I have seen artificial lights that would exceed daylight by 50%, with air-conditioning equipment to pull down temperatures brought about by the heat thrown off by the lights. Yet, such layouts are beyond the ability and the purse of most amateur gardeners. Growing Plants Indoors With Artificial Light In The Basement. What does fall into the realm of the possible is the growing of certain plants in a basement, entirely by artificial light such as African violets and Venus fly trap plants.
All of these are what we call “forest floor” species. They are plants which have been conditioned to survive under the trees of a forest, where light intensities are low. This group includes plants like such as African violets, carnivorous plants, all begonias, browallia, impatiens and many others. If a species will grow and flower in the shade, it can probably be grown entirely by artificial light. Fluorescent grow lights made it possible for one couple to Grow Cattleya Orchids in their “Basement Greenhouse.” This is where the third “dimension” of light comes in. Until now, the actual spectrum emitted by the source of light was not too important. When all the light needed by the plant comes from an artificial light source, the light quality is vital. For vegetative growth and flowering, the shorter blue light waves (which are close to the invisible ultra-violet spectrum) seem to be important.
So, too, are the longer, red wavelengths, close to infra-red or invisible heat waves, but these are not needed in as large amounts. Fortunately, a very close approximation of natural daylight can be had by the use lighting system where daylight fluorescent tubes and light fixtures, are suspended about 10 inches to 12 inches above the plants. The more light you can use on a given area, within reason, the better. The use of a completely-enclosed growing case and grow tents solves many of the problems involved in growing plants by artificial lights. Inside such a case or grow tent: … can be controlled so closely that graphs representing each factor show as practically straight lines. In the open basement, it is difficult to maintain humidity high enough for good growth. On the other hand, humidity can be kept at close to 100% without much difficulty in the enclosed plant case. What can be grown in such a case, or on an open bench with high humidity? One of the most satisfactory subjects is the tuberous begonia: light-sensitive plant, this species thrives on the long days that are possible under artificial light. If lights are kept on 24 hours a day, or are kept on 16 hours and off eight hours, very little difference in results. A friend in LaGrange, Illinois, has grown tuberous begonias from seed to flowering, and kept the plants flowering continuously without a break. He has eight separate enclosed cases, growing a wide range of plant materials. African violets are particularly successful and impatiens also. One of the most important uses for artificial light is in the propagation of plants; here light quality enters the picture again. Daylight white fluorescent tubes supply the blue wavelengths light end of the spectrum, while the incandescent supplies visible red wavelengths light lacking in the colder light. Normal growth of foliage and flowers is favored by the blue light end of the spectrum, while root formation is stimulated by the visible red light end. Instead of the daylight tube, the so-called soft white fluorescent tubes is best for rooting cuttings. These need more of the red light end of the spectrum, which can be supplied by the use of this type of tube. Results in a closed case or grow tent are sensational. I have propagated dozens of types of cuttings, with minimum loss and practically without attention. Once the cuttings are “stuck” in the pot mix of soil or flats, the lid is closed and need not be opened, except for inspection, until the rooted cuttings are removed. A highly satisfactory use for artificial light has been in the forcing of Dutch bulbs without a sunny window. Hyacinths, tulips, and narcissi are potted as soon as received and kept in a dark location at 48 degrees until the shoots are two to three inches out of the pots. Long, cold storage treatment is unnecessary except when bulbs are to be held back for later forcing. Once the shoots are developed to a length of three inches, the pots are placed under fluorescent tubes.
Two 40-watt tubes suspended 10 inches above the pots will light an area 12″ x 48″ inches. Temperature should be kept as close to 55° degrees as possible. In forcing bulbs, I find that excellent pot plants can be grown with only fluorescent tubes. However, if the flowers are to be used for cutting, the addition of a 60-watt incandescent bulb to the two tubes seems to produce a plant lasting longer in mineral-free water. Artificial Light Used To Replace Or Supplement Direct Sunlight. Metal Halide Light is a bright light with exceptionally long life span. You’ll often find Metal Halide fixtures used for vegetative growth stage and High Pressure Sodium (HPS) fixtures for the flowering stage. High-Pressure Sodium (HPS) grow lights are High-Intensity Discharge (HID) lights. The light they produce is in the orange/red spectrum an ideal lighting for the flowering stage. Many cannabis plant growers claim high-pressure sodium lights are ideal for flowering marijuana plants.
Compact Fluorescent Plant Grow Lights (CFLs) – These energy efficient grow lights for houseplants are growing in popularity for both propagation and plant growth. While not as efficient or with as much intensity as HID lights, fluorescent deliver better color and spectrum light providing more useful light per watt to the plant.