NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

December 30, 1999

Hortiscope

Ron Smith, Extension Horticulturist
North Dakota State University

Note to readers: With the new year and century beginning, I want to get everyone off to a good start when sending inquiries or samples to me. What follows are my communication preferences (in order of preference) and the guidelines I'd like you to use:

• E-mail. I need an address, city and state, before I will answer any email questions.
• Surface mail. Make sure you have your name and return address somewhere on the envelope or in the letter. If you are going to send samples, pack them DRY, please. I am not a plant pathologist, so plants going through the process of rot don't turn me on! And please be as descriptive as possible. Many times I can get the answer right--not from the sample--but from your description if it is good enough.
• Telephone. My least favorite means of communication, as it frustrates both of us. I am usually out doing field work, attending meetings or teaching class. If I am in my office, I am usually in preparation of one of those activities.

I attempt to answer all inquiries as soon as possible, taking them in the order they arrive. Some inquiries can be answered in a matter of minutes. Others will take consultation with other professionals on the campus, and may take hours or days. When it is going to involve the latter, I will let you know so that you will not think your inquiry has fallen through the cracks.

If you can follow these basic guidelines, it should allow me to answer your questions more quickly and serve your interests better. Thank you!

Q. I received a beautiful poinsettia early on during the holidays, and it still looks great! What do I now do with it? I just cannot bring myself to throw it away! (Grand Forks, N.D.)

A. Poinsettias have improved dramatically over the last several years. It used to be that if you got one around Thanksgiving as a house gift, you considered yourself lucky if they made it `till Christmas! Nowadays they can last up to Valentine's Day or beyond.

Simply keep it watered and in a location where the lighting is good. As the red leaves begin to whither and fall off, or when the plant finally gets too unkempt to be worth looking at, you can either dump it then, or move it to a less visible spot, keeping it barely watered.

When spring arrives and the frost threat has past, you can set it outside to grow as a small shrub to be used as a means of propagation for some new plants or to simply get the same one to re-flower for you next Christmas. If you are interested in the latter, then simply cut the plant back to size in mid-August, and bring it inside well before any frost arrives. Begin subjecting the plant to long nights at the end of September by covering it with some light-proof material by 6 p.m. and keeping any stray light from the plant until 7 a.m. Around mid-November or so, the top leaves should start turning color, and once that has started, you can stop covering it at night.

Q. I have tried in vain to grow houseplants, but every one eventually croaks! I have read several "how to....." houseplant books, but I still fail. Should I give up and simply harbor plastic plants or go for none at all? (Williston, N.D.)

A. Since your question is so general in nature, my answer will be likewise. I'm not sure anything I can say will give you success, but perhaps a review of the basics may highlight something you are missing.

Houseplants can be broadly divided into two categories: flowering and foliage. The flowering types like African violets will need a higher light intensity than the typical foliage plant, like the split-leaf philodendron. During the winter months, the biggest enemies of all interior plants are the dry air and drafts--both cold and hot. Some can get through these conditions with essentially no problem, like the dumbcane, while others, like spider plants, may show some tip burn on the foliage, and still others like the Norfolk Island pines, may defoliate altogether! As a sweeping generalization, it is a good idea to mist most houseplants during the months of November through March with distilled water to help overcome the low humidity. The exception to this would be any houseplants that have fuzzy leaves, like African violets.

Fertilizing and watering of houseplants can be again broadly divided. Foliage houseplants need less fertilizer than faster growing flowering plants. When in doubt, don't fertilize! More houseplants are killed from over-fertilization than under-fertilization. The same holds true for watering; when in doubt, hold off on the water, again for the same reason.

Often the foliage collects dust, making for an unattractive plant. The dust also interferes with light absorption, so the cleaner the leaves, the more efficiently the plant can photosynthesize. The best procedure is to simply take a clean rag, spray the leaves with distilled water, and wipe the upper and lower surface clean. If a commercial leaf shine is going to be used, then do only the upper surface. This material tends to clog the stomatal openings of plants. If both sides are covered, the leaves will turn yellow and drop off. With the fuzzy leaf plants the only way to get the dust off is to blow or gently vacuum it off.

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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: Dean Hulse (701) 231-6136