There is much excitement among African violet fans in Atlanta.
No, it is not the discovery of a yellow-flowered variety or a brand-new type. Rather, it’s news of a comparatively new method of culture that produces African violet plants of unusual character which far outshine similar plants grown conventionally.
This system of culture consists of growing the violets under fluorescent lights, and believe it or not, they can be grown to perfection right in one’s basement, where the plants receive no daylight whatsoever!
Best Conditions When Grown Under Lights
Mr. and Mrs. Phillip Genntisson of Atlanta, Georgia, are credited with having worked to determine the best conditions under which African violets can be grown to perfection under lights.
They experimented with light tubes of different intensities, different heights of the fixtures above the plants, watering and feeding requirements, and even different soil mixtures.
For instance, they learned that soil mixtures had to be different for such conditions than those used for ordinary house culture. So, by trial and error, the Genntissons finally developed a system that produces some of the most beautiful plants I have ever seen.
Their plants are grown in the basement, where they get practically no light from the outside, and the cutting bed is getting none at all. Therefore, their plants depend entirely upon fluorescent tubes for their light source.
The couple started with just one double lamp unit with a reflector and now have seven units on double-decked stands and over the propagating bed of sand.
Fluorescent Lighting Method
After seeing the quality of growth of the Genntissons’ plants under lights, I have converted to the fluorescent lighting method of plant culture.
During the time I have seen their experiments, here are some things I have noticed:
- Very profuse flowering-some plants have 250 or more flowers open at once.
- Fluorescent light seems to produce larger leaf blades and shorter petioles. This is a condition that many prefer, for extremely long petioles take up a great deal of lateral space, especially in the Ionantha type.
- The leaves lie flatter than they do under other types of lighting. This tends to produce interesting foliar patterns, as the leaves spread out in perfect geometric patterns on a horizontal plane. The plants are beautiful in leaf alone.
- The flowers seem to be produced in dense clusters well above the leaves, thus eliminating the difficulty sometimes experienced when leaves often cover up flower clusters and hide them. The result is a rosette effect.
The overall perfection of growth of African violets under fluorescent lights is so outstanding that these plants were not allowed to be shown in competition with plants grown under other conditions at the annual meeting of the African Violet Society of America, Inc. Now, special classes are being written just for plants grown under artificial light.
Propagating Bed
The Genntissons’ propagating bed is of special interest. It’s made in a built-in wall on one side of the basement where there are no windows at all.
Sharp sand is used as a rooting medium, and the leaves and rooted plants here were the freshest I have ever seen.
A small electric fan keeps the air in circulation, while a thermostatically controlled gas heater maintains the proper temperature in the basement during winter.
Under lights, African violet cuttings rooted and developed clusters of leaves in three weeks, when they were rooted in sand in glass dishes somewhat like deep glass dinner plates. These plants bloomed six weeks after the cuttings were placed in the sand.
That is a record in my book. Cuttings started in the regular sand bed. However, they took much longer to strike roots and develop into a blooming stage.
Mrs. Genntisson’s theory is that this quick rooting must be due to some light reflecting the root systems through the glass container.
Growing African Violets In Glass Pots
Another observation has been that plants growing in glass pots sport much more than those growing in regular pots.
The sport was in the form of varying degrees of yellow mottling of the leaves, producing a variegated foliage effect.
While on the subject of the growth of plants under fluorescent lights, I noticed that the Genntissons had excellent results in raising and flowering gloxinias and tuberous-rooted begonias under the same lighting arrangement that they had set up for the violets.
Now, for the mechanical features of the lighting equipment. The plants were exposed to light for 12 to 14 hours daily.
In winter, they are given 16 hours a day. The seven double lamp units in reflectors are all connected to an automatic time switch so that the Genntissons do not have to turn the lights on and off.
When I observed it, the switch was set to go on at 8:00 a.m. and shut off at 11:00 p.m. When the couple went to Florida on vacation, they only had someone see that the plants were watered as needed—the time switch took care of the lighting arrangements.
Time Switch
The time switch is the ordinary, inexpensive type used on farms for controlling lights in chicken houses. This type is one-half to one-third cheaper than the regular time switch-on lighting hook-ups in stores. It is a Montgomery – Ward switch. Sears Roebuck has one like it, too.
Reflectors carrying two 20-watt lamps were first used in the lighting set-up but were discarded for lack of proper illumination.
Now, the Genntissons use two 40-watt tubes, 48” inches long, in each reflector, providing 80 watts on each stage.
Reflector
The reflector is a Westinghouse unit, style No. 1776037, Type 2HP 40. These are closed at the ends. Some growers prefer open-end reflectors to allow a longer lateral light diffusion. This is style No. 1376045, Type 2 HPR 40. Both have porcelain reflector surfaces.
One would immediately think of the cost of operating electrical equipment, so I asked the question early in my interview.
The answer was rather surprising—10 cents every 12 hours of continuous operation for all seven units. This was further confirmed by Mrs. G. E. Rhodes, also of Atlanta, who has recently installed similar fluorescent units in her greenhouse.
44659 by Charles J. Hudson, Jr.