INDOOR PLANTS - Growth Factors

The Influence of Light on Indoor Plants

Light:

The ultimate source of energy for all plant growth. Radiant energy is composed of various wavelengths ranging from ultra-violet (10 mu) to electric (100,000 mu -millimicrons).

Plant and human requirements are identical. Visible (390 - 760 mu) Violet, Blue, Blue-Green, Green, Yellow, Orange, Red

Light Intensity

Measured in Foot Candles (f.c.) Bright day in July 10,000 f.c. Dull day in Dec. 250 - 500

Light Quality

Refers to wavelength composition of light. (Incandescent = richer in blue, poorer in infra-red) (Fluorescent = higher green-yellow providing better visibility to human eye.)

Light Duration

Refers to number of hours that plant is exposed to illumination Preference: Eight hour per day - bright light Tolerance: Twelve hours per day - filtered light Minimum: Sixteen hours per day - no direct light

Low light plants:

Preference 100 - 500 f.c.
Tolerance 50 - 100 f.c.
Minimum 15 - 24 f.c.

Medium light plants

Preference 1,000 - 5,000 f.c.
Tolerance 500 - 1,000 f.c.
Minimum 25 - 50 f.c.

High light plants

Preference 5,000 - 8,000 f.c.
Tolerance 100 - 2,000 f.c.
Minimum 50 - 100 f.c.

Temperature

• 65 - 75 degrees F. Plants respond to the same temperature range as humans

Moisture

• Water is over 90% of plant! Keep moist. Allow to dry. Do not overwater!

Humidity

• Best between 50-70%. Mist during summer or when room heated with forced air.

Nutrition

• Keep to a minimum! Regulate with light. High light - fertilize lightly. Low light - do not fertilize.

Atmosphere

• Keep smoke away! Smoke and air pollution clogs breathing stomata in leaves.