You are here: Home Columns Hortiscope Hortiscope
Document Actions


Ron Smith answers questions about flowers, trees, gardens and shrubs.

By Ron Smith, Horticulturist

NDSU Extension Service

Q: I have two apple trees. On one tree, 10 percent of the leaves have turned brown and died. This tree had fire blight at one time. The other tree has a few leaves that have turned yellow and died. What is the cause of this and what can I do to save one or both trees? (email reference)

A: This is nothing to worry about. This is like losing a few hairs off your head and thinking immediately that you are going bald. A 10 percent or occasional yellowing of the leaves on any tree is normal and not harmful. This could be the normal senescence of older leaves or an indiscriminate feeding that took place at the juncture of the leaf petiole by mites. In either case, unless it starts becoming widespread, it isn’t worth worrying about.

Q: I have plum trees with fruit that are one-third to one-half the size of regular plums. The plums also are turning a bluish red and falling off. They have brown coloring on the flesh next to the pit. (email reference)

A: At this stage, there is nothing you can do. The plum trees likely will drop their fruit prematurely. If the plums remain on the tree, pick them off and dispose of them. Clean up all the fallen fruit and foliage this fall. This is a brown rot fungus that can be carried over to the following year. Protect the fruit next year with timely sprays of a fungicide as the flowers begin to open. Fungicides such as Benomyl, Chlorothalonil or Triforine will provide protection when label directions are followed. Examine the tree this fall when the leaves have dropped and make a note to remove any infected or cankered stems while everything is dormant.

Q: I planted asparagus this spring by digging a hole 8 inches deep and then covered them with 2 inches of dirt. As they grew, I covered them with more dirt until the ground was back to its original level. I cut them off at ground level and it took two weeks for them to grow back. Was that a mistake? They are at the point where I could cut them again if that is what should be done. I have been given conflicting advice. One party said to cut them down, while another said not to. What should I do? (email reference)

A: Asparagus needs to produce fern growth each year after being harvested. This carries on photosynthesis for the spears you want to harvest the following spring. No matter who tells you otherwise, don’t cut those down.

Q: Can Roundup have a carryover in the garden, especially for peas, strawberries and raspberries? If so, for how long? (email reference)

A: Unless they have changed the formulation of Roundup to be soil active, it should not have any carryover whatsoever. That has been my experience in using it. If you wait a growing season before replanting, you should be absolutely safe with the market formulation of this product.

Q: Will you give me permission to murder my husband? He sprayed a herbicide to kill a few lawn weeds in our backyard. However, the drift impacted 22 of my tomato plants. This isn’t the first time he’s done this. You’d think that after 22 years of marriage, he’d know how I feel about herbicide use! I even stole it from him, but he went out and bought some more. When I confronted him about this a day or two ago, he denied having used any herbicide. However, when I showed him a dead weed (and surrounding grass) where he applied the herbicide, all he said was: “I can’t believe that little bit of 2,4-D would cause that much of a problem.” So the guilt is there with my tomatoes and my hanging baskets. I’d like to murder him and bury him in my garden for use as a fertilizer. (telephone reference)

A: While I’m not an expert on justifiable homicide, I would think that after being married this long and knowing how much you cherish your tomatoes that he would have known better than to try to get away with something like that. A few weeds in a lawn are not going to hurt anything, but his obvious use of the 2,4-D herbicide will, and did. Add to this the fact that he tried to lie his way out of this criminalizes him even more. I think this is something that needs to be addressed with a lawyer present, along with some counseling by a psychiatrist. Let me know what you find out. However, let’s get back to what I’m an expert at. The tomatoes are not going to recover and should be pulled out. At this late date, planting and getting a successful crop of any consequence is very questionable. You would be better off purchasing your tomatoes from a farmers market.

Q: I am interested in taking cuts off of Russian olive shrubs to transplant into hedge rows. What would the procedure be? (email reference)

A: Are you sure you want to propagate Russian olives? Think it over carefully before doing so because there are a lot of problems associated with this species. They can root from cuttings taken in October and treated with a rooting hormone. The success of such attempts is 20 to 25 percent under ideal conditions. Seed is the preferred method of propagation, but the seeds need stratification for 60 to 90 days at 41 degrees F before planting.

Q: We have two cedars (Thuya occidentalis) in our backyard that are about 5 feet tall. We are building an extension to the house so they'll be in the way. Can they be moved? If so, when is the best time to do the transplanting? Thanks. (Ottawa, Canada)

A: The best time would be this fall, but I assume you are not going to wait that long to get work done on your house. Give the cedars a good soaking a full day before you move them. As the sun is setting the next day, dig the trees up and take as much of a manageable rootball as you and another person can handle. Once transplanted, give them a good soaking of water. Watch them for the remainder of the growing season to make sure the roots don’t dry out. However, don’t overwater to the point of keeping the trees in puddles.

