By Eileen Price, Colorado Master GardenerSM, Colorado State University Cooperative Extension, Denver
Don't confuse your houseplants with their outdoor relatives. If indoor and outdoor plants are related at all, it's a distant relationship indeed.
A house plant has a laundry list of conditions to which it must adapt: dry air, low light, low humidity and artificial heat in winter. Some consideration of your houseplant's needs now will pay off with lush, healthy foliage throughout the year.
Locate the right plant in the right place. Plants usually grow well on window sills or table tops. A word of caution: When the temperature drops below freezing and the windows are covered with frost, remove plants from window sills during the night and put them back in the morning.
If a plant needs more humidity than a window sill can offer, put it near the dishwasher or in the bathroom near the shower. A plant might even sit in the bathtub, where it could easily receive a daily misting.
Watering can be tricky. Plants can easily be killed by over watering. This writer's favorite cactus met its demise by over watering last winter. Too much water and it fell into a soggy heap.
For most plants, water when the soil surface begins to dry. Use the "feel" test to determine if the soil is dry and hard. If the soil looks light colored, it's usually time to water. If it feels damp or muddy and looks dark, wait a few days.
You'll need more water in heated rooms during the winter. The water you use should be at room temperature. Plants must be kept evenly moist, particularly if they are in a light, humus-type soil. Too much water subjects them to root rot. Be sure to provide adequate drainage.
For those plants that seem to need more water, pots should be placed in a saucer that contains gravel; the gravel can be covered with water. Change the water every few days because stagnant water is a good breeding place for insects.
Many plants with coarse roots, such as dracena and philodendron, generally are kept on the dry side.
Light needs vary with the type of plant. Check the tag that comes with the plant when it's purchased. A particular plant may not need a sunny window or a shady corner -- more is not always better. Some plant's leaves may be sensitive to the sun and may become scalded.
If a plant needs light, but sunlight isn't available, you can use artificial light. In most cases, low light will result in spindly, weak growth.
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010