a starter fertilizer that contains the tenacity to help with start-up of the turf and to keep the weeds down while establishment occurs. It would just help to get some type of cover crop or turf down to reduce the amount of bare soil that weeds can grow into.

3. This caller has henbit. Would it be controlled well with the Tenacity? If so, should he use a stronger dose of the Tenacity because he has tried it with limited success?

A. It is Never a good practice to use pesticides at a higher rate than what is listed on the label. A lot of research went into finding the correct rate for best control of a pest. Henbit is hard to control this time of year, it is best controlled in the fall. It will die as soon as the heat of the summer comes on because it is a winter annual and doesn’t live well in hot weather. Treat in the later fall, October, with a 2,4-D product for best control.

That caller also has a peach tree that just flowered for the first time. It has two 2-inch long cracks on the tree trunk, each on opposite sides. What can be done with this?

A. Unfortunately this tree is not going to live long. There is nothing to do to fix the tree once cracks like this happen. This large of an opening is very damaging to the tree and will not allow the tree to live long. If it is out in the open where it won’t damage anything if it falls, leave it until it dies.

4. A caller has been trying to get a native grass prairie started for a few years now with limited success. He has a mix with Blue Grama, buffalograss, and little bluestem. What can he do to get it to grow better?

A. Don’t give up yet. Be sure to control the weeds with herbicides, 2,4-D won’t harm the grasses but will manage the weeds. After some photos, it shows that there is still some grass in there, but it is very early for these warm-season grasses. Keep mowing to keep the seed heads down for the weeds.

5. Can potatoes still be planted yet this spring?

A. Yes, get the potatoes in soon, and they should be fine yet this year.

What do you do for Pampas grass with a dead center?

A. Dig it up and divide it and replant it. This can still be done this spring.

She has a crabapple that has dead branches in it, can those be cut off now or should they be removed in the fruit tree pruning window of February-March?

A. Remove dead branches anytime of the year that they appear.

6. A caller wants to know when to spray for bagworms?

A. It is weather dependent. Starting in late May, check weekly for the small bags to begin to show up on the trees. When the small bags show up and until they are up to 1/2 inch in length you can spray.

He also wondered when and how to fertilize trees?

A. It really isn’t necessary to fertilize trees in Nebraska. They can get the nutrients they need from the soil naturally.

tree irrigationHow do you water trees that were recently planted?

A. water them one time per week with a slow trickle from the hose for about 20 minutes each time they are watered.

When is the best time to prune cedar trees to shape them?

A. Most anytime would be fine with a cedar tree, but the best time is in the late winter to early spring.

7. This caller has Austrian pines that are turning brown on the tips of the branches with short needles. What is causing this and how can it be controlled?

A. This sounds like tip blight. It can be treated now with a copper fungicide. A second application should be made 7-14 days after the first application.

8. What is the best thing to mulch asparagus with?

A. Grass clippings, straw, hay, or wood chip mulch can all be used to mulch asparagus. It would be best to hand pull weeds and then use preen that is labeled for use in asparagus before applying the mulch. If there is a problem with brome grass, use roundup carefully around the asparagus first as well. To carefully get the glyphosate on the brome and not on the asparagus either paint it on with a foam paint brush or use the “glove of death” which is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Glyphosate and rub those fingers along the stem and leaves of the bindweed to kill it.

9. A caller has been trying to start seedlings of spruce and fir trees for a few years with limited success. He thinks it may be due to root rot because when he pulls them up the roots look rotten. How can he get the trees to grow?

A. After discussion, it seems that he doesn’t overwater the trees and may in fact not be watering them enough. He also said that he can get the trees to grow in another, more neglected, location. It was suggested that he do a soil test to see what is going on with the soil in this desired location. It might be that there is a hard pan underneath these trees that is impeding water movement through the soil causing the roots to rot.

10. This caller has been trying to get grass started and is having difficulties. He has used an aerator, seeder, lawn roller, and then waters the seed well and it is not coming in very good.

A. It seems his practices are good, so he may try a soil sample to see what the nutrient and pH levels are in his soil.

11. The last caller of the day wanted to know what the difference is between a Sycamore and a London Plane tree?

A. These trees are 2 different species of very similar trees.

 

Yard and Garden: April 12, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for April 12, 2019. 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 2, 2019. 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: Stacy Adams, Associate Professor of Practice, UNL Department of Agronomy & Horticulture

1. The first caller of the show recently purchased a tree at a box store. Can it be planted now or should she wait?

A. If the tree is not leafed out yet, it would be fine to plant it outdoors. However if it is leafed out, like it turns out this tree is, it would be better to wait and put it in a shed or garage for a few more days to get through the cold nights we are supposed to face this weekend. Next week it should warm up to the 70’s and would be find to plant this tree outdoors.

2. This caller just recently moved into a new house. The yard at this house seems to have been neglected for a while and it is full of weeds. What is the best way to renovate this lawn? Should it be all killed and started again?

A. It would be better to just renovate what is existing rather than killing off the entire lawn and starting from bare soil. When the soil remains bare as new seed is started, many weeds will find their way back into the yard. A good way to renovate would be to aerate now and follow the aeration with an overseeding to improve the density of the lawn to help out compete weeds. When overseeding, a starter fertilizer can be used, there is one that contains mesotrione, a herbicide commonly known as Tenacity. This mesotrione will help combat the weeds and not harm the new seedlings. Then, in the fall, aerate and overseed again to help thicken up the lawn more. Next spring, crabgrass control can be used. Over time, the lawn will improve and weeds will begin to be reduced in population.

