February 15, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have a problem with small light-colored and black bugs on some of our indoor plants. They seem to congregate on the upper leaves and buds before they flower. We tried using alcohol, but with little effect. They seem to be like an aphid , only smaller than the ones I've seen in the alfalfa fields. (E-mail reference, Adrien, N.D.)

A: Your bugs may still be aphids, a common pest on houseplants at this time of year. They are very vulnerable to insecticidal soap, so what I suggest is to cover the top of the plant container with aluminum foil, make up a solution of the insecticidal soap in a large enough bucket, dip the entire plant in, and swirl around. For plants that are too large for this, spray the insecticidal soap directly on the plant, being sure to cover the undersides and leaf axils. Expect to make a couple of applications.

Q: Why wouldn't a garlic plant produce cloves? Is there an insect that tunnels into potatoes? People say the potato problem is not dry or soft rot. The potato is hollow. (E-mail reference, Carson, N.D.)

A: A non-clove producing garlic could mean a number of things: planted too late or planted in the spring and harvested too early, a non-adapted variety, not enough direct sunlight (they need a minimum of eight to 10 hours of direct sunlight), planted too deep (although not likely), or too much nitrogen in the soil. Concerning potatoes, yes there are almost a "ton" of insects that invade the potato tuber--wireworms, European corn borer, and cutworms to name a few. But there is a disease known as "hollow heart" that generally affects large tubers and is caused by a prolonged wet spell after dry weather. These tubers are prone to rotting in storage. The remedy for this is to keep the plants well-watered during extended dry spells.

Q: A tree advertized in Parade magazine is claimed to be a "super growing flowering shade tree that grows roof-high in just one year." The ad also says it’s hardy to 30 below zero but doesn't mention a zone. Is it something to try in North Dakota? (E-mail reference, Jamestown, N.D.)

A: No, not a candidate for North Dakota! It has too many problems and is hardy only to zone 6.

Q: We have a paper shredder and have been doing a lot of our old magazines, among other things, and I was wondering if we can add the shreds to the compost or use it for mulch. Is the color ink a problem? We are organic gardeners. (E-mail reference, Carrington, N.D.)

A: As far as I know, the color ink is not a problem, although there may be some publications that are not adhering to the non-lead base in their printing. If in doubt, don't use it. Newsprint is o.k. If it is just a few magazine publishers, you might contact them and find out if their production process uses lead or not.

Q: I have a question about my evergreen and I wonder if you would be kind enough to help me save its life. It is about 3 feet tall and I have it potted on my balcony in New Jersey. We have had a cold winter with lots of snow so I am bit concerned that the intense dryness and brown color are a result of the roots freezing. Can you recommend something I might do to save my little tree? Or is there a point in which the tree is too dry and too brown to come back? The branches are extremely brittle and snap off when you move them around, but there is still a bit of green left. (E-mail reference, Hoboken, N.J.)

A: I am afraid it’s time to give up on your tree. Root systems are not as cold tolerant as the top, and since you have had it in the container, the roots have been exposed to the ambient air temperature, which in most cases is lethal. At this stage, there is nothing that can be done to save your tree. I suggest getting another one this spring to enjoy, then before winter dig a hole in the ground and plunge the plant -- pot and all -- into the soil and cover the roots completely. Spray the foliage with an anti-desiccant prior to freeze-up and again during a late winter thaw. If putting the plant in the ground is out of the question, then I'd suggest wrapping the container in a plastic bag that is filled with straw or leaves, again spraying it with the anti-desiccant.

Q: While at the Minnesota Zoo last summer I picked up what appears to be an acorn from the trees growing at the zoo. I would like to plant it here in South Dakota. Do I crack the shell and plant only the seed inside? How deep? Does it require a lot of water? Will it grow in South Dakota? (E-mail reference, S.D.)

A: There are some two or three dozen oak species that could be growing in the Minnesota Zoo. If the oak seed is still viable, I suggest getting some unmilled sphagnum moss, soaking it completely, then wringing it out and wrapping it around the seed (acorn). Place that in the vegetable crisper in your refrigerator, and when spring finally arrives in April, check it to see if a root has begun to emerge. If so, plant it carefully, about 3 inches deep where you want the tree to be when it matures -- so give it a lot of space! If nothing has emerged by this spring, then throw it away, as it likely not a viable (living) seed.

