Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have a question regarding my Schefflera. My plant is healthy but one branch is getting tall (about 5 feet). I would like to prune it back, but want to re-pot the portion I'm cutting off. Is this possible, and if so how do I do it? The plant has three other branches that are lower in height. (E-mail reference)

A: I would suggest air-layering instead. This is a process where roots can be produced on plant stems above the soil and can be removed and potted up as a separate plant.

Our "Home Propagation Techniques" bulletin (NCR #274) describes in detail how to air-layer a houseplant.

Q: I have had my spider plant (which I started from another one) for about six months and it has been growing very well up until yesterday, when I noticed brownish grey spots in the middle of about three leaves. What can I do to stop this and what is it?

A: Where are you writing from? Who are you? I would appreciate knowing where your message is coming from, as your location can affect my advice. Your spider plant is probably suffering from overwatering or from too bright a light source. I'd bet on overwatering at this time of year, unless you are writing from South America or South Africa. They should be sparingly watered through our winter months. It wouldn't hurt to allow them to dry between waterings at this time of year. Related to watering is using water that is too cold. Allow it to reach room temperature for 24 hours before using on this or any other houseplant. As for the affected leaves, cut them out carefully -- the plant is a prolific producer of foliage and will quickly cover up any surgery you perform.

Q: There is an heirloom apple called Winter Banana. Description from AppleSource: A large, clear, pale yellow apple with a beautiful pink blush. Originated in Indiana in the late 1800s. Quality good to very good. Firm, coarse, distinctly aromatic. Often used as a pollinator for Red Delicious in Washington state. (E-mail reference)

A: Thanks for the info! Our reader will appreciate getting this, and along with that, I have learned something too.

Q: Are there any nut-bearing trees native to the Northern Plains? I understand by reading the bulletin by you and Dale Herman that both butternut and black walnut are not native to the region. What about hazelnut? If they are native, what is their preferred habitat? The only "nut tree" as such that I can think of at present is the bur oak. (E-mail reference, Grand Forks, N.D.)

A: Yes, the American hazelnut is native to our region -- in fact as far north as Saskatchewan, and as far east as Maine. They are found in the Turtle Mountains and along our eastern rivers. They grow as a shrub, getting about 8 to10 feet tall, but can get considerably larger if cultivated and given a milder climate. Heights in Ohio were more like 15 to 18 feet, and the spread was about two-thirds the height. You can expect about 25 to 30 pounds of seed for every 100 pounds of fruit collected. To germinate the seed, about two to three months of prechilling is needed. Nurseries meet this by simply sowing the collected seed in the fall before freeze-up. They germinate over a 60-day period, at temperatures ranging from a high of 86 degrees during the day to a night temperature of 68 degrees. They are an excellent source of wildlife food.

Q: I have two American chestnut trees that a friend from Green Lake, Wis., gave me about 15 years ago. He said they have them growing there and he wanted to see if they could take our winters. I really babied them and they died back once but are now 12 to 15 feet high. This past year, 2000, is the first year they bore nuts. That has been very interesting -- they are about the size of a golf ball with spiny stickers on them. When left on the tree, they eventually pop open like an X and the seed falls out. I planted some this fall. Could you send me some information on growing this particular type of tree? (E-mail reference, Dell Rapids, S.D.)

A: If they are truly the American chestnut (Castanea dentata), then you are among one of the more fortunate Americans to have a living, nut-bearing tree! The nutmeat is very edible for both wildlife and human consumption. Don't worry -- the squirrels pounce on them as soon as the prickly husks open, revealing the nut. They are perishable and should be harvested and consumed quickly or stored properly, but for not more than four to six months. Storage conditions should approximate the vegetable crisper of the household refrigerator- - temperature just above freezing and the relative humidity close to 70 percent. Anything significantly higher could result in decay.

As far as the trees themselves go, if they are the true American chestnut, their days could be numbered, but perhaps not, since you are outside what was once the natural range of this species. The fungus that came into the U.S. in 1904 kills without exception. If you wouldn't mind, I'd like to see a sample of the leaf when spring comes around. Allow them to open completely, then send me a small branch about 6 to 9 inches long, leaves attached. I'll key it out to determine whether it is the American or Chinese Chestnut. Send the sample in a ziploc bag, dry, in a padded envelope.

Q: I live in northeastern South Dakota and am considering starting blueberry bushes. I have a 40- foot garden and would like to know how far apart to plant them, and also the space required on the opposite sides based on the fact they would be planted in a row. I have a spacious garden and would appreciate your suggestion as to what variety or varieties one should plant. (E-mail reference, S.D.)

A: Here are the requirements for growing blueberry bushes in your part of the country:

1. First, get the soil tested, and indicate that the crop intended is to be blueberries. Since your soil is likely alkaline or at least neutral (pH 7), you will have to incorporate sphagnum peat moss and sulfur thoroughly into the planting site, prior to planting the shrubs.
2. Assuming you have a sandy soil or a loamy sand, and a pH reading of 7.0, you would need to apply 19 pounds of elemental sulfur per 1000 square feet, and 1.5 to 2.0 cubic feet of peat moss per plant. If you soil is loam or clayey loam, then 58 pounds of elemental sulfur per 1000 square feet will be needed. Incorporate no less than 2 cubic feet of sphagnum peat per plant.
3. Spacing is not super critical on the scale you are working with. Depending on the equipment you have available, you can use a spacing of either 4'x8' (in rows x between rows) or 3'x8'.
4. I suggest getting at least 1-year old transplants, and at least two different cultivars for superior production. While not necessary for production, this cross-pollination among the different cultivars will result in better production and larger berries. Bees are necessary for this to take place. If you have a friend that keeps hives, you might offer your patch of berries for that purpose.
5. The cultivars I would suggest come from work done at the University of Minnesota. Look for Northblue, Northsky, and Northcountry cultivars.
6. Fertilize with ammonium sulfate to help keep the pH low. Provide winter protection and irrigation; as the plants need frequent, light irrigation since the roots are thin and fibrous. Be able to provide at least 1 inch of water per week during the growing season.
7. Two important final points. Blueberries need good drainage and winter protection. If you have heavy clay soil, consider excavating it and replacing it with sand or sandy loam. Straw mulch going into winter is also a necessity.

Q: I was researching some websites to find out more about my Christmas cactus plant, and everything is still confusing. All I want to know is this: how often should I water it and can I plant it in regular soil? Also, how much water should I give it? I know it depends on the size of the pot; I have a medium pot. (E-mail reference)

A: There are two periods of critical watering; during the active growing period, and during the rest period. Through the end of January, water normally- that is completely wetting the growing medium, never allowing it to completely dry. Then, through February and March, get the plant into a cooler location and water infrequently and moderately -- enough to get the medium wetted, but allow the top 1 to 2 inches of the medium to dry before rewatering. As spring approaches in April (actually the noticeably longer days), increase the watering frequency as before, keeping the potting mixture continuously moist, but not standing in water. As for the soil, because of their high requirements for water most of the time, the Christmas cactus should never become waterlogged, hence the need for a coarse media that is peat-based, with the addition of coarse sand or perlite in a 3:1 ratio. For every part of the "normal" potting soil, add three parts of the coarse material. Ideally, these plants should be repotted every year after flowering. In spite of all of this information on "requirements" for normal growth, I know lots of folks who pay no attention to this kind of information and grow beautiful plants!

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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.

Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu