Succulents have been a favorite of expert gardeners, novices and collectors for years. Succulent is a classification given to plants which store moisture in their leaves/stems due to living in dry environments. Not all succulents are equal as far as ease of growing in a garden – some do not handle any frost, while others are very sensitive to soil moisture. They are a great addition to a garden though, and with some tips and tricks they can easily blend in with California natives, Mediterranean low-water plants and other garden favorites.
Most succulents are easily propagated from stem cuttings. However, unlike herbaceous stems, succulent cuttings should be allowed to callus over. This means the wound should harden and dry before putting the cutting into a soil media, otherwise you run the risk of it rotting. This step can be bypassed for some easier-to-grow succulents such as Echeverias and Sedums. Cacti, Euphorbias and Aloes. Almost all others should be allowed to callus. This can take anywhere from a few days to weeks.
During this time, cuttings should be placed upright in a shady, dry environment. The reason to keep them upright has to do with the gravitational movement of auxin (the hormone responsible for root formation). Auxin (formed at the growing tips) moves down the stem with gravity. If you lay your cuttings on their sides, auxin will pool on the side closest to the ground, promoting more root growth in that region. To guarantee balanced root formation, be sure to keep cuttings upright.
Besides stems, some succulents can be propagated from leaves. Echeveria, Graptopetalum, Sansevieria and Gasteria are the best-known ones. Ideally the newer leaves will be used with this technique, as the growth hormones are strongest in these. Lay the leaves on top of potting soil, pumice or sand. Roots will start sprouting from the base end of the leaf followed by a new plant. Very simple!
A big mistake most people make is watering their succulents right after planting or transplanting. During this process, many wounds are created on the roots, and as aforementioned, succulents tend to be very susceptible to rot. To prevent this, plant in dry soil, leave for a few days (depending on the size and species of succulent) and then water. This goes for pots as well as in-ground beds.
Soil for succulents
Like California native and Mediterranean plants, succulents do best with good soil drainage – especially in winter. To ensure this, either plant on a raised mound of soil or incorporate red lava fines (dust) into your soil. If growing in a pot, a succulent mix is a must – aim for 60 percent inorganic material (such as pumice/red lava and sand) and 40 percent redwood compost and peat.
The most well-known Aloe is Aloe vera, primarily due to its medicinal properties. However, Aloe vera is less frost tolerant than many other Aloes. Plus, in my opinion, it is not as beautiful as others. Aloes tend to bloom in late winter and early spring, and are ideal as a food source for hummingbirds. Though some aloes will tolerate frequent irrigation, they are best with other dry-loving plants.
If you are looking for a tall focal point in your garden, consider Aloe ferox or Aloe africana. These single-trunked, slow growing plants will eventually reach 8 to 12 feet in height. If you have a large, hot, dry area, consider planting the shrub A. arborescence. Coral aloe (A. striata) is a relatively spineless, easy garden performer. All these aloes can handle brutal summer conditions, full sun and not a drop of water (but will look better with some).
Echeverias fall into the “cute” category of succulents. Spineless, tidy growing and small, these members of the Crassulaceae family are great for pots, garden edges, growing over rocks or meandering under taller shrubs. Native to Mexico, most can handle some frost. They can also handle full sun, but in hot inland climates they do look better in afternoon shade.
For the most part all have the same growth pattern, spreading by rosettes. Species and hybrids vary among the size of rosettes, appearance of foliage and flower color. Most gardeners, however, grow them for their foliage. Some, such as Echeveria “Perle von Nurnberg,” have opalescent purple foliage while others have pink edges and muted pinks, all the way to blue and purple hues. A few noteworthy ones are E. elegans, E. colorata and E. x imbricata.
It’s hard to not fall in love with Sedums. Another member of the Crassulaceae family, this genera consists of many species of trailing, low growing plants – but also contains some noteworthy taller species. Once such plant is the sun-loving Sedum “Autumn Joy.” Growing to about 2 feet in height, this plant is known for its longer-lasting, pink-to-bronze flower clusters. These butterfly-attracting flowers bloom midsummer into fall. Come spring, cut the old foliage down for new growth to occur.
Sedum cauticola, another must, reaches 6 inches high, with clusters of pink summer flowers on blue/gray foliage. Low-growing, trailing Sedums can handle full sun, but once again in inland hot climates they will benefit from afternoon shade. Some noteworthy ones are S. spurmium ‘Tricolor’, S. hispanicum and S. clavatum.