Q: I just bought a tree. The tag says it is a "Box Orange." It has thorns and the leaves are kind of narrow and shiny. I can’t find any information for a box orange. Also, I bought a Juniper a couple of days ago and took out the moss and rocks that came with it. The soil looked soaked and was very compact, but everything besides that looked good. Then the next day all of the soil was covered with fungus. It is white, fuzzy, and smashes down to the slightest touch. do you know what it could be from? (E-mail reference)

A: I assume since you are referring to a tree known as Osage orange (Maclura pomifera) that you live somewhere south of North Dakota. It would be nice to know where you are writing from -- just the city and state. This is a tree that is related to the mulberry and is generally used in windbreaks to control wind erosion on farmlands in the Great Plains area -- Nebraska, South Dakota, Kansas, etc. It is also a good traffic stopper with those long, sharp thorns. Not too many folks will attempt to run through one of those plants more than once! The female plants produce a large, rindy fruit that we used to practice softball with. Hopefully you got the male tree, about the only saving grace this species could have from an aesthetic view. If you want some tough wood, there are few that come any tougher. It is a good one for making decks or patios as it has a natural decay resistance in it. The fluffy white mold you are seeing on the soil around the roots of your juniper plant is most likely a saprophytic mold, working on digesting the organic matter in the soil around the roots, which causes no harm to the plant. When planting, simply wash it off the roots and plant appropriately. The juniper should be fine.

Q: I have a purple calla lily and was wondering what is the best way to care for it. The tag on it said to give it plenty of sunlight or else the flower will turn white, which some of them have and then turned back to purple. My plant is already really tall. When is a good time or sign to repot the plant? Or will they grow back if I cut some of the flowers off? And are they a good flower that will last long in a vase? (E-mail reference)

A: You most likely have one of the hybrid calla lilies - Zantedeschia rehmannii mixed with something else. The flower color is really immaterial and is not an indication of improper care.

As yours continues to flower, keep the soil continuously moist. When the flower finally withers, allow the foliage to die down naturally, keeping it completely dry for about six to eight weeks. This pretty much follows the natural cycle where the plant is native. When regrowing, gradually increase the watering to the point to when, in full leaf, the pot can sit in a saucer of water. Fertilize it every two weeks. Give it as much bright light as is reasonable.Repotting and propagation can be done during the dormant period, which is generally the early summer. Lilies in general make good cut flowers, and although I have no experience with the calla types, I see no reason why they shouldn't be good keepers as well.

Q: I was hoping for some sound advice on the care of my silver maple. I'm not sure of the age, but the circumference of the trunk is at least 12 feet. My question is concerning a hole in the trunk of the tree. It appears a large branch was cut from the tree about 3 feet from the ground and through time has hollowed out. The hole is approximately a foot across and about 18 inches deep. Whenever it rains the water collects in the hole and stagnates. I try to empty it and have noticed the inside wood is quite spongy to a depth of a quarter to half an inch in most places. I have no idea how long it has taken this hole to develop. I've only had this house for three years but it is evident that the trees have been neglected. I was wondering if I should drill a hole up into the inside of the hole from the base of the trunk to let the collected water drain, or will that do more damage? The other option I have considered is covering or sealing the hole to prevent the water from entering but then thought that some may enter anyway and lead to more rot. What would you suggest? (E-Mail reference)

A: My advice is to get a tree surgeon or an arborist to determine the extent of internal decay. Properly cared for, this tree could be an asset to your property; ignored or neglected (as you indicate it has been) it can be a liability -- and a deadly one at that, depending on location.

Arboriculture and tree surgery are not trivial pursuits. Qualified arborists and tree surgeons spend years learning about their profession in a combination of higher education and field experience. The arborist could use a borer to determine the soundness of your trees, perform proper cavity repair, pruning etc. Your situation, unfortunately, is an example of what an improper pruning cut carried out years ago can result in.

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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