Q: I have a question about some vines mixed in with my blue spruce trees. Last year, I noticed huge vines climbing on the trees. I cut them almost to the ground and put salt on them so they would decay (based on some naive advice). However, they have re-emerged and may be even stronger. I visited a local store to see if there is any chemical I could spray to kill them. They warned me about the possibility of harming the trees as well. The best I can do is pull the very tiny vines out of the ground. What can I do to get rid of those thick vines that are more like small trees? (email reference)

A: Whatever those vines are, try to control them by again cutting them to ground level. After that, paint the cut surfaces with a broadleaf herbicide or with Roundup. This will confine the damage to the offending plant and not harm the desired woody plants. Depending on the vigor and species of the vine, this treatment may have to be carried out more than once.

Q: I have a client with a lawn that is under a few different stresses. The owner suspected grubs because of some of the patterns in the lawn. She pulled some of the sod back and found a few dead grubs, so she treated the lawn last week. The lawn was sodded is 2006. The whole lawn feels like a carpet. When you pull on the grass, it doesn’t feel like it is rooted very well. There seems to be a big barrier between the sod line and the soil line. I’m wondering if it could be in relation to the peat sod problems you are seeing in Fargo. The soil is a sandy loam. They did haul some manure in before they sodded. I took a soil sample because the client was concerned about the pH level. Any suggestions on other issues to test for? The lawn appears to me to have a fungal problem. The owner suspected dollar spot or brown patch after doing some Internet research. When I took the soil sample, I had a hard time getting the probe into the ground. Some spots felt a little like concrete, which surprised me in a lawn. I also came across a worm about the size of a pencil that looked like an overgrown army worm. The lawn recently was aerated, power raked and fertilized with urea. With the warm, dry weather, it seems like the disease pressure is letting up, but the lawn is starting to show some drought stress because they have been watering less to avoid compounding the fungal problem. (email reference)

A: This lawn is in a very bad way because of a massive dormancy or death of the grass in large areas, excessive thatch or mat problems and grub feeding. The recommendations I’m going to give are not what the client will want to hear. Do a core aeration followed by dethatching with a power rake. This will make a horrible-looking mess that will need to be cleaned up. Run the mower over the area with the bagger attached to pick up the debris or rake everything up. Overseed the lawn at 2 to 3 pounds per 1,000 square feet using a mixture of Kentucky bluegrass, creeping red fescue and perennial ryegrass. After that, apply a starter or winterizer fertilizer. Do all of this around or just after the Labor Day weekend. The lawn will look like a patient just coming out of open-heart surgery but still surviving. The grass will recover if adequate moisture is supplied by Mother Nature or a sprinkler system, or both. Failing to do this will result in continued dissatisfaction and increased frustration with the lawn. These procedures, while resulting in a dramatic impact at first, will solve the problems. I also would recommend that the lawn mower blade get sharpened at least once a year.

Q: We have a dogwood in our yard. It was doing well for the last three years when we moved in. However, the tree is struggling this year. Most of the branches do not have leaves and the ones that do are turning brown on the edges. The only thing I could think of is that the damage was done when we were hit by hurricane Irene last year. The yard was flooded with less than 2 feet of seawater. Could this have affected the tree this hard? If so, is there hope for it? What should we do? (email reference)

A: The dogwood probably is history. It is slowly dying from the root system being immersed in seawater. That and the remaining salt toxicity is what are finishing off the tree. If it does recover or survive, it will not be the tree you want from an ornamental standpoint. I’d suggest removing it and getting it replaced with another when convenient.

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 For answers to general horticultural questions, go to

NDSU Agriculture Communication – July 11, 2012

Source:Ron Smith, (701) 231-7971,
Editor:Rich Mattern, (701) 231-6136,
Renewable Accounts: Renewable Accounts: E15 fuel could help you, the environment and N.D. farmers  (2019-06-06)  The EPA now allows E15 fuel to be sold year-round.  FULL STORY
Prairie Fare: Prairie Fare: Inspire Your Menus With Fresh Basil  (2019-06-20)  Herbs such as basil flavor food without you having to add salt to recipes.  FULL STORY
Use of Releases
The news media and others may use these news releases in their entirety. If the articles are edited, the sources and NDSU must be given credit.

Powered by Plone, the Open Source Content Management System