The Light Needed for African Violets in the Winter

About African Violets

• African violets were discovered in eastern Africa in 1892 and introduced into cultivation several years later. Two species, Saintpaulia ionantha and S. confusa, are the parents of the modern hybrids. African violets prefer a warm, humid, moist environment with a medium light intensity similar to their native habitat, the forest of the Usambara Mountains. Though the humidity in the mountains is 70 to 80 percent, 50 to 60 percent humidity is adequate in the home. Temperatures should be 70 to 80 degrees during the day and no lower than 60 degrees at night. Given these conditions, African violets can flower almost year-round.

Light Requirements of African Violets

• Some varieties of African violets need more light than others, but, in general, 900 to 1,100 foot candles of light is best. This level is bright, indirect sunlight, just enough to throw a faint shadow. If you place them in a western or southern window, use a light curtain to filter the light during the summer. Winter light levels should be the same as summer, but, since the sunlight reaching the earth is less intense and the hours of daylight are reduced, you should either move your plants to a sunnier window or supplement the sunlight with artificial light. Place plants 18 to 20 inches beneath grow lights for no more than 16 hours a day. An eight-hour period of darkness is essential for flowering.

Symptoms Of Too Much Light

• African violets exposed to direct sunlight usually develop smaller leaves than turn down at the edges. The leaves may be be brittle and bleached. There may also be brown spots on the flowers and leaves, indicating sunburn. Stunted plants, however, can also be caused by a temperature drop below 60 degrees.

Symptoms Of Too Little Light

• In low light, leaves will grow upward instead of lying flat and the stems will elongate as they try to reach the sun. The plant can stop flowering and the leaves may turn yellow. Moving the plant to a bright but not sunny window should correct the problem in a few days.