January 10, 2002

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I would like to know if miniature carrots are grown from seed, or are they cut from big carrots? If they are grown from seed, how long does it take from the time they are seeded until they can be harvested? (Robinson, N.D.)

A: There are both, carrots that are cut to miniature size and true miniature carrots. They will take between 50 and 70 days before harvest, depending on variety, site location, and cultural practices.

Q: I have a beautiful large Christmas cactus. The problem is the branches are quite big, rotten, and breaking off. I would like to know why this is happening. I have the plant in a self watering pot. I water it weekly. (Jamestown, N.D.)

A: You are most likely having root rot problems, along with some type of leaf decay. If you can find some healthy leaf tissue, snip it off and root in a sand/peat mixture after allowing the cutting to dry for two to three hours. That is probably your best bet for perpetuating this plant.

Q: Are you familiar with the antidessicant Wilt Pruf (active ingredient 25% pineoleene)? The label says not to use on juniper, cedar or arborvitae. Why? These are the species most in jeopardy. They say to apply in March. I think that's too late for the U.S. Can you enlighten? (Devils Lake, N.D.)

A: Yes, I know the material well. The reason they suggest not using it until March is that is the time the plants are most sensitive to possible foliar desiccation, when the soil is frozen or nearly so and the plant cannot uptake adequate water for the transpiring foliage in the bright late winter/early spring sunlight. The common practice is to apply it in the fall before freeze-up, which is all right, but then 90 to 120 days later the material bas broken down, washed off, or simply degraded, and isn't performing its intended function. The recommendation to not use it on the species they list is because research has shown that the material has a phyto-toxic effect on those conifers under certain conditions. Foliar burning (winter burn) was reduced when the application was made in March when the air temperatures were warmer, but the soil was still frozen or too cold to transport sufficient moisture to the foliage.

Q: In September 2001 we found an acorn for a bur oak and planted it in a pot here in our office. It is a sapling with seven leaves and 5 inches tall. I looked on the web and through my research discovered that we never should have started growing it in a pot in our office. Or could we consider this a bonsai? Now we are desperate to save it. The leaves are turning brown at the tips. We have kept it moist since planting; never letting it dry out. Is it too much water? Not enough sunlight? (E-mail reference)

A: You did not state where you live, but yes, the acorn should have been planted outdoors rather than as a "houseplant" where it is doomed. I am afraid that there is not much that can be done to save the tree at this point; bur oaks do not make good bonsai specimens, and it is likely getting too much water or is in a poorly drained container. The poor plant is now confused! You have given it a false environment, making it react to what it interprets as "spring" in your office. The leafing out and deciduous nature of the plant is controlled by daylength, so again, the plant doesn't know how to read this human controlled environment and is slowly succumbing. I'd suggest enjoying what days it has left, attempting to adjust the light and watering situation as best you can, and when it finally dies, know that you have learned a good lesson in plant physiology.

Q: I was in a hotel and kept admiring an unusual fern. As I was leaving I took one last look and realized that it had small fern plants growing up and down the fronds. I snitched a couple (as any responsible gardener would do) and am now rooting them. I wonder if you know what kind of fern it could be. Are "piggy back" ferns common? I have never seen one. (E-mail reference)

A: I really don't know if they are common or not. According to one of my references, they are not. I suspect what you may have "snitched" was the Asplenium bulbiferum, or the hens and chickens fern, which produces bulblets or plantlets on the upper leaf surfaces.

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