Home Gardening

Indoor plants need proper lighting all year
Mississippi Gardens Newspaper and Web Column - December 8, 2003

When freezing weather approaches it's time to bring the houseplants in to protect them from cold damage. While outdoors on the porch or patio most tropical foliage and flowering ornamentals get the light they need or else they let you know pretty quickly that something is wrong. Typical indoor plants need proper lighting all year long. Improper lighting is a major problem houseplants are subjected to, second only to over-watering.

A friend loaned me a light meter and I was amazed at the differing amounts of light there are in my office. My eyes alone could not detect the vast differences in light intensity (measured in foot -candles) from one side of the room to the other. In what I considered a brightly lit room was enough light for only low light tolerant plants. Since photographers are usually the only people with light meters, how do we determine whether or not our houseplants will receive adequate lighting in the winter months and throughout the year?

There are some simple rules of thumb that we can use to help us determine where to place our plants for adequate lighting. We will break these descriptions into three categories of low, medium and high light. Read the following details slowly to determine your situation.

Low light situations occur within two feet of windows with a northern exposure October through March. April through September this changes to 2-6 feet back from or 1 foot to the side of the same northern window. For windows with southern exposures, low light exists 2 to 6 feet back from the window or 1 foot to the side. Plants are also in low light if they are 6 to 10 feet back from or 2 feet to the side of an east or west glass all year.

Medium light for plants exists within 2 feet of a north glass April to September. Plants get medium light levels 2 to 6 feet back from or 1 foot to the side of an east, west or south glass all year. Medium light levels typically occur with fluorescent lighting at 10 to 14 hours per day.

High light situations occur within 2 feet of a south facing window October through March or within two feet of an east or west glass all year. High light also occurs in areas receiving direct sunrays for 4 to 6 hours daily. (Light Definitions: Care and Selection of Houseplants by Jim Perry)

There are some variations to these descriptions that would include shading of windows, size of the glass, etc. However, the next step is to determine what plants you have, what there light needs are and what light exposure is available to them. Putting plants in the right place with the right light exposure will help you enjoy them for years to come.

These archived columns were written by Kerry Johnson, a hobby gardener, former weekly newspaper columnist and an Area Extension Horticulture Agent for 11 coastal counties in Mississippi.