Succulents are popular for two simple reasons: they are beautiful and nearly indestructible.
Technically, a succulent is any plant with thick, fleshy (succulent) water storage organs. Succulents store water in their leaves, stems, or roots. These plants have adapted to survive arid conditions throughout the world, from Africa to the deserts of North America.
Fortunately, this adaptive mechanism has resulted in an incredible variety of interesting leaf forms and plant shapes, including paddle leaves, tight rosettes, and bushy or trailing columns of teardrop leaves.
As a group, succulents include some of the most well-known plants, such as the aloe and agave, and many almost unknown plants. Cacti are a unique subset of the succulent group. Succulents make excellent display plants in dish gardens.
No matter what kind of succulent you're growing, the rules are pretty similar among the different species. Here are the general rules for growing top-quality succulents.
Succulents prefer bright light, such as found on a south-facing window. Watch the leaves for indications that the light level is correct. Some species will scorch if suddenly exposed to direct sunlight; the leaves will turn brown or white as the plant bleaches out and the soft tissues are destroyed.
On the other hand, an underlit succulent will begin to stretch, with an elongated stem and widely spaced leaves. This condition is known as etiolation. The solution is to provide better light and prune the plant back to its original shape. Many kinds of succulents will thrive outdoors in the summer.
Temperatures for Growing Succulents
Succulents are much more cold-tolerant than many people assume. In the desert, where there is often a marked contrast between night and day, succulents thrive in colder nights, down to even 40 F. Ideally, succulents prefer daytime temperatures between 70 and about 85 F and nighttime temperatures between 50 and 55 F.
Succulents should be watered generously in the summer. The potting mix should be allowed to dry between waterings, but do not underwater.
During the winter, when the plants go dormant, cut watering back to once every other month. Overwatering and ensuing plant rot are the most common causes of plant failure. Be aware, though, that an overwatered succulent might at first plump up and look very healthy. However, the cause of death may have already set in underground, with rot spreading upward from the root system.
A succulent should never be allowed to sit in water. Overwatered plants are soft and discolored. The leaves may be yellow or white and lose their color. A plant in this condition may be beyond repair, but you can still remove it from its pot and inspect the roots. If they are brown and rotted, cut away dead roots and repot into drier potting media, or take a cutting and propagate the parent plant.
An underwatered plant will first stop growing, then begin to shed leaves. Alternatively, the plant may develop brown spots on the leaves.
Choosing Potting Soil and Fertilizer
Succulents should be potted in a fast-draining mixture that's specifically designed for cacti and succulents. If you don't have access to a specialized mix, consider modifying a normal potting mix with an inorganic agent such as perlite to increase aeration and drainage. These plants have shallow roots that form a dense mat just under the soil surface.
During the summer growing season, fertilize as you would with other houseplants. Stop fertilizing entirely during the winter.