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Ron Smith, NDSU Extension Service, Published June 14 2012

Hortiscope: Replacing tree best option for root damage

Q: I love your articles, and thank you for your time. We own a ranch in Wyoming on the Nowood River bottom, but the house sits up above overlooking the ranch. I transplanted some of the native cottonwood trees last spring from the bottom and put them up by the house. The soil is rock and clay. However, one tree is not doing well. It has leafed out, but the leaves are very small and don’t appear to be getting any larger. Do you have any ideas what the problem could be? (email)

A: This possibly would indicate root death or decline. The tree is using energy stored in the branches and trunk to produce the leaves. Without more energy reserves surging from the root system, the tree likely will expire in a few weeks. This could be due to root damage during the move, a girdling canker at the crown, root-feeding larvae (not very likely) or being planted too deeply. In this instance, there is virtually nothing you can do to save the tree. If it is going to recover, it will do so on its own, so don’t waste your emotional energy or financial resources attempting to save the tree. Simply remove it and plant another.

Q: I found a tiny evergreen under my deck several years ago. We think it is some type of spruce. I planted it in my flowerbed and it is now a beautiful tree. We would like to transplant it to another part of our yard but are not sure when or how to do it. Is now a good time? How deep do we need to dig to get all the roots, or is it better to have someone move it using a tree spade? I have learned a great deal from your columns, so any information you can give me to keep it growing would be great. Thank you for your help. (email)

A: It is better to have it dug up using a tree spade but do it later in the season, such as early fall or right after the Labor Day weekend. That will give the roots a chance to become established before winter closes in. By then, the plant should be toughened off enough to not react sensitively to being moved.

You want to give it every advantage to survive now that you’ve been successful at getting it to live this long.

Q: The other day, my daughter gave me a bag of tulip bulbs that her company pulled out to throw away. I have the bulbs in boxes in my garage to dry out. I hope the leaves will turn yellow so I can cut them down and store the bulbs until fall. Is this the correct thing to be doing? (email)

A: You and your daughter must live in the South. You are half correct when you say you want the foliage to turn yellow. However, it must be done in sunshine while they are still green to make food for storage and growth next year. If you can, pop them into the ground somewhere to allow them to yellow naturally. After that, dig them out to set them where you want. If you don’t have freezing weather where you live, you will have to refrigerate them during whatever you call winter in your area to prime them to bloom next spring.

Q: I have a 10-year-old Princess Kay plum tree in my front yard. The tree was beautiful until last spring. Normally covered with blossoms, the tree had only a few this year. The leaves also were sparse, and some branches didn’t have any leaves. The bark turned black on those branches. The trunk has ooze coming out and the bark is splitting and loosening. Is there any chance of saving this tree? If we do have to remove it, what can be planted in its place? We love the tree because it attracts birds and butterflies, smells wonderful and is the perfect size. (North Dakota)

A: You are right when you say the Princess Kay plum is a very worthy plant to include in a northern landscape situation. I believe your poor tree was besieged by all the negatives Mother Nature could throw at it in the past, such as record snowfalls, flooding and almost biblical rains. All of the above stresses and then some will attract insects and pathogens, such as borers, cankers and possible vascular wilt, to take up residence in this plant. To directly answer your question, I would encourage you to replant this beautiful tree. Nothing else can introduce a North Dakota spring with more majestic beauty than this tree when it is in full bloom. I would encourage you to look around for a full-sun location and make sure the site drains well. It is almost never a good idea to replant in the same location with the same species of plant. Doing so is like sleeping in the same bed after someone died in it from bubonic plague.

Q: I have a mature cottonwood that is the centerpiece of my front yard landscaping. I love the tree but am always afraid it’s not healthy. For the past few years, I’ve noticed a decrease in leaf production, compared with trees that seem to be in far less appropriate places. I know they need water and finally have figured out what I have to do to keep the leaves it does have on until at least the end of August. This year, I haven’t had as much cotton as usual. Is that a sign that something could be wrong? Thanks for any advice you can give me about how to keep this great tree alive and well. (Austin, Texas)

A: I’d strongly suggest that you get in touch with your Texas Extension Service county agent. An agent can be located by going to http://counties.agrilife.org/.

