Houseplant Care: Proper Light

Proper lighting is critical to the success of any houseplant. This article discusses some of the things to keep in mind when deciding where to put your plants.

Light is one of the most important factors in the successful raising of houseplants, yet is also one of the most misunderstood. Many novice plant-owners have a notion that because plants need light to grow, one simply needs to stick a houseplant in a south-facing window and let it be. Doing this, though, would be as disastrous as putting the plant in a dark closet and shutting the door.

Proper lighting for houseplants has two dimensions: length and intensity. Most plants require the same duration, or number of hours per day, in which light shines on them. This is anywhere from twelve to fifteen hours, although exceptions exist. If plants get less light than this per day (during the winter months, for example), growth will slow down. This is why most plants go through a resting period between fall and spring, when daylight hours are shorter and there is less time for the plant to absorb the energy it needs from light.

The trickier aspect of proper lighting is determining how strong the light needs to be. Despite the popular notion of the plant sitting in the sunny windowsill, most plants can't handle this kind of light intensity, particularly with the glass magnifying the sun's rays. Unless the plant is a cactus or other desert dweller, most plants will be scorched by such intense light.



Most plants fall into one of five categories of light requirement. The first is the aforementioned full-sunlight plants - usually cacti or other succulents that can withstand the sun blasting them all day. In order to provide this type of light for a plant that requires it, set it as close as possible (within a foot or two) to a south-facing window.

The second type of plant is one requiring a brightly lit area, with some direct sunlight. There are many plants which fall into this category; flowering plants such as impatiens and chrysanthemums often grow well in such light. If you own a plant such as this, you can place it either on an east or west-facing windowsill, or near a south-facing windowsill (but not too close - the flowers will singe!) that is partly obscured.

The third category are plants which require bright areas of the room without direct sunlight. Popular plants such as bromeliads and philodendrons flourish well in these conditions. Place the plants so that they are about six to eight feet away from an east-facing window. You can also put them in a windowsill which doesn't receive any direct sun.

Some plants, especially non-flowering plants, require less light than others. Many of these will survive and even flourish in a semi-shady area. Plants such as the Dracaena and a variety of ferns are extremely popular because of their ability to grow beautifully in less than bright conditions. These plants do require some light, though, so make sure that the room gets some sunshine, even if it doesn't extend to where the plant itself sits. Eight to ten feet away from a sun-filled window or a few feet from a sunless window should do the trick.

Finally, there are a few plants which will grow without very much light at all, although even these hardy plants need a little light to prosper. Too much light, though, and they will perish. Keep the plant well away from any window, but make sure that the room gets enough light during the day so that you don't have to turn on a light to see or read.

If your house doesn't have the windows to provide enough light for all the plants you wish to grow, it is possible to use artificial light. If you choose to do this you will need to buy either fluorescent bulbs or specially designed "grow bulbs" which provide the full-spectrum required for the plant to translate light energy into food production. You will also need a special unit to house the bulbs - this usually hangs over the growing area and has a reflecting, curved surface which deflects and angles the light onto the plants. It is still important to keep in mind the proper lighting conditions for each type of plant - if the artificial light is too strong you will see the same leaf-scorching that occurs with natural light. There are many advantages to setting up an artificial-light growing center in your home, not the least of which being the ability to keep flowering plants in bloom all year long.

Before you purchase any houseplant you should talk with the salesperson about what type of light the plant needs. Think carefully about whether or not your home has the proper windows to allow for this type of light. Most plants can adapt to less than ideal conditions; for example, plants which require bright, direct sunlight can usually adapt to a bright, indirectly sunlit spot, and vice versa. However, if your home only has one or two windows that let in very little light, it would be murder to bring home a plant that requires a lot of sun. Keep this in mind, no matter how beautiful you think the plant will look in your home.

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