September 27, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I changed garden areas, planted 12 hills of straight eights and have gotten three cucumbers (lots of blooms). I have tried to pollinate but evidently I'm not very good at it. We did have a real cold spell when the cucumbers were just coming up and they didn't grow very fast for a while. I am sure it is too late, but I purchased another variety of seed and have sowed them along a fence row and will try to let them vine up. I'm truly at a loss. My zucchini isn't producing well either. I've had one come to maturity. There have been three or four that have gotten mushy before growing very much. (E-mail reference)

A: If you get those late plantings to set fruit for you, let me know. That will have to be some kind of record! The mushy ends on the squash are caused by a physiological disorder known as "blossom end rot." That's right, the same thing that hits tomatoes and peppers, and it is caused by the same problem -- growth spurts from sudden rainfall or irrigation, preceded by a drought period. Simply throw them away, and don't worry about it, as it is not your fault. It happens to everybody.

Q: In the past year our birch has started to produce large amounts of seeds or catkins. Is the production of these seeds a reflection of age, or does it have to do with the sex of the tree? Our neighbor has the same type of tree except it is considerable younger and does not produce any seed. Our tree is a healthy 26 years and has started to produce lots of seed. (E-mail reference)

A: That's a sign of a mature, healthy tree -- so celebrate! In some instances, overproduction of the fruiting bodies ( the catkins) is a sign of stress, or imminent demise of the tree from borers, girdling roots, drought stress, etc. But in this case your description does not reflect that, so whatever you have been doing these past two dozen years, keep it up. You apparently are doing the right thing as far as the birch is concerned.

Q: I've started a gardening project in Los Angeles using drought-resistant plants on large plots of land that the fire department considers fire-hazards. The owners of the land let me transform the land for my Earth Garden Project. However, I've never studied xeriscaping. Is there literature that you can point me to so I can learn more about my project? (E-mail reference, Los Angeles, Cal.)

A: There is all kinds of information out there. The Denver Botanical Garden in Denver, CO is an excellent source, as well as two books, "Xeriscape Plant Guide" by Denver Water, published by Fulcrum Publishing, in Golden, CO, phone (800) 992-2908, ISBN # 1-55591-322-9, and, "Creating The Prairie Xeriscape" by Sara Williams, ISBN # 0-88880-357-5. There is more, of course, but those two references should give you just about all you would need.

Q: Is water from the sump pump safe for occasional watering of trees/bushes that we planted May, 2001? I have been doing it but heard on a gardening show it is not a good idea because of minerals or whatever the water picks up going through the soil. (Grand Forks, N.D.)

A: You use the term "occasional," which will not hurt any plant material except the most salt sensitive. However, as the sole source of water for the trees and shrubs, I think you would find yourself in trouble very quickly. Established turfgrass seems pretty tolerant to sump water if it is "occasionally" moved around. I wouldn't direct it toward any herbaceous plantings unless they are reputed to be salt tolerant.

Q: I live in Georgia and recently visited Michigan, where I noticed a maple that had purple leaves almost to black. Can you tell me the variety of maple, and will it grow below the Mason-Dixon Line? (E-mail reference, Georgia)

A: The tree you saw was likely the Crimson King maple, and unfortunately, it will not grow in the South, due to the heat intensity. Even up north, when we get extended periods of heat stress, those trees don't appear too happy. Sorry!

Q: I have several large deciduous trees in my backyard (oaks and maples mainly), and I wish to hang a couple bird feeders (suet feeders) from the trunks of a few of them. I figured I would just use nails to hang them, but I don't want to injure the trees. Is it okay to hammer just a single nail into a few trees, and if so, are there certain metals that are better to use or that I should avoid? Suspending the feeders from the branches via rope or cable is not an option in my particular case. (E-mail reference)

A: Although it is not recommended as a good treatment for the tree, a single nail being driven in for the purposes you state should not injury a healthy tree. Go for it! The birds will thank you.

