Cacti and other Succulents, botanically belong to the succulent family. Succulent plants find their native habitat in dry desert areas where the rainfall is low, yet the plants can still survive.
Growing Conditions at Home
As you would expect almost all cacti and succulents do best when kept warm, quite dry and in a sunny area.
Cacti especially when grown indoors like a south window, but most varieties will tolerate more limited sun, provided that light comes from an east or west window. As a general rule, the more sun the better they like it.
Water A Critical Part of Culture
Watering cactus and succulents is perhaps the most critical and important part of succulent culture. Just looking at the the conditions they experience in nature will tell you they must be treated differently from your other houseplants.
Late spring and summer months are the seasons of maximum growth, which is then followed by a by a period of dormancy or “rest period” when they hardly grow at all.
In the summer, especially if kept indoors, cacti and succulents can be watered just like your other plants — in other words, they should receive enough water so that the top of the soil does not feel dry to the touch. When winter rolls around, it is a different story.
During the winter period, water sparingly, give the plants just enough water or moisture to keep the soil from completely drying out. The plants are almost dormant, they cannot take advantage of the water, and overwatering will just lead to the roots rotting. With cacti grown in small pots, which includes most indoor varieties used as house plants, watering from the bottom is usually a better choice. This allows the moisture soak up through the drainage hole until it wets the surface of the soil.
These plants are extremely susceptible to stem rot and any water left standing at the base of a saucer can increase the chances of rot. Some varieties like Mammillaria can cover the top of the soil surface making it difficult evenly water the plant down to the roots.
When your cacti or succulents hit the point of repotting, wait until their active summer period before stepping the plants up. They need to be in a growing state to handle the change in environment.