April 19, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have had several jade plants for approximately 10 years. Over the years they have been both in my home and in my mother's school classroom. They have grown beautifully! Over the last six to eight months, however, something has drastically changed. Initially, late last summer, the problem was all on the leaves. They appeared to have a whitish coating. I visited a local florist who recommended that I put all the plants outside and let them get fresh air. They were outside for probably two months and during that time the area that had the whitish coating tuned brown. Then it got colder and I brought them inside. Over this winter I have sadly watched the leaves fall off my previously lush healthy jade plants and they are now skeletons of what they used to be. Further, there appears to be a mold growing in the soil, which I can only equate to looking like cookie crumbs. And, the stalks seem kind of rubbery. I once again contacted a local florist who suggested that I repot them with a cactus soil, use systemic houseplant insect control and only water them every two weeks. I did, around 6 weeks ago, and crossed my fingers. As you can probably guess, the problems still exist. The leaves (which are thin and spotted with brown) are all over the floor and the soil again has the mold, fungus, or whatever it is. (E-mail reference, Chicago, Ill.)

A: The whitish coating was probably powdery mildew. The other problem could be scale causing the plant to defoliate. They usually take up residence on the underside of the leaves feeding along the veins. Many people describe them as small "bumps" on the foliage. What you are describing at the end sounds like a combination of a saprophytic mold in the soil and a parasitic fungus known as grey mold. At this stage of the game, I suggest attempting to propagate from either leaf or stem cuttings wherever the plant appears healthiest. Once they get to the stage you describe, it is very difficult if not impossible to get them back to their old form again. If you would send me your complete address, I would be happy to send you some propagation information and information on the care of jade plants. Nothing against your florist friend, but I don't think you were given complete information on the care of this plant.

Q: Do you have any information regarding salsify? I would like to know because I have an old cookbook that originally belonged to my grandmother. The book is a collection from a town in South Dakota. The recipe says to peel the salsify and cut it for use in a soup. Is that salsify vegetable the same root that comes from what I know as a weed known as salsify? I understand that the weed's root when boiled tastes like oysters. (E-mail reference, Napoleon, N.D.)

A: Salsify is a root crop known as "vegetable oyster." It should grow well in North Dakota because of its very hardy nature. In fact, my references say that it can be left in the ground through the winter. The seeds should be readily available in most in-store seed racks. They need to be directly sown in deep, stoneless soil that is free of manure. They are carefully dug in October before freeze-up, or again in April after the soil thaws. For storage, treat them the same way you would carrots. Apparently the success comes from peeling them after boiling, not before. Clean them thoroughly under running tap water, cut them into sections about 2 inches long, and boil for about 25 minutes in a lemon juice flavored water. Drain and squeeze off skins, dress with some melted butter and chopped parsley. Varieties to look for are Mammoth-Sandwich Island or Giant.

Q: I have been trying to find information on Chlorophytum and can't find much. I was hoping you could tell me if it is a native or domesticated plant and what country or region it originated from. (E-mail reference)

A: This is a houseplant that has been around for more than 200 years, originating from the country of South Africa, which to some is nearly a horticultural paradise. It "prefers" moist soil conditions, but don't believe it! I've had one growing in my house for over a decade now, and it gets watered about twice a month, if we think about it (which reminds me...). It is an extremely durable plant, tolerating low light conditions better than most through the winter months, and is a propagator's dream, producing all the off-shoots that make new plants.

Q: I am looking for some information on seeding a lawn. I am interested in a low maintenance, tough (can handle drought, being driven over, played on, etc) grass. Can you recommend any varieties that would meet these requirements? (E-mail reference, LaMoure, N.D.)

A: There are several. Park, SD Common and Kenblue are some of the Kentucky bluegrass cultivars that can be used. I would suggest the bluegrass with about 50 percent perennial ryegrass. Goalie and Gettysburg are good examples. A mix like this would be a "typical" athletic field mix. If looks are not a concern, then mix in some sheep fescue. It is cold and drought tolerant. Covar and MX-86 are example cultivars. Or, use a tall fescue cultivar like Bonanza, Arid, Rebel II or Rebel Jr.

Q: My spruce trees’ (about 2 feet high) needles are turning brown. The needles fall off when I run my hand along them. They were watered well last fall and had some snow cover this winter, but I've noticed more and more are turning brown. Here in Dickinson we have been getting some 40-50 degree days with about 20 degree nights. I dug up some soil around them and it appears to have plenty of moisture. Thanks. (E-mail reference, Dickinson, N.D.)

