Lighting Conditions

Light & Skylights

All plants require different amounts of light to photosynthesize (manufacture food) and grow. Quantity and quality of light available indoors is significantly less than light in nature. Window size, distance from the window (to the side or under), the presence of curtains or shades, partial obstructions (awnings, overhangs, trees, etc.) influence the amount of light the area receives. Our light code is a guide for your plants, and should be adjusted to seasonal variations and individual locations. In WNY, it is unlikely that any plant indoors will get too much light, so plants in the lower light categories will grow in many higher light areas (although they may need more additional care).

  • Low light: under a bright fluorescent fixture, at least 50-100 footcandles measured at desk height
  • Medium light: near windows (2-4 feet back or set to side of South, West, East window) 100-250 footcandles
  • High light: directly in front of a window (without blinds, shading or overhangs) over 250 footcandles. Other High light plants:
  • Giant Plants: Trees and palms up to 30’L

These light intensity categories are based upon duration of 10-12 hours per day minimum of 5 days per week. Lower duration of light requires higher intensity for plants to live.

Skylights provide natural light which is ideal to sustain large foliage plantings. Plan for angle and placement of windows and skylights to provide as much direct sunlight as possible. Many large foliage plants require up to 6 hours of direct, unfiltered sunlight to sustain growth. Light shines downward, but only penetrates at an angle of 30-45 degrees. This means that a skylight in the middle of an atrium may not shine onto planters at the edge of the room. The angle of light changes drastically on a seasonal basis (as shown in photo to left).

The following changes the amount of light that reaches the plants:

  • Height of roof and distance to travel to leaves (light at 20′ above floor is 2x light at 10′)
  • Smaller width of skylight (if narrow, light may only shine in from 11am to 1pm)
  • Glazing, tinting, and use of opaque materials instead of clear glass (can reduce up to 90% of sunlight)
  • Direction & angle of skylights – light sweeps from east to west, shining below on the opposite side of the skylight; north side has no direct light, south has bright ambient light.

FULL SUN – Unobstructed south, southeast, or southwest window that receives direct sunlight for at least half the day. No curtains or shades. Plant should be directly in window (if plant is greater than 2 feet back, this is not Full Sun even if sunbeams are striking the plant) (1200-5000 footcandles). Plants that like this:

Floor plants:  Most Palms, Orange Trees
Hanging Plants: asparagus fern, begonias, variegated english ivy
Table plants: Orchids, all cacti, jerusalem cherry

PARTIAL SUN – Unobstructed east or west window that receives sunlight for 2-4 hours. Plant should be only 2 feet directly back from window (600-2000 footcandles).

Floor plants: Rubber Trees, Ficus Benjamina (weeping Fig), Areca Palms, Crotons, Aralias, Norfolk Island Pines
Hanging Plants: Spider plants, swedish ivy, Ferns
Table plants: Succulents

VERY BRIGHT LIGHT – Directly in an unobstructed north window, full sun window with sheers, 2-4 feet back from S, E, W window, or fluorescent gardening light (300-800 fc).

Floor plants: Schefflera (umbrella tree), Philodendron, Ponytail Palm, Dracenenas (Corn Plants)
Hanging Plants: Boston Fern, Lipstick vine, Grape Ivy, Piggybacks, Gesneriads
Table plants: African Violets, Babies Tears, Bromeliads, Ferns

MEDIUM LIGHT – North window with sheers, or to side of sunny window, or 3-6 feet back of sunny window (150-500 footcandles).

Floor plants: Pleomele, Spathiphyllum (peace lily), Rhapis (Lady Palm), Arboricola (mini umbrella tree), Dracenena Marginata (Dragon Tree – green and white variety not “rainbow” this is Partial Sun)
Hanging Plants: English Ivy 
Table plants: Mini Spathiphyllum (peace lily)

LOW LIGHT – Directly below interior office fixture, or more than 6 feet back from window, or more than 2 feet to side of window. Plant species must be carefully chosen for this light level (75-150 footcandles).

Floor plants: Aglaonema (Chinese Evergreen), Aspidistra (Cast Iron Plant), 
several Dracenenas: Janet Craig, Warneckei, and Massangeana (Corn Plant), Sanserveria (snake plant or mother-in-law’s tongue), Neanthebella Palm (Parlor Palm)
Hanging Plants: Pothos
Table plants: Aglaonema (Chinese Evergreen), Sanserveria (snake plant or mother-in-law’s tongue), Pothos

****Below 75 footcandles, even low-light plants have trouble thriving.