
All cacti are succulents. So are all agaves. Technically, yuccas are too, even though they are no more succulent than palm trees. Perhaps that is why succulents have a reputation as xerophytic plants. In other words, succulents are supposedly drought tolerant. Most of these examples are. However, there are more succulents than cacti, agaves and yuccas.
Cacti, agaves and yuccas, as well as some of the euphorbias, are the spiny succulents. It is how they defend themselves from hungry herbivores within their natural ecosystems. Although they have a reputation as xerophytic, some uncommon sorts are quite tropical. Some can grow quite big, and because of their spines, can become difficult to work with.
Fortunately, many other succulents are neither as spiny nor as potentially cumbersome. However, contrary to popular conception, many of them are also not as xerophytic. Many that can survive with minimal irrigation perform better with occasional irrigation. Several require regular irrigation. Succulents should not be synonymous with drought tolerance.
Aeoniums, or houseleeks, can easily survive with minimal irrigation for a significant time. However, their otherwise luxuriant foliar rosettes partially defoliate to conserve moisture. With regular irrigation, they are lush, sculptural and colorful. Some are rich bronze while others exhibit delightful variegation. Aeoniums are among the more popular succulents.
Almost all small scale succulents, and a few larger ones, are easy to grow from cuttings. Clumping sorts, such as echeveria, are about as easy to propagate by division. Cuttings or pups of most sorts can be plugged directly where new plants are desirable. They only require frequent watering as they disperse roots. Then, they need only regular irrigation.
Also, almost all succulents can grow in pots. Cacti merely require very efficient drainage. Some big and spiny succulents, though, are not as portable as other potted plants. Large cacti can break if jarred. Agaves can get too heavy and broad to move safely. Otherwise, confinement of roots within pots is no problem. Some potted plants can be houseplants.






From a simple picture, Spanish bayonet, Yucca aloifolia, is indistinguishable from the common giant yucca. The narrow leaves are about two feet long, and flare upward and outward from terminal buds. Plump conical trusses of waxy white flowers with purplish highlights stand vertically just above the foliage. The main difference is that the leaves are more rigid than they appear to be, with nastily sharp terminal spines.
Yuccas are almost as useful as aloes are for gardening in chaparral or desert climates. I say ‘almost’ because most are not quite as friendly. The leaves are outfitted with nastily sharp tips. It is how they protect themselves from grazing animals in the wild, but it is not such an advantage in home gardens. Some actually have the potential to be dangerous where someone could bump into them. The leaves of Joshua tree can puncture leather. Some types of yucca get so big that they make it difficult to avoid their nasty leaves, even if planted in the background.