A: My best advice is to wait and see what happens when spring arrives in full bloom. Often the last season's growth and the current season's growth (which are still in the bud stage) will recover and the tree will green up decently. If it doesn't, then classify it as finished. I'd suggest giving it until mid May, or when the candles (new growth) start to grow on the pines. You should begin seeing similar action on your spruce. The damage could have been done months ago with the symptoms showing up just now. In the fall, recommendations are for vulnerable evergreens to be sprayed with an anti-desiccant prior to freeze-up.

Q: You have mentioned using insecticide soap to wipe leaves. Where do I find it, and what is its name? I thought the problem with my house plant (can’t think of the name!) is that the leaves nearly fell off when we were on holiday in November because Granny forgot to water, but the new leaves curl and turn brown. I checked the branches and found empty brown shells about half the size of a dehydrated lady bug. I sprayed and last week made up a systemic bug killer. I think it has helped, but the smell in the house is awful. I won't do that again! I am sorry about the name. I just can't get my brain to spit it out. It is the tropical plant you see used in Hawaii in the women's hair. Mine is not in bush form but like a rose tree.

A: Probably a hibiscus plant. I would stay away from systemics if you have to be in the same room with the plant for any length of time. Anything that smells that bad cannot be good for you.

Insecticidal soap is widely available, as "insecticidal soap." It is harmless to us but causes desiccation to the insects that it is sprayed up. They in essence dry up. The "bug" sounds like aphids. Something must have come along and sucked the living juice out of them. If my guess is correct about it being a hibiscus, leaf drop and slow-down in growth is normal leading into a "dry" dormancy. Allow it to happen, prune it back heavily after a few weeks of rest, water and fertilize, give it plenty of light, and enjoy! Summer it outdoors if you can.

Q: I have an apricot tree that grew from a seedling from the parent tree. It’s 15 years old, and each year it blossoms but the apricots fall out after a week or two of development. Some leaves on the branches are wilted and I also see some sap coming from some of the branches. Is there a fungal disease or bug infestation? (E-mail reference, Cal.)

A: It sounds like you have a couple of problems. Premature fruit drop is the result of embryo abortion from incomplete or non-fertilization of the flowers, or an insect problem. Apricots typically need two different cultivars for pollination success. If you have just one tree, or if the trees on your property are of the same variety or cultivar, that would be why you are experiencing fruit failure. Another reason would be some type of midge or insect laying eggs on the developing fruit embryos and the resulting larvae that feed on the fruit causing it to drop. My vote goes with the former reason. Wilted leaves and sap oozing from the branches indicate a borer problem to me. Once they get started, they are difficult to control. You may want to cut off those branches that are wilting and oozing below the spot where the sap is visible. Contact your local county extension agent or a competent garden center to check what is legal for borer control on your apricot. Generally, once trees become infested with borers, it is time to deliver last rites to them.

Q: I was wondering if the pyramidal arborvitae will grow well in southeast Utah. I live at an elevation of 6,200 feet and the natural flora here consists of artemesia, pinon pine, spruce and juniper. (E-mail reference, Utah)

A: The pyramidal arborvitae may grow in your part of the country, but here are the caveats:

Deer relish arborvitae, so make sure you do something to protect them if deer are common in your area, which I suspect they may be. Winter burn can be a problem if planted in an exposed location. For foundation plantings, an east or northern exposure--if not entirely shaded--will do well. Select cultivars that have proven to be more resistant to winter burn and are dependably hardy in zone 3, such as Brandon, Gold Cargo, Hetz Midget, Techny and Wareana.

Q: Why can't I grow radishes? Our garden is rototilled every spring so it can't be that the soil is too heavy. Every year the tops grow well, but only two or three plants produce radish roots. I have talked with other gardeners in the area who also have the same experience. (E-mail reference, Moorhead, Minn.)

A: The most common cause for no radish root production is too high a nitrogen content in the soil. You may be using a fertilizer that is too high in nitrogen, resulting in great top growth but essentially nothing in the roots. If they are being grown in too much shade, root development will be either poor or non-existent. Other causes could be wireworm or root maggot infestation. I suggest trying to grow your radishes in another location. Make sure there is at least six hours of direct sunlight reaching the site.

Q: My husband recently brought his spider plant home from work, and it was growing little brown bubbles along the stem. I don't know if we should remove these bubbles (they fall off easily and are greyish underneath) or leave them alone. They aren't moving, so I don't think they're bugs. Can you tell me what to do? (E-mail reference, Kent, Ohio)

A: They could very well be armored scale. They don't move once they have developed the protective shell over themselves. You might take a sample to your local county extension office for confirmation and advice. If it is scale, they are generally difficult to control and require a couple applications of systemic insecticide. I hope I am wrong, as these are beautifully durable plants, normally tolerating heaps of benign neglect.

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