3. A caller has ash trees with holes in the trunk, mainly at the base of the tree. The holes are very small, maybe 1/16″. What is causing this damage? Is it Emerald Ash Borer? Can he save the trees?

A. These holes are too small to be Emerald Ash Borers (EAB). The holes for EAB are 1/8″ and they are D-shaped. With EAB, it is more likely that the damage and holes would start at the top of the tree and move their way back down the tree rather than just at the base of the tree like these holes are. This size of hole could be from a Bark Beetle. These are tiny beetles that can damage the cambium layer of our trees. Bark beetles can easily be controlled with a tree and shrub systemic insecticide containing Imidacloprid, which is common in the Merit products. For more information on the different types of insect damage, visit this page from the Nebraska Forest Service

bark beetle damage, whitney cranshaw, Colorado state Univ, bugwood
Bark Beetle damage, Photo from Whitney Cranshaw, Colorado State University, Bugwood.org

4. When is the best time to plant poppies and where should they be planted? She purchased seed and would like to plant it.

A. Poppies germinate best in cool soil temperatures, so anytime now would be a good time to get the seed spread. They need full sun, so place them in a garden that receives at least 6 hours of sunlight per day. Click Here for more information on growing poppies.

5. A caller has buffalograss growing, but it is fairly thin. What can be done to thicken it up?

A. Overseeding or adding new plugs will help to thicken the buffalograss. However, this is a warm season grass species so it should be seeded or plugged in later May to June. Fertilize should be added in the summer months as well, do not fertilize in the spring or fall when the plants should be going dormant. This guide will help, it is a Buffalograss Lawn Calendar from the UNL Turf Department.

6. The last caller of the day has Iris that was transplanted from her grandmother’s plants 15 years ago. She will now be moving sometime this summer how can she transplant these iris’ to ensure they live?

A. The best time to move Iris’ would be in the fall, but it can be done in the spring. Since you haven’t purchased the new home or sold this home, they can’t be moved now. It could be written into the purchase agreement that you can dig those up when the time is correct in September. If not, you can develop a nursery type of location. Dig them up now and put them into a cat box on the North side of the house at the new location until the fall planting time. For this spring, it would help to pamper the plants to help them with the move. Keep them watered through the year and fertilize them and cut off the flower stems before they set seed to help them put energy into the rest of the plant rather than seed production. If you have to move them in the summer, just make sure you keep them well watered.

Tree Selection and Pruning

2014-06-12 16.10.39

Arbor Day is Friday, April 28th, 2017. Arbor Day is always an exciting day for me because I really appreciate trees and understand the real potential that can come from planting a tree. With Pine Wilt and the concerns of Emerald Ash Borer creeping closer it seems there is always a need to plant a tree, if not for you, then for future generations.

There are a lot of good trees to plant when you do plant a tree. The most important thing to remember when planting trees, is Diversity. When you go to purchase your tree, look around your yard and even your neighborhood. Try to avoid planting multiple trees of the same species, genus, or family of plants in the neighborhood and in your own landscape. You may enjoy Maples, but you want to make sure you plant other types of trees in your yard besides just maples to help avoid an issue that may arise should another pest come through like what we saw with Dutch Elm Disease or Chestnut Blight or now Emerald Ash Borer.

2014-10-06 15.27.18

Each year, ReTree Nebraska comes out with a new diverse list of trees that grow well in Nebraska and are often under-utilized. That list includes Baldcypress, Catalpa, Kentucky Coffeetree, Elm Hybrids, Hackberry, American Linden, Sugar Maple, Chinkapin Oak, Bur Oak, English Oak, Sycamore, Shantung Maple, Miyabe Maple, Gample Oak, Tree Lilac, Concolor Fir, Black Hills Spruce, and Ponderosa Pine. In 2017, ReTree Nebraska added Turkish Filbert including other nut trees such as Hickory, Chestnut, Pecan, Buckeye, and Walnut to the list of good trees to plant in Nebraska. There are a lot of other great trees to use in your landscape, this is just a short list.

Turkish Filbert is a unique, under-utilized tree in Nebraska. It grows up to 40-50 feet tall and 30-50 feet wide. It has large, bright green leaves that turn yellow in the fall. This tree has catkin flowers, like a cottonwood.  It has edible nuts that are produced in a cluster of 3-6 and have a spiny husk that covers the nuts. Often squirrels eat the nuts, but they can be roasted and eaten by humans. This tree is most commonly used as a shade tree or a specimen tree in a landscape.

Another thing to think about with our young trees, is pruning. Eric Berg, a community forester from the Nebraska Forest Service wrote a great article on pruning young trees. We need to start pruning our trees when they are young to minimize tree wounding and cause the trees to grow stronger, mature growth. A tree planted in a landscape setting, rather than being planted in a forested area, will grow out more than up and not develop a strong central leader. Often our trees develop multiple leaders that lead to weak growth that can easily be broken in storms. We saw the damage from weak branch attachments and poor growth in our ice storm this past winter.

pruning tools-K. Todd
Photo courtesy of Kim Todd, UNL Department of Agronomy and Horticulture

We can prune a tree when it is young to help prevent some damage in future storms. If you would like to learn more about pruning young trees, Graham Herbst, from the Nebraska Forest Service, will be in Beatrice to teach us about pruning young trees on Monday, June 19th from 6-8 pm starting at the Gage County Extension Office. He will cover how to set pruning objectives, determining a pruning cycle and dose, strategies for specific trees, and how to execute your plan with proper cuts. There will also be a hands-on pruning demonstration at the end of the classroom portion. If you are interested in this program, please call the Gage County Extension Office at 402-223-1384 to sign up.