Potted tropicals can do well outside during summer and then be brought indoors for winter. Photo by Dan Gill

Whether we admit it or not, heat and humidity this time of year make gardening outside less enjoyable. I have to confess to retreating into the coolness of my air-conditioned home and spending less time in the garden now that midsummer 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.

Growing houseplants successfully 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 is light. Light is the energy plants use to create their food. You cannot grow a plant without enough light, no matter how good it looks in the location.get it growing

Houseplants are available at a wide variety of sources, from nurseries and flea markets to chain store garden centers and even grocery stores. Quality is of particular importance. Always purchase plants that are vigorous and healthy with good color and have an attractive shape with no insects or diseases. Look at the foliage carefully. Avoid plants with yellow leaves, brown leaf edges or spots that indicate the plant has been poorly cared for. Look for signs of scale, mealybugs or mites that could infest your other plants at home.

Choose a plant that will survive in the location where you intend to place it – particularly in regards to the amount of light the spot receives. Different types of houseplants will grow in higher or lower light conditions. You may ask the nursery staff to help with the selection or check references on growing plants indoors before you make your final decisions. When you purchase a plant, make sure it has a tag 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 it.

Houseplants are generally 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 (in summer) to high (in winter) light levels are provided by unobstructed south-facing windows.

– North-facing windows provide low light levels. Low light levels may also be provided by placing plants several feet away from east-, west- or south-facing windows.

Although light is most often provided by sunlight shining through windows, artificial light can also be used effectively to grow indoor plants.

Place plants where you have determined they will get the proper amount of light. Within four to eight weeks, the plant will indicate if it has a serious problem. Whether there is actually enough light in the area is, after all, the plant’s decision – not yours. If no pests are present and a plant has been watered properly, a deteriorating condition usually indicates insufficient light. Move the plant to a brighter location.

People are always obsessing over how to water their houseplants. For the majority of plants, the answer is really quite simple. Stick your finger into the pot, and 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 that 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. You can use a baster to suck the water out of the saucer if the plant is too large to dump the water.

Houseplant containers should definitely 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 fit in well with your interior decor. Clay, plastic or other materials are all appropriate as long as they drain.

Only use soil specifically blended for use in containers. It’s called “potting soil.” Do not use topsoil or garden soil products or soil you dig up from your outdoor garden beds. Most potting mixes are made up of various proportions of peat moss, perlite and vermiculite because this type of mix retains water and still drains well. You must, however, regularly fertilize plants growing in these types of mixes. Make sure whatever potting soil or mix you use is loose, drains freely and does not pack tightly in the pot.

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. Given good care and time, you will see the plant rejuvenated. Then you can bring it back inside and try it in a different location when it looks better.

Dan Gill is a horticulturist with the LSU AgCenter. He can be reached at DGill@agcenter.lsu.edu.