Lighting House Plants

Green plants live off light the way animals live off food: They absorb it and convert its energy into the sugars and starches they need to grow and survive. Without adequate light, no plant can thrive.

Fortunately, house plants tell us when they are not getting enough light. Their growth will be pale, and they will stretch toward the nearest light source. Flowering will be weak or totally absent. It becomes impossible to water them adequately: Without sufficient light, they can’t use the water we supply, and eventually rot sets in.

succulent house plants
Southern exposures get full sun from late morning to mid-afternoon.

The light needs of different house plants vary. What may seem like a dark corner to a flowering house plant may be perfectly acceptable to a foliage one. Whatever your conditions, as long as enough light to read by exists, certain house plants will thrive there.

Seasonal Differences

Light intensities vary according to season. A south window, which may be too intense for many foliage house plants in the summer, is the best location for most house plants during the winter months. During the summer, move plants back from hot south or west windows, or draw a sheer curtain between them and the glaring sun. A north window, on the other hand, may not receive enough light for flowering house plants during the winter, but almost every house plant will thrive in its cool brightness during the summer months. Never hesitate to move house plants from site to site according to season.

Improving Natural Light

If your house plants show signs of lack of light, you can increase the intensity they receive by removing any obstacles that block the path of the light: for example, curtains, blinds, and outdoor foliage. Even cleaning the windows regularly will help. Another easy way of improving light is to paint nearby walls and furniture in pale shades, so they reflect light rather than absorb it.

Artificial Light

House plants adapt perfectly well to growing under artificial light. Incandescent lamps, however, even those offered for plants, produce light of poor quality that promotes weak, unhealthy growth. They are only good choices for house plants receiving some natural light. Fluorescent lights and halogen lamps, on the other hand, produce light so close in quality to sunlight that house plants will thrive under them. For best results, use artificial light on timers set at 12- to 14-hour days and make sure the lamp is far enough from the plants so they don’t overheat.

Window by Window

Light exposure varies among the windows in your home.

  • South Window: This is the sunniest exposure, getting full sun from late morning to mid-afternoon and bright light the rest of the day. Such locations will especially suit flowering house plants and those from arid climates, like cacti and succulents. Plants can usually be placed quite a distance back from a south window and still get very good light.
  • East Window: This location is often considered the best for growing house plants. It receives full sun for a short period in the morning and bright light the rest of the day. Cooler than a west window, it allows house plants to get the bright light they need without danger of overheating. Both foliage and flowering plants thrive here.
  • West Window: Like an east window, the west window receives full sun for part of the day and bright light for the rest. Its main disadvantage is that many house plants find such a spot a bit hot for their tastes. Both foliage and flowering plants thrive here.
  • North Window: House plants in north windows receive no direct sun, but, depending on the season, can receive bright light for much of the day. Generally speaking, only foliage plants will thrive here and even then, they must be grown close to the glass.

In the next section, we'll talk about watering house plants.

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