Q: We recently planted a new weigela bush and after three to four weeks it seems to be dying off rather rapidly. Neither watering nor overfeeding seems to be the problem. Any suggestions? (E-mail reference)

A: The weigela needs full sun and soil with good drainage. Often dieback is a problem, so regular pruning is necessary to keep the plant in good shape. Your cultivar selection of 'Minuet' is an excellent one, and should do well for you. I would suggest contacting the nursery you purchased it from.

Q: I have a jade in my office window, which faces toward the west. It gets sun from about 11:30 or so on, all year round. There are three branches coming out of the soil. Two are about 1 inch, one is about three quarters of an inch. The smallest and one of the others have leaves that are wrinkling and shriveling, looking like your hands after they are in water too long. The leaves are thin and soft. However, the new growth on those branches seem fine. The dirt is pretty dry right now, probably about ready to be watered again. It's a 7-inch pot or so, total about 16 inches tall. Might it need to be repotted? (E-mail reference, McLean, Va.)

A: On the surface, it sounds like you are doing everything alright for the jade plant, with adequate sunlight and keeping it on the dry side. If it has been more than a year since the last repotting, then it may need it. You didn't mention your fertilization schedule. It should get a dilute fertilization every month, using something like Schulz's House Plant Fertilizer. I don't know what the story would be with those thin, wrinkled leaves - sorry!

Q: I have four gooseberry bushes which we planted two years ago. The leaves have been progressively turning a pale brown-yellow coloration starting in the latter part of June. They have produced minimal fruit. Any suggestions ? A second question pertaining to strawberries: Do you recommend any specific herbicides to minimize the weed invasion which occurs in summer ? We have been pulling and pulling weeds but tend to uproot many of the strawberry plants.

A: It sounds like rust, and at this stage there isn't anything you can do about it. Next year, spray with Bordeaux mixture after the leaves have unfolded. Strawberry weed control is a challenge. There are both grassy and broadleaf weed control products that can be used according to certain label instructions/restrictions. For broadleaf control, some formulations of 2,4-D are acceptable -- just the amine or salt form, not the ester form. Make sure you get the formulation that has strawberry on the label for broadleaf weed control. For grassy weeds, products like Poast, Fusilade, and Prisim can be used. Sinbar can be used after post-harvest renovation. Again, I repeat, be sure to read the label carefully, and know the cultivar of strawberry that you are growing, as all are not equally tolerant to these herbicides.

Q: I live in northeastern Kentucky. We planted two nice lilac bushes late in May. Over the past few weeks most of the leaves have been developing dark spots which eventually lead to a dark, dry, curled-up leaf. I assume this is a fungal infection. (E-mail reference, Kentucky)

A: Most likely it is. Not much to do now, this late in the season, except to prune out the affected branches (if they are limited in number). Clean up all leaf residue this fall. Next spring spray with lime-sulfur while still dormant, and watch carefully for disease development, taking fungicide action (mancozeb, chlorothalonil, wettable sulfur, etc.) when something looks like it is starting to happen.

Q: Do you have any information on pre-emergence herbicides for gardening and flowers? (Bottineau, N.D.)

A: Pre-emergence for flowers and vegetables mostly falls on Preen and Treflan. Simply refer to the labels for crops/plants covered, rates, and timing. Usually clean cultivation is needed, and watering in for incorporation. There are restrictions that need to be followed.

Q: My onions are quite weedy and I would like to clip them just to keep some seed from setting. It’s too late to spray and thought it may help some to clip the weeds. I have heard of stepping onions down and was wondering if I could just mow the onions off at about 6 inches, thus clipping the weeds too. I guess my only thought is, would the hollow stem collect excess moisture if it would rain, tending to rot them quicker? (Mohall, N.D.)

A: You need to allow the onions to stay as they are, until the tops bend over themselves. Your idea of clipping the weeds back before they flower is good, but you need to leave the onion tops alone, or you'll be asking for trouble.

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