Light Intensities:
A. For germinating seeds and rooting cuttings:
Ten lamp watts per square foot of growing area. The light source should be 6″ to 8″ above the soil or planting media. Recent studies indicate that a high germination percentage is obtained if seeds are exposed rather than being lightly covered. Another system that may be used is to cover the seeds lightly with soil, vermiculite or perlite, then comb or scrape the surface lightly after soaking the cover medium. This allows for better light penetration and air incorporation into the seed areas.
NurtureLite fluorescent bulbs are particularly useful for germinating seeds for outdoor spring planting. When the NurtureLite seedlings are transplanted to the outdoor environment, proper steps must be taken to harden the seedlings. This is accomplished by gradually reducing the temperature and keeping the plants somewhat drier than usual until they are acclimated to outside conditions. A common procedure is to expose seedlings to the outdoors during the day and take them in for the night until they are firm enough to leave outside permanently. It may take about one and a half weeks to harden the seedlings fully. During the first few days, however, the young plants need protection from sunlight by providing some shade. An important factor to remember when hardening plants is to have air circulation, especially if they are in protected areas. This will prevent the buildup of high temperatures and thereby reduce the wilting of the young seedlings.
B. For low-energy growing plants:
Fifteen lamp watts per square foot of growing area. The light source should be 12″ to 15″ above the plant tops. Many household plants fall in this classification.
C. For high-energy growing plants:
Twenty lamp watts or more per square foot of growing area. The light source should be 12″ to 15″ above plant tops. This classification includes plants such as chrysanthemums, carnations, roses, tomatoes, beans, and most vegetable crops. When these plants are grown in enclosed areas without available sunlight, 10 to 20 percent of the total wattage should be provided by incandescent lamps or the NurtureLite bulbs. These lamps provide the far-red radiation important for normal plant development with high-energy crops.
Length of Light Periods (Photoperiod):
A. For the germination of seeds and rooting cuttings:
A light period of 16 hours produces satisfactory results. With newly germinated seedlings and rooted cuttings, prior to transplanting, a longer light period of up to 20 hours may be used with good results.
B. Short-day plants – Duration of light:
Gardenias, Poinsettias, Chrysanthemums, Christmas Begonias – 10 to 13 hours
C. Long Day Plants:
China Asters, Calceolaria, Coreopsis, Dahlias, Nasturtiums, Annuals – 14 to 18 hours
D. Day Neutral Plants (Not affected by Photoperiod):
Roses, Carnations, Begonias, African Violets, Gloxinias, Geraniums, Coleus – 12 to 18 hours
Cultural Requirements:
A. Plant ambient temperature:
For most plants, the temperature during the light periods should be approximately 70° – 75° F, and during the dark periods 60° – 65° F.
B. Plant environment humidity:
A humidity of 50% to 60% is recommended. Good ventilation is also necessary for the best growth environment.
C. Plant spacing:
Space out the plants to encourage disease-free plant growth and to promote strong roots, stems and foliage.
D. Plant watering:
Water plants when the lights are on. At this period, the temperature is rising, and there is a greater need for water from the plants.