Daniel Gill, Merrill, Thomas A. | 6/29/2005 2:15:33 AM
By Dan Gill
LSU AgCenter Horticulturist
Whether we admit it or not, heat and humidity this time of year make gardening outside less enjoyable.
Certainly I have to confess to retreating into the coolness of my air-conditioned home and spending less time in the garden now that mid-summer has arrived. But when I don’t spend as much time in my outside garden, I can turn to my collection of indoor plants to keep me happy.
As it is with growing plants outdoors, successfully growing houseplants starts with understanding their needs. Houseplants contribute to and become an important part of the interior decor, but they are not furniture or knickknacks. They are alive and, like all living things, they have certain requirements that must be met to be healthy.
Primary among these needs is light. Light is the energy plants use to create their food. You cannot grow a plant where there is not enough light – no matter how good it looks in the location.
Houseplants are available at a wide variety of sources, from nurseries and flea markets to chain store garden centers and even grocery stores. But quality is of particular importance when you’re purchasing plants.
Always purchase plants that are vigorous and healthy, have good color, have an attractive shape and don’t appear to have insects or diseases. Look at the foliage carefully. Avoid plants with yellow leaves, brown leaf edges or spots, which indicate the plant has been poorly cared for.
Choose a plant that will survive in the location where you intend to place it – particularly in regard to the amount of light the spot receives. Different types of houseplants will grow in higher or lower light conditions. Ask the nursery staff member to help with the selection, or check reference books and so forth on growing plants indoors before you make your final decisions.
When you purchase a plant, make sure there is a tag in the pot with the name of the plant on it, especially if this is a spur-of-the-moment purchase of a plant you are not familiar with. Without a name, you cannot look up or ask someone for information about the plant later.
Houseplants generally are grouped into high-light, medium-light and low-light categories. These generic terms have no clear meaning to most people, so here are some helpful guidelines:
–High light levels are provided by unobstructed east-, southeast-, southwest- and west-facing windows.
–Medium (summer) to high (winter) light levels are provided by unobstructed south-facing windows.
–North-facing windows provide low light levels. Low light levels also may be provided by placing plants several feet away from east-, west- or south-facing windows.
While light most often is provided by sunlight shining through windows, artificial light can be used effectively to grow indoor plants.
Place plants where you have determined they will get the proper amount of light. And remember that you rarely have to worry about plants receiving too much light indoors.
Within four to eight weeks, the plant will indicate if there is a serious problem. Whether there is actually enough light in the area is, after all, the plant’s decision – not yours. If there are no pests present and the plant has been watered properly, a deteriorating condition usually indicates insufficient light. So move the plant to a brighter location if you see those signs.
Another area in the care of houseplants is watering. People are always obsessing over how to water their houseplants. For the most plants, it is really quite simple. Stick your finger into the pot. If the soil feels wet or moist, don’t water. If the soil feels dry, water.
Do not allow plants to wilt before you water them. This stresses them and can cause leaf drop, flower bud drop and brown leaf edges.
Apply water until some runs out of the pot’s drainage holes and into the saucer underneath. That way you know you have moistened the entire root ball. Do not let the pot sit in a saucer full of water, however. Remove the water in the saucer if it is still there a few hours later. (Use a baster to suck the water out of the saucer if the plant is too large to dump the water out of the saucer.)
Houseplant containers definitely should have drainage holes. There must be some way for excess water to drain out of the soil when we water. Otherwise, we run the risk of the soil staying saturated, drowning the roots and encouraging root rot.
Choose pots you find attractive and that fit in well with your interior decor. Clay, plastic or other materials all are appropriate – as long as they drain.
When potting up plants, only use soil specifically blended for use in containers called "potting soil." Do not use topsoil or garden soil products or soil you dig up from your outdoor garden beds. Make sure whatever potting soil or mix you use is loose, drains freely and does not pack tightly in the pot.
Since virtually all of the plants grown as houseplants are native to the tropics, they should not be exposed to freezing temperatures. Generally, avoid temperatures below 45 degrees, although most will tolerate temperatures down to the low 30s. Also avoid extremely high temperatures (as in leaving plants in a parked car with the windows rolled up on the way home from the nursery during the summer).
In most cases, however, the normal temperatures we maintain inside our homes are just fine for most houseplants.
If you have a houseplant that has not been doing well indoors, try moving it outside to a shady location for the rest of the summer. With good care and time, you may see the plant rejuvenated, and you can bring it back inside and try it in a different location when it looks better.
Get It Growing is a weekly feature on home lawn and garden topics prepared by experts in the LSU AgCenter. For more information on such topics, contact your parish LSU AgCenter Extension office or visit our Web site at www.lsuagcenter.com. A wide range of publications and a variety of other resources are available.