October 9, 2003

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I would like your recommendation about a crab apple tree that we hope to plant near our house. I have a spot that is approximately 20 feet by 20 feet with the property line fence on the north side, my house on the east, a deck attached to another portion of my house on the south, and part of the same deck (L shaped) on the west. We would like something that has a shape that would fit into the area and not over-power the house. We would like something that has nice flowers, holds its fruit to avoid a constant mess, has small red fruit and preferably red leaves as they age towards fall. I would appreciate any advice you could give us on what would be hardy for our area and come close to what we would like in that type of tree. (Grand Forks, N.D.)

A: The one that comes to mind is the thunderchild crab. It gets 12 to 20 feet tall, has nice pink flowers, deep purple leaves and small, persistent fruit.

Q: Would you refresh my memory on distinguishing perennial ryegrass and tall fescue? (Minot, N.D.)

A: Ryegrass has clasping auricles; tall fescue does not. Ryegrass is heavily veined on the upper surface and glossy on the under surface. Generally, tall fescue will be coarser textured, while perennial ryegrass is fine textured. Both do not produce rhizomes or stolons.

Q: I have a kolanchoe plant that I set out this spring that has refused to bloom. I would appreciate information about preserving it this winter and getting it to bloom. (Pembina, N.D.)

A: It could very well be that you have a succulent type that produces no flowers such as the kalanchoe tomentosa. The flowering types are naturally long-day (short night) plants and will commonly flower in the spring or under 14 hour days.

Q: My friend gave me a ficus tree about a year ago. Since then it has dropped nearly all of its leaves and the remaining ones are drying up and turning brown. While reading about ficus I recognized the brown shell bug description. I noticed it several months ago but thought it was dried sap. Now, looking at the tree, it has a lot of what looks like brown oyster shell scale. Is there any hope? Should I just dump it? (E-mail reference)

A: You will have to be the one to make that decision. If it is as bad as you say, then dumping it is probably a good idea. If the scale is concentrated on the upper branches only, then cut those back well beyond the infestation and spray the remainder of the plant with insecticidal soap to kill any crawling nymphs and see if it re leafs for you.

Q: This spring we planted some Nashville and Newport shrub roses and weigela bushes in the landscape rock surrounding our house. They are planted on the west and northwest side of our country home and will catch all of the cold winter winds. We want to try to help them make it through the winter and are planning on using hay to cover them. However, we are not sure about the pruning. All of the shrubs did well. Should they be pruned back after they go into dormancy this fall? Also, how do you recommend pruning 3-year-old spirea bushes? (Aberdeen, S.D.)

A: I would hold off on the pruning this fall as they will not have time to heal sufficiently. Do your pruning next spring in late March or early April. Concerning the spirea shrubs, I would selectively prune out the oldest canes as far back as possible, but no more than a third of the canes.

Q: At Christmas last year I was given a poinsettia plant that was small, but I kept it going and put it outside this spring. It has beautiful leaves so I brought it into the house before the frost the other night. What do I have to do with it to keep it from losing its leaves and how do I get it to bloom? (Fargo, N.D.)

A: Begin giving it long nights by covering the plant starting Oct. 1. Make sure the daily period of darkness is 13 hours or longer. The rest of the time, give it good direct light in a south facing or west facing window. If that is not possible, place it under a grow light. Keep it watered and sometime toward the end of November you should see the top leaves beginning to color up for you.

Q: I have a rose bush that I planted this spring. I noticed earlier that something was eating the leaves and used some Bug B' Gone spray on it. It helped for a while, but this week I noticed that the leaves are almost completely eaten. What is eating the leaves? The roses themselves are gorgeous and abundant. Should I continue using the Bug B' Gone or is there something better? There are lots of rabbits in our neighborhood. Could they be the culprits? (Jamestown, N.D.)

A: Absolutely it could be the rabbits! Spray some hot pepper spray on the plants and that will keep the little bounders from eating your roses.

Q: Last spring my husband and I landscaped our new yard using potentellas, a pink spirea, a rose bush, barberrys, salvia, Stella d' Ora daylilies, irises and day lilies. In the fall my mom cut everything down to the ground except for the potentellas. This spring the only plants that came back were the potentellas and the Stella d' Ora daylilies. The local nursery said barberrys and irises, daylilies, etc. are very hardy and don't usually die like that. I told them how my mom cut them down and they thought that might've been the problem. This year we re planted and used another pink spirea, more barberrys, irises, daylilies, salvia, a rose bush and a wiegela. Should I leave them alone this fall and winter? I'm scared to trim them. (E-mail reference)

A: Leave them alone and take the pruners away from your mom. Save the trimming for next spring.

Q: I just purchased a new house that has a flowering crab in the front. It’s about two feet from the house. Is it planted too close to my foundation? (E-mail reference)

A: You have nothing to worry about unless your foundation is in bad shape.

Q: Whenever we have roses in our home our cat seems to obsess with ruining them. He bites the end of the blossom just enough to cause serious damage. He goes to great lengths to get at them. Any thoughts on why he does this? Is there anything we can do to prevent it other than isolating them in another room? (Fargo, N.D.)

A: I have three cats at home and two of the three obsess over any flowers I bring my wife. We have to keep them away from the flowers or else they knock over the vase and go after certain flowers and ruin the whole arrangement.

Q: I have a rose plant that for the past few years has not bloomed. I don't know its past history because I have only lived here the past two summers. The growth is very prolific but I have yet to have a single blossom. I have several other rose plants that are doing fine. Would you happen to know what the problem might be and how I can correct it? (E-mail reference)

A: From your description, it is probably growing from the rootstock only, so it will not produce a flower. I suggest digging it up and replacing it with a fresh plant.

Q: I would like to know how to mow my lawn this fall. Should I mow it at the usual height I used this summer or should I cut it lower? (LaMoure, N.D.)

A: Generally, with the last mowing of the year, cut it about one-inch shorter to remove excess foliage and keep snow mold from forming.

Do you have a gardening or houseplant question? Write to Hortiscope, Box 5051, NDSU Extension Service, Fargo, ND 58105 or e-mail to Ron Smith at ronsmith@ndsuext.nodak.edu. Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations.

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Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu