Most houseplants come from tropical or subtropical areas of the world and may be wildly different from the native plants growing outside your door. Indoor plants typically come from the tropics because they can tolerate the warm temperatures people are most comfortable living with indoors. While growing plants indoors is a relatively simple process, you must be aware of each plant's individual light, water, humidity, fertilizer and temperature requirements, which may differ greatly from the other plants.
Provide each plant with a pot large enough to support its above-ground growth and allow room for its roots to grow under the dirt, too. The pot should, for most plants, be filled with all-purpose potting soil. Some varieties, like cactus and succulents, may require special soil, such as sandy quick-draining blends.
Consult the tab in the plant pot or a garden guide (see Resources) to find out what sort of light, temperature and moisture the plant requires.
Provide the appropriate type of lighting. Depending on the plant, this will mean placement in a sunny window with bright or direct light; exposure to indirect light by being placed near the window but not directly in it; or dim light, away from the windows.
Monitor the dampness of the plant's soil both by looking at it---very dry soil is obvious at a glance---and testing it with your finger. Don't just touch the surface of the soil; probe about an inch down with your finger to find out how damp or dry it is below the surface.
Water your plant regularly to meet its needs. Most tropical houseplants will do just fine if you water them immediately once the top inch or so of soil is dry, but some, like cactus and succulents, must be allowed to dry out completely between waterings. Others, like the shamrock plant, should be kept constantly moist.
Maintain a constant temperature between 60 and 86 degrees Fahrenheit; this will be comfortable for most tropical house plants, although specific plants may have additional needs. Take care not to place your plants too near to the heater or a cold draft from a window or a door.
Fertilize most houseplants every two to four weeks. If the leaves turn light green, fertilize more often; if leaves are dark green but abnormally small, fertilize less often.