Growing cacti indoors is a relatively simple process. Although most cactus plants tolerate neglect, they thrive properly when given good care. These plants are mostly adapted to dry conditions. Most of the cactus varieties differ enormously in shape, size, color and flowering habits. Although most of these cacti are found in the desert regions, some are also observed in jungles. As many as two thousand different species of cacti are found in nature. This opens up enormous opportunities for those people who are particularly interested in growing cacti indoors. The majority of cacti are native to America only. These plants usually differ in size from a few inches to giants, which normally exceed the household space.