December 18, 2003

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: Has anyone attempted to grow cloudberry or lingonberry in North Dakota? I am doing research on my family, which is mostly Scandinavian so I am interested in these fruits. (E-mail reference, N.D.)

A: If they are grown here, it is a well kept secret. You might contact St. Lawrence Nurseries in Potsdam, N.Y. Their e-mail is trees@sin.potsdam.ny.us  and their Web address is http://www.sin.potsdam.ny.us.  Or, you might just want to give them a call at (315) 265 6739.

All of their material is organically grown. They may have other contacts that can help you. The owner's name is Bill MacKentley. He is very knowledgeable, but give yourself time when you call because he likes to talk!

Q: I recently cut down my elm tree because of a disease. I have a fireplace and am wondering if I can burn the wood or should I wait a year or two to let any potential eggs die? (Fargo, N.D.)

A: No problem burning it but you should do it as soon as possible.

Q: My Christmas cactus is very old as it belonged to my husband's grandmother. In the past it has had lots of blooms. Last spring it had only two buds. I moved it to a new location that it seems to like. It has lots of new growth but has just started growing tiny root like buds in most of the joints. Can you tell me why it is doing this and what I should do to get it to bloom once again? (E-mail reference)

A: The buds are likely the start of aerial roots that sometimes form on tropical cacti, which is nothing to worry about. These plants need short days and cool temperatures to get them to flower. Cover the plant with something that excludes light 100 percent at twilight. Keep it covered for more than 12 hours. Eventually the buds will form. You can stop covering the plant when that happens.

Q: There are "balls" growing on my oak tree. What are they? (Galesburg, N.D.)

A: Your sample was of the oak bullet gall wasp known as Disholocaspis quercusmammor. Their damage is cosmetic but not lethal. No control is necessary or practical. Tiny insects known as gallflies or minute non stinging wasps will eventually attack all oaks. Both insects cause galls, gallnuts, or just plain oak balls.

Q: I have a hoya that I am caring for. I was told that it is a healthy plant and is approximately four or five years old. There are one or two yellow tipped leaves. Is it normal for it to have some white spots on the leaves? The spots look like sap. (Rapid City, S.D.)

A: A healthy hoya or wax plant should have dark green, uniformly colored leaves. The white spots could be scale insects and the yellow tipped leaves could be an overwatering problem.

Q: Any idea what might cause a cut spruce tree to smell like rotten eggs? I received a call from a lady saying her tree smelled foul about 24 hours after they set it up. She said they cut the bottom off and placed it in water. (Bowman, N.D.)

A: It could be that some miscreant sprayed it with a sulfur based solution to spoil someone's Christmas. Or, perhaps the tree was harvested without permission and this is the owner's revenge for having illegally taken the tree. Illegal harvesting of shapely spruce and pine is not uncommon around this time of year. Hope that isn't the case in your situation!

Q: Are white pumpkins safe to eat? We have some white ones but don’t know the variety. The flesh was a nice orange when we cut into them. (E-mail reference)

A: Should be okay to eat but don’t eat it if the flesh has a bitter taste. The variety is probably Lumina, which is a common white pumpkin.

Q: Do you have any information on princess pine? It is the evergreen like plant that greenhouses use in floral arrangements, especially this time of year. I have no idea if this common name is even correct. (Bottineau, N.D.)

A: I think you mean reindeer moss or club moss. They sometimes make wreaths out of the stuff and use it in arrangements depicting Christmas or winter scenes. That's the best I can come up with.

Q: We have a Christmas cactus that I’m guessing is about 25 years old. It has been pruned so it appears almost like a tree. It is beautiful when it flowers but recently I noticed a limp branch that fell off when I touched it. Where the branch broke the inside core is fibrous and shriveled and there is a gap where it looks like the core shrunk away from the outside bark. I am not sure if I should cut it back or just leave it as is. (E-mail reference)

A: I wish I understood the Christmas cactus better myself! If I ever get a graduate student interested enough, I'd have the student do an international search on this plant species and conduct at least two years of research on all the hybrid variations of this species that exist. I’d also have them study all the cultural nuances that could possibly come up. I wish the plant was not referred to as a cactus because it places it in the realm of a desert species for most people. It is a species that is native to the tropical forests of Central America. They grow as epiphytes (above ground) in the limb structure of mature trees where decaying organic matter has collected. It has the ability to form abscission layers between the various limbs or leaves when things begin to dry up too much either through the soil or air. I think that’s what happened to yours so it’s not a disease, just a plant's reaction to the dry conditions (you live in Vermont and have been using your central heating system, I am sure!). I suggest monitoring to be sure the condition does not progress but I don't think you have anything to worry about. Don't prune it until it begins active growth again sometime in March or April. Check the plant for mealy bugs, as they are a common infestation of this species, which could cause the limpness that you describe. If present, dab them off with a Q-Tip dipped in rubbing alcohol.

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: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu