Many other Crassula species are much smaller, including some miniatures and creeping ground covers. They are all quite fascinating, the types of plants you see occasionally and wonder "What is that?" With the resurgence of succulent container gardening, these smaller Crassula species are becoming more readily available and their easy growing habit makes them worth getting to know.
Growing Conditions for Crassula
Crassulas are among the most popular succulents to grow in gardens or containers both indoors and outdoors.
Light: Crassula plants prefer full sun to partial shade. However, intense afternoon sun in the hottest period of summer can burn the leaves of the plants. A place with morning sun and afternoon shade would be perfect. Many Crassulas will stress beautifully to shades of red, purple, pink, orange, or yellow in response to more sunlight. In low light, even the reddest plants will revert to green.
Most Crassulas can be grown indoors if given enough light. Place your plants in a southern window where they receive at least 6 hours of direct sunlight.
Soil: Crassulas are not particular about soil pH, but they require very porous soil with excellent drainage. Most of them will do well in sandy or even rocky soil. Use commercial potting soil mixes designated for use with succulents or mix your own. In habitat, Crassula plants usually grow in rocky quartz fields.
Temperature: These succulents prefer average summer temperatures between 65 and 70 ºF (18 and 21 ºC). In winter, cold to 50 ºF (10 ºC). Most Crassulas will tolerate some small degree of frost, but extremes of cold or heat will cause them to lose leaves and die. The biggest challenge with outdoor plants in winter is protecting them from temperatures below 32 ºF (0 ºC). Most species are grown outdoors in USDA hardiness zones 9 to 10, 20 to 40 °F (-6.7 to 4.4 °C). However, elsewhere you could bring your potted plants indoors for the winter.
General Care for Crassula
Crassulas are easy to care for as houseplants or in the garden. They are perfect plants for beginners.
Watering: These plants have typical watering needs for succulents. Avoid overwatering by using the "soak and dry" method, where the soil is soaked with water, slowly drained and left to dry out before watering again. Reduce watering in winter, as your Crassulas can lose its roots if the soil stays cold and wet for extended periods. Too little water may cause the lower leaves to fall off. In habitat, the leaves shrivel as plants draw on stored moisture, then plump when rains return.
Potted plants require more frequent watering than those in the ground.
Fertilizing: Crassulas are slow-growing succulents and do not need much feeding. They will benefit from a small amount of organic fertilizer in mid-spring when they start actively growing.
Repotting: Many Crassulas do well in the same container and soil for many years. Repot as needed, preferably in spring, at the beginning of a period of active growth. Make sure the soil is dry before you begin repotting, then gently remove the pot. Knock away the old soil from the roots and place the plant in new or the same pot with a fresh potting soil mix. Leave you Crassula dry for a week or so, then begin to water lightly to prevent root rot in your plant.
Pruning: Crassulas can benefit from occasional pruning to keep them healthy and compact. When plants start to get straggly or leggy, do not be afraid to cut them back. The pruning is best done in spring or after the blooming.
Crassula ovata and Crassula arborescens, including their cultivars, are a popular choice for bonsai lovers. Many who learn bonsai begin with C. ovata.
Varieties to Grow
There are so many to choose from, you may become a collector. Here are a few that might catch your eye.
- Crassula "Morgan’s beauty": Thick silver leaves dusted in white, with pretty pink late spring flowers. Grows about 8 inches wide.
- Crassula erosula "campfire": Long branching leaves turn blazing red in winter. A clump former that grows about 1 ft tall and spreads 3 ft wide.
- Crassula pellucida subsp. marginalis "variegata": A flowing mass of heart-shaped leaves variegated in pink, green, and creamy yellow. Nice in a hanging pot.
- Crassula perforata: Known as the stacked Crassula, their leaves rotate around a central stem, giving them their common name, 'String of Buttons'.
Crassula plants are generally nontoxic to people. Crassula ovata is slightly toxic to cats, dogs, and some other animals.
How to Propagate Crassula
Crassulas are generally started by leaves or stem cuttings. They can also be grown from seeds and offsets.
Propagation: It’s easy to start a new Crassula from leaves or cuttings taken from an established plant. Snip a leaf from the plant and allow it to dry for a few days to form a callous, then tuck the cut end into a pot of moist potting mix. Place the pot in bright, indirect light. Roots should begin to form in a week or so.
To propagate a jade plant from a cutting, snip a 3- to 4-inch branch from your established plant and set it aside for a few days to dry. After a callous develops on the cut end, place the cutting upright in potting mix and water lightly. Roots should begin to form in a few days.
Crassula plants can start quite small but over time can grow into a large and majestic specimen. If, after a few years, the plant becomes overgrown and awkward, use a pair of sharp pruning shears to prune it to a more suitable, attractive size and shape. You can prune any time of year, but the plant recovers more quickly during the active growing seasons of spring and summer. Root the cut stems and leaves to grow more plants.
Offsets: Propagating Crassulas with offsets is very easy because the parent plant has already done the majority of the work for you. To divide the offsets, brush away the topsoil until roots are visible, and gently pull them apart. Let the offsets dry out for several days and place them in a well-draining soil mix.
Seeds: Propagating Crassulas with seeds is the slowest way to grow new plants. Sow the seeds in the spring or summer. They germinate best at temperatures below 70° (21 °C). Do not cover these seeds and other tiny seeds with a top layer. Avoid direct sunlight exposure. The seeds usually start to germinate after 1 to 3 weeks. Seedlings can be transplanted to individual pots when they have at least three leaves.
Pests and Problems
Keep an eye out for the usual succulent pests: aphids, mealy bugs, and spider mites. The biggest problem is root rot and sparse watering will help avoid that.
