April 18, 2002

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: Does the Prairie Gem pear tree bear edible fruit? Or is the tree mainly for ornamental purposes? (Moorhead, Minn.)

A: The Prairie Gem pear is a beautiful ornamental pear. The fruit is not considered edible.

Q: A local person asked what type of grass he should plant for a grass runway (airstrip). Do you have any suggestions? (Linton, N.D.)

A: You want a low-maintenance, non-seed head forming type that can form a decent sod under widely varying conditions and recover from physical injury. Fairway crested wheatgrass, Agropyrum cristatum, is perhaps the best one to consider, as it competes well against weeds if it isn't overwatered, and not mown too short, keeping it between 3 and 4 inches. Seed at a rate of about 200 pounds per acre, getting a seed lot with a minimum seed purity of 85-90percent and a germination minimum of 80-85 percent. Others can be used, but none will adapt to our prairie conditions like this one.

Q: Last May I planted about 50 cottonless cottonwood trees around my property for a wind barrier. Only about five of them grew branches and got a larger base through the summer and fall months. Some look the same as the day I planted them while some broke at the base, and some were eaten by rabbits. Some broke half way down the base (trunk), and that is why I am writing this letter. I need to know how sturdy and hardy these trees can be. If the base gets snapped or eaten half the way down, will they continue to grow? And in regards to the trees that did not get much growth last year, were they possibly getting an established root system and will grow this year, or am I just wasting time and should plant new trees? I really do not know much about plants or trees but I think I planted correctly. I protected the roots and kept them moist until we planted. We dug deep holes and fertilized them and kept them watered. (E-mail reference)

A: My experience with cottonwood trees has been that once established, they are there in some form or other, for life and beyond. I would suggest giving these trees another year to shape up and show some vigor, then if not, recycle them and replant. With tree growth, how much energy is stored in the root system often determines whether or not they take off after planting. Of course, a tree may do a very good job of storing that energy, but then too much of the root system is removed in transplanting, setting the tree back for a year or so. Sometimes they can recover, other times they cannot. I would say that with this year, you will have given them ample time to recover from any transplanting shock. Don't make the mistake of over-caring for them. Give them water to keep them from dehydrating, but further fertilization should not be necessary.

Q: Three tears ago I planted Nanking cherries. They seem to be at a standstill. There are some that are now about 4 feet tall. They have never flowered. The rest are only about 1 1/2 feet tall. I do have a tin can around the base that I use for watering. Would this be hindering growth? When the taller ones got so far along I took the can off before I couldn't get it over the branches. (New England, N.D.)

A: I doubt the tin cans would have a negative impact on the plants, unless they were so pushed into the ground that they did some damage to the crown and some roots. However, I would still remove them this spring and see if you get the growth response you are looking for. If they show no inclination to take off and grow this summer, then the root system has been damaged some where along the line and they are not likely to make vigorous specimens.

Q: I read with interest the letter and comments regarding the Cyclamen plant. I, too, have had a Cyclamen (purchased from the florist) for three or four years now. It blooms profusely in the winter, and all with minimal care. During the summer months, I set it outside on the north side of the house. During the winter months I have it in a south window in my low temperature basement (50 + degrees). I also water from the top. Last fall I transplanted it to a larger container, and it has seemed to flourish. The foliage has never died back for me. (E-mail reference)

A: Thanks for your note. What I tell people who do what you are doing successfully is to ignore any advice to the contrary. Years of research can go into growing certain plants, books can be written on what plants require, and graduate degrees can be earned by studying the foibles of plant growth, reproduction, and crop yields and be absolutely correct. But nature is full of contradictions to the research. Right outside my office on campus, I am waiting impatiently for trees to die that should have died more than six years ago because they are completely surrounded by concrete and blacktop, defying the laws of requirements for plant growth: aerated soil, a balance of nutrients, light and water. Yet, they grow on every year as if nothing is wrong! Someday they will die, then I can say what killed them .... finally!

Q: I wrote to you last fall on how I should care for some new evergreens I planted. You said I could either protect them with burlap or let the snow cover them. I did the latter, but as you know it was kind of a bad year to let the snow protect them! I have two staggered rows of trees on the south side of the property (the trees are about 2 feet tall) and in between the rows (the rows are about 10 feet apart) we put up snow fence. Most of the wind we receive comes from the south with no protection from the wind, as there are fields across the road. It seems that the evergreens south of the snow fence, basically only the south side of the tree, have turned brown, while the ones on the north side of the snow fence have stayed green. Could it be from the wind? What can I do to help the evergreens this spring? For that matter, the rest of the year? (Glyndon, Minn.)

A: Browned evergreens at this time of year is not unusual, and in 90 percent of the cases recovery is complete. There is nothing you can do at this time or later to help them out, unless it turns out to be a dry spring or summer, then supplemental watering would be called for.

Q: We just moved to our farm here near Ellendale and want to plant some fruit trees and bushes What kind of apple trees would grow best here? I would also like to plant some gooseberries. I know gooseberries will grow , as a neighbor has an old one they would like to get rid of. The gooseberry bush, located underneath another tree, is around 50 years old and quite large. I know I cannot safely remove the entire plant without damaging the tree. The bottom of the bush, with all its branches, is about 3 feet by 3 feet. How much will I need to take to get a viable plant , and when would be the best time to dig them? Also, I have a chance to get some mature grape vines from a friend in Minneapolis. Will they grow here? (Ellendale, N.D.)

A: Plenty of apples: Hazen, Sweet Sixteen, Haralson, Fireside, Honeygold, Prairie Spy, State Fair and Redwell to give you some selections off the top of my head. Concerning the gooseberry bush, dig ASAP and get as much of the root system as possible, after cutting it back to about 4-inch stubs. Grapes will grow in North Dakota, but it depends on the variety. If the friend is willing to give you some canes to root and try, give it a shot. Your location is almost in what is considered the "banana belt" of North Dakota, so your options would be open for better selections than for much of the rest of the state.

Q: I am looking to purchase two crab apple trees for my mother this spring. She repeatedly tells me that Snowdrift crab apples make the best jellys and jams. However, as I've been researching them, many places tell me that Snowdrift crab apples are only for animal consumption. I was wondering if you could recommend different crab apple trees that would survive this weather, as well as taste great as jam. (Detroit Lakes, Minn.)

A: Listen to your mother. She is probably right! As far as which crabapples make the best jelly, I cannot say, but we have had excellent jelly from Dolgo, Centennial, and Chestnut. I suspect that the low quality rating of some of the crabapple fruit is due to the small size of the pomes, making them difficult if not impossible to convert easily into jelly.

Q: How do you propagate a crown of thorns? (E-mail reference)

A: New plants can be raised from short tip cuttings taken in spring and early summer. Use a sharp knife or razor blade to cut off growing tips about 3 or 4 inches long, and stop the latex flowing by spraying the mother plant with water and dipping the cuttings in water. Allow the cuttings to dry out for a day before setting them in a slightly moist, equal parts mixture of peat moss and sand or perlite. Do not let the mixture to become more than slightly moist; if too wet, the cuttings will rot without producing roots. Place the pots where they can get good bright light, but not direct sunlight, keeping the mix just barely moist, allowing the top two-thirds to dry before re-wetting. Rooting should take place in about six to eight weeks. Be careful in handling!

Q: I have about 700 peonies that are overrun with quackgrass. Mulching helps, but the quack is persistent. Is there a herbicide for quackgrass in peonies? (E-mail reference)

A: There is nothing listed that is selective, only products like Finale and Roundup, neither of which are selective. If there is some way you can protect the peony plants while applying these herbicides, you may be able to bring it under better control.

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: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu