December 13, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I just put several daffodils under an evergreen tree that we have in the front yard. The branches had been taken off up to 6 feet off the ground (this was done by the previous owners). My husband is concerned that the flowers won't do well because of the acidity of the needles. Do I need to replant them to another spot? (Moorhead, Minn.)

A: No need to worry. I have never known daffodils to be bothered by the effects of needle drop. They will do well, in fact beautifully, in such a setting.

Q: I have crape myrtles in a bed. They are about four or five years old and have been deep pink or red from the beginning. This summer they were very slow blooming and have changed to white. I also have a bush which was probably 60 feet from the bed of six crape myrtles and it too has changed colors. Could you tell me why this might have happened? (E-mail reference)

A: There is a first time for everything, and I guess this is mine for the crape myrtle shrub turning color! You must have different plants or they have different colors grafted on the same plant.

The only other possibility is that the crape myrtle is sensitive to soil pH changes, which again I have never heard of. Sorry I can’t be much help!

Q: I read an article about a way to stop potatoes from sprouting in storage. The answer was to put dried lavender, sage and rosemary in with the potatoes. Where can I purchase lavender? How much of each herb is needed? (E-mail reference)

A: Lavender should be available where you can find the other two herbs, which can be found at Sandie Shores, Herb's Herbs & Such, in Rochester, MN, phone (507) 753-3081, e-mail Mitakuye@aol.com . Everything is grown organically. As far as the amount of each goes, none of my references tell me exactly what that would be. I would assume a generous distribution to keep the volatile oils noticeable in the potato bin.

Q: I have a question regarding a Thanksgiving cactus. My wife has had one for 14 years and now it’s very droopy with very little vigor. We don't know if it will bloom this year. Is there anything you suggest? We repotted it a few years ago in good soil and compost. I promised her you would have an answer. (St. Paul, Minn.)

A: Boy, are you a brave man, promising your wife that I will deliver the goods. The pressure is too much! Here is what I suggest. Repot immediately in a very porous, peat-based mixture, to which you add very coarse sand or perlite in a free-draining pot. This should be done every year after the plant flowers. I suspect that the present soil mixture is water-logged, eliminating the necessary air the roots need to carry on respiration. Another possibility is the plant may have been exposed to too much direct sunlight over the summer. This is a jungle cactus, not a desert one, so it is a sub-canopy species in the natural environment. Filtered sunlight is the most it should ever receive. You might try watering (after repotting) with distilled or at least bottled drinking water that isn't too hard. These cacti do not do well on very hard water. Also, you might try misting the foliage with distilled water during the heating season to keep the humidity up around the plant. I hope something here helps. If it doesn't, it is likely due to a root rot disease that has set in. If that is the case, you will end up discarding the plant.

Q: My 92-year-old uncle has a question about a wild plum tree that grows behind his house on a bank of the Cannonball River in New England, N.D. In early September my husband and I picked a bumper crop of beautiful plums from this tree. Why does this tree only set fruit every 10 years? My uncle says that the last time he harvested fruit from the tree was about that long ago. The tree flowers every year. (Mandan, N.D.)

A: Fruit set on a particular fruit tree species is sometimes difficult. Many factors have to come together for pollination/fertilization to be successful. Maturation of pollen when the pistil is receptive; action of pollinating insects; lack of wind, rain, or cold weather, and certainly carbohydrate energy to actually produce the fruits. Often it depends on whether or not a cross-pollinator is close by and in bloom sequence and sexual maturity with the desired fruit tree. So, you can see that a lot has to be right for fruit set to be successful.

Q: I have a vine with bright red foliage coming up in a lilac bush. I've seen these before and thought they were pretty in the fall. Will it do any damage to the lilac, choke it or whatever? (Stirum, N.D.)

A: It is probably Virginia creeper, Parthenocissus quinquefolia. This is just a guess of course, but that has to be the most likely vine growing in our region that shows brilliant fall color. You can more or less confirm this by checking the leaves; if they are divided into five parts, then that's what it is. If they are not, then it is something else. These are very rambling, aggressive vines that could smother a shrub that it is growing on. I suggest removing it completely, or digging it out after it has gone dormant and transplanting it somewhere else.

Q: A gentleman told me he had read that there was a spray we can use on evergreens to seal them, basically to prevent browning of needles. I'm not aware of anything that can prevent environment damages, or is there? (Carrington, N.D.)

A: Yes, there is a material known as Wilt-Pruf on the market. There are others too, but this one is most common. Basically, they all work the same way; spray goes on milky, dries clear. It cuts down on desiccation throughout the winter, which prevents browning and dying of the foliage. It is also a good idea to reapply it in late winter during one of the thaws, as that is the time that most of the damage can be done--the air is warming, the foliage is warming and transpiring, but the soil and root ball are frozen and unable to translocate the needed moisture for replacement.

Q: I have a beautiful Autumn Blaze maple that is quite large (planted in the spring of 1995). The tree has grown very fast and always looked healthy. This summer the bark split open from near the base up to where the first branches start. The split is quite large and I am worried I could lose the tree in the future. What caused this to happen and is there anything I can do? The tree continues to appear healthy and is turning brilliant red now.

A: I am not sure what would have caused the split, but I can give you some possibilities.

A recent pruning may have exposed the bark that was shaded to direct or reflective sunlight on the south or west side. The split may have occurred in winter from the same effect of sunlight (known as "sun scald"). A "frost crack" could have developed from widely fluctuating temperatures. A sudden surge of growth could have taken place after an extended dry period was broken by a heavy rain. Last, although not likely, lightening could have struck the tree causing the split. If that were the case, the tree would be dead. The tree will generally heal itself. New bark tissue should be forming along the split which will compartmentalize the wound. You can aid it by wrapping the damaged area in burlap or some other protective material that is available at local nurseries.

Q: I recently found some apple trees in an old grove of trees and am wondering how to tell if the apples are safe to eat, or are all apples safe? Some of the apples are rather small and I am wondering if they are crab apples. Are all of those varieties all right to use in jelly? (Pettibone, N.D.)

A: I have never met an apple that hasn't been good to eat in one fashion or another. Enjoy. The mixture would make a good applesauce.

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