If that goes nowhere, I’d encourage you to contact an International Society of Arboriculture certified arborist. To find one, go to www.treesaregood.com/findtreeservices/FindTreeCareService.aspx and provide the needed information. A mature cottonwood tree can be a hazardous thing of beauty. It is best to have it completely checked out for soundness and any other potential problems that could spell the demise of this tree you love so much.

Q: I am interested in the variety of honeylocust you recommended in a couple of columns. My mother is interested in replacing several trees she lost to high winds last year. She would like a tree that provides light shade, grows fairly tall and is somewhat fast-growing. Any recommendations? Thanks for any information you can pass along, and I never miss your great column. (Grafton, N.D.)

A: This would be the northern acclaim honeylocust. It is an NDSU introduction by Dale Herman. It is a fast-growing, drought-tolerant, thornless, seedless and beautiful tree. Another good one to consider is the Dakota pinnacle birch. It grows in a columnar, narrowly pyramidal fashion. The bark is a yellow white.

Both the locust and birch have yellow fall color.

Q: I always have known that you should not water the foliage of roses because it can create black spot diseases. However, I have about a half a city block that is lawn and rose garden. It has a sprinkler system throughout. Should I water only during the day? This area requires a great deal of water because it is so large. (email)

A: Get your sprinkler system heads reconfigured to not impact the rose beds. Any competent irrigation contractor can do this for you by doing a little repiping and resetting of the sprinklers so that the direct spray stays where it is supposed to, which is on the lawn. If for some reason that isn’t possible, then program the system to come on at about 3 a.m. so that the morning sun can dry the foliage before black spot fungus can develop. You would then have to get into the habit of applying fungicides on about a 14-day basis to the more black spot-susceptible varieties of roses. Look for products such as Fore, Rubigan or Funginex. In the fall, strict sanitation will go a long way in keeping this pesky disease under control. Clean up all leaf and cane litter and cut the canes back in the early spring. Look carefully on the canes for any evidence of diseased or damaged stock. If you find some, remove them carefully and then burn or find another way to get rid of them. Do not compost any diseased waste because the fungal spores will survive typical composting temperatures.

Q: I understand that weed barrier fabric used in fields and around trees to control weeds is a detriment to birds because they can ingest fibers that are too long, which will kill them. Also, I understand that the plastic material is a detriment to birds. Please explain because I think many people would appreciate the information. (email)

A: From what source did your understanding of weed control barriers being detrimental to birds come? I would sincerely like to know because this is something I have not heard of. Cars, planes, trucks and trains also are detrimental to the health of birds. So are the herbicides and insecticides that protect the crops from degradation and destruction. What is the alternative you are looking for? Organic controls? There are pesticides used in organic efforts.

Essentially, every action that is taken by human beings is detrimental to the environment and the animals that are within it. I’m not trying to be a smart aleck in responding to your inquiry, but I have nothing at this point to offer as a solution other than back-breaking work pulling weeds that would elevate the cost of produce for public consumption to near prohibitive levels. I’m all for good, healthy practices as long as there is a dose of common sense to go along with it. Help me out with what you are looking for and your source(s) of information so that I can review it myself and see if there is any validity to these claims. If there is, I’ll be among the first to admit it.

Q: Is there a herbicide that can be sprayed on broadleaf weeds that are growing in my tulip bed? I planted 660 tulips last fall. They bloomed great this spring, but the weeds got ahead of me. I think the manure I mixed with the soil had a lot of weed seeds in it. (email)

A: This should be a good lesson for you to never use manure on flowers. Every time I’ve heard of it being used, the end result is a tsunami of weed growth.

Surflan is the only herbicide that I can find that has tulips on the label for annual broadleaf control. If that cannot be located where you live, then all I can suggest is to wait it out until the foliage on the tulips turns yellow and then remove it. After that, spray the area with glyphosate (Roundup). You could do the spraying now, but you would have to devise some way of protecting the tulips to prevent spray drift from hitting them.


To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or email ronald.smith@ndsu.edu.