April 4, 2002

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have a weeping willow tree and two purple leaf plum trees that I would love to get more trees from. I don’t know how or even what it is called but I sure hope it could be done. I just would love to start some new trees from my existing ones. (E-mail reference)

A: Willow trees are very easy to propagate. Simply take some branches about pencil size or larger, about 9 to 12 inches long, and insert them into a sandy loam mixture, keeping them moist until a substantial root system develops. Purple leaf plums are not going to be quite as easy. Take cuttings in early June and try rooting them in the same media but under a mist system. If you can, get some rooting hormone powder and dip the cuttings into it before sticking. If these fail, don't fret; many before you have tried and failed. If fruit is available, remove the hard outer husk and plant this fall where you want them to grow.

Q: I was given a brochure about what I would call a "miracle grass" and asked if I could find out if it is, in fact legitimate and adapted to use in lawns in central North Dakota. The grass is Amazoy Zoysia Grass that is to be seeded as a plug in a grid pattern into existing lawns. It apparently is drought proof, heat proof, chokes out crabgrass, is wear resistant, winter hardy to -30F, grows in terrible soils, thrives in part-shade to full sun, ends erosion. I looked at their web site, but don't know if it is, in fact, legitimate. What can you tell me about this grass? (Napoleon, N.D.)

A: Just recycle the brochure. If it were truly a "miracle grass" I certainly would have everybody growing it in North Dakota. It is a warm season grass that does well in places like Oklahoma, Texas, Georgia and even New Jersey, but not here, I assure you.

Q: I have a prayer plant, bought one year ago in a little 2-inch pot. I put it in my restaurant on top of my water cooler. It grew and grew and grew. Then it began to bloom these little whitish flowers. I was told this was a sign of healthiness. It grew so large that it hung down about 2 feet all around the water cooler. Then all of a sudden it stopped flowering. I first thought that winter maybe that had something to do with it. Then I noticed that some of the leaves turned yellow. One Sunday I took the plant down and saw that where the plant crossed the edge of the pot and hung down, it looked like it was breaking. At that spot where it hung at the edge of the pot the plant stem looked like it was fraying like a rope does when it's going to break. I took the whole pot and broke it all apart. I got about 10 good pieces from it. All the little slips rooted and I've repotted the little ones in one pot. Now I'm afraid that it will do that again. What should I do? Everyone used to comment on that plant in particular. Should I get something to tie it up so it grows upward? Should I just let it grow down so it hangs but this time cut it back so it doesn't get to heavy and start breaking? (E-mail reference)

A: Just allow the plant to grow naturally, then as it begins to cascade over the edge of the pot, buffer it with a cloth or rubber edging of some kind to keep it from fraying the stems, cutting off those that get to be the longest and start the fraying process. Congratulations on having a great green thumb!

Q: I 'm building on a lot with over 25 years of growth and trying to incorporate as much as possible. I have some ash trees worth keeping, yet I may have to raise the grade. How much higher can I raise the soil until it causes the trees harm? At this point they have 10 inches of loam; then they hit clay. (E-mail reference)

A: Any kind of grade change will have an effect on the tree's vitality. With 10 inches covering the roots, the trees will likely die off over the next three to five years, being attacked by secondary pathogens and predators (boring and leaf-chewing insects), along with random die-back of branches. At this point, you need to get involved in vertical mulching with stone all around the drip line and beyond. This may do the trick, or it may not. Radial trenching may also be called for. Both processes are too detailed to explain here, but perhaps a local landscape contractor or arborist can help you. I would encourage you to make contact with a competent individual at your earliest to help you save any trees that are important to you.

A good reference is a booklet, "Tree Preservation During Construction," by Gary Johnson at the University of Minnesota.

Q: We are planning an outdoor wedding June 21. Can I start cala lilies indoors, and transplant them outdoors and expect flowers by June 21? Could I keep them in containers when I bring them outdoors? (Minot, N.D.)

A: That is too loaded a question for me to answer. I don't know how many calla lilies you are planning on, but if you want them to be in flower for sure, I would order them from a local florist, stating your desires. I would certainly recommend keeping them in containers for the wedding, and after as well. They make excellent houseplants from that point on.

Q: After going through cycles of the weather warming up and then returning to freezing temperatures, our burning bush had some branches that produced foliage last summer, while others remained bare. Can the whole bush be pruned back and when? (Webster, S.D.)

A: Yes, in early spring before it leafs out.

Q: I am a long time gardener who has enjoyed starting my own seeds. I have had good luck with tomatoes called "Super Fantastic." The last several years I haven’t been able to find the seeds. Could you give me some information on where I might purchase the seeds? Also, what kind of evergreen trees could I plant that would not harm the apple trees? (Wolsey, S.D. )

A: Tomato Grower’s Supply has the tomato seeds that you are looking for. Their phone number is (888) 478-7333. The seed is listed on page 11 in their catalog. Any evergreen would work except any junipers.

Q: Ten years ago, our son adopted a small two-leaf plant that was left in his new apartment. He has repotted it twice and it has now grown into a 4-foot by 4-foot plant with many 6- to 8-inch leaves on it. He keeps it by a picture window near a heat register and waters it daily. He found a marker with the plant that says it is a Brossaia Actinophylia. He would like to know if he is caring for it properly and, since the main stem is dividing, would it harm the plant to separate and transplant it? (Clear Lake, S.D.)

A: The fact that he waters it every day is an indication that it needs repotting, but not necessarily in a larger pot. Obviously he is doing something right to have had the plant so long and have it be doing so well. I advise against any attempts to divide it.

Q: I have a problem with grasses in my asparagus beds and my raspberry patches. I have heard that a herbicide by the name of Poast is effective in controlling this problem. Can you tell me if I can use it? (Richville, M.N.)

A: Poast is a very effective grassy weed control in raspberries. Here the basics: 1) Do not apply closer than 45 days before harvest. 2) It is effective only against actively growing grasses, with annual grasses being between 3 and 8 inches tall and quackgrass 6 to 8 inches tall at the time of application. 3) Use either a crop oil or a nonionic surfactant according to label directions.

Q: I planted a sweet potato in a flower pot. It has sprouted out all over the place and is growing fast. How do I plant it in the garden and where do the tubers grow? Also, can you stop an evergreen from growing up, up, up? (Jud, N.D.)

A: You really jumped the gun on starting the sweet potato this early! If you can keep it alive, plant the whole thing when the danger of frost is over. They will develop their tubers along the root system over the summer. In the future, simply plant the appropriate cultivar directly into the garden. I cannot accurately advise you on your evergreen question. There are pines, spruces, junipers, arborvitaes, firs, and cedars to name a few. I don’t want to give you a generic answer like "prune it" without knowing which species it is, as the timing and technique differs for each.

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