Succulent plants have become so popular because they offer low maintenance and diverse shapes and textures, both in the garden and indoors. Crassula is a diverse and extensive genus of succulent plants, with about 350 species. Probably the most well-known is the jade plant (Crassula ovata). Many of us know it as a houseplant, but in warm climates, it grows into a shrub.
Crassulas range from annuals to perennials, herbaceous or woody plants, groundcovers to shrubs to small trees. Many Crassula species are small, 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. They are perfect container plants—low maintenance, evergreen, and eye-catching.
Most of the Crassulas grown as houseplants originated from the eastern cape of South Africa. If you have the climate, the plants look terrific in the garden, tucked into and hanging over walls. In zones 9a-10b, jade plants in their natural element will be one of the easiest plants to maintain in your garden. Their dark, glossy green color is a great foil for almost any flower color.
|Botanical Name||Crassula spp.|
|Common Names||Depends on species: Jade plant (C. ovata) Rattlesnake Plant (C. barklyi), Living Coral (C. argentea), String of Buttons (C. perforata).|
|Plant Type||Broadleaf perennial evergreen, often grown as a houseplant|
|Mature Size||Varies by species; jade plant can grow to 6 feet, while others are just a few inches in height|
|Sun Exposure||Part shade|
|Soil Type||Well-drained, loamy potting mix|
|Soil pH||6.1 to 6.5; neutral to slightly acidic|
|Bloom Time||Seasonal bloomer as houseplants; outdoors, they bloom mostly in spring and summer|
|Flower Color||Varies by species; jade plant has non-showy white or pink blooms|
|Hardiness Zones||9 to 12, depending on species|
|Native Area||Most species are native to South Africa|
How to Grow Crassula Plants
Depending on your climate, Crassula plants can be either garden plants or indoor potted specimens. Outdoors, most species of Crassula like well-draining soil; they will react badly to boggy, wet soils, as their roots can rot. Indoor potted plants thrive in a well-draining potting mix intended for succulents.
Given their low water needs, jades and other Crassula species are ideal for people who tend to neglect their plants. They are very hard to kill and very easy to propagate from cuttings. Even a single leaf that falls from the plant will often take root in potting mix. However, don't completely neglect your plant--it still needs water!
Crassula can be sensitive to temperature. Too hot, and they will go dormant and drop their lower leaves. Too cold, and they will simply pout, not doing much of anything. Other than that, they laugh off both neglect and abuse.
Stacked Crassula (C. perforata) sends out suckers, which is really only a problem when grown in the ground. However, they are slow growers and can be controlled with little effort. With all species, you can aggressively cut the plants back whenever they get straggly or leggy.
Aphids, spider mites, mealybugs, and other common indoor pests can affect Crassula plants; these are best treated with non-chemical means, such as horticultural oils.
Most Crassula plants need some shade in the hottest part of summer but require bright light to attain their most vibrant color. When grown outdoors, a site with morning sun and afternoon shade is perfect. Placed in full sun, the leaves can scald. When grown indoors, place Crassula plants in a spot that receives bright indirect light all day, or direct sun for six hours of the day. A southern-facing window is ideal.
Crassula plants need soil that is very well-draining, and they will do fine in sandy, rocky soils. They prefer a neutral to slightly acidic soil, but even extreme pH levels rarely kill the plant.
These are succulent plants related to the stonecrops, and they prefer sparse watering, with the soil drying out completely before being watered again. Avoid overwatering. Instead, soak the plant, allow it to drain completely, then wait for the soil to dry out before watering again. During cooler months, reduce watering, as the roots can rot in cold, wet soil. Crassula plants begin actively growing in the spring, so watch for watering needs. When grown indoors, watering should be minimized from late fall through winter, as the plants go semi-dormant during this time.
Temperature and Humidity
Crassulas can be grown outdoors as perennials in zones 9 through 12, but elsewhere you will need to bring them in for the winter or grow them as houseplants. Some species will tolerate a mild frost, but temperatures below 30 degrees Fahrenheit may be enough to kill them off. Jades and other Crassula species prefer low humidity, but they also survive nicely in very humid climates.
Feed this plant sparingly. You can give your plants a little organic fertilizer in mid-spring, as they start actively growing, but further feeding is not necessary.
Potting and Repotting
When grown as indoor plants, Crassula plants prefer a porous, somewhat dry potting mix, but one that also has some organic material in it. A cactus/ succulent mix with some extra peat moss mixed in is ideal.
Make sure the pot has good drainage, as these plants don't like to have soggy roots. Pot them up to a larger container when the plants become very overgrown—every 2 to 3 years when the plants are young, then every 4 to 5 years for mature plants. Repot in spring as needed.
Propagating Crassula Plants
Crassula plants are generally propagated from leaf- or stem-cuttings, or by dividing the offsets. Starting new plants is as easy as removing a leaf, letting a callus form for a week, then sticking the end of a leaf or stem cutting in a dryish potting mix. Keep the soil slightly moist and wait for roots to sprout.
Varieties of Crassula
There are so many species and cultivars of Crassula to choose from that you may become a collector. In addition to the standard jade plant cultivars (Crassula ovata), Here are a few others that might catch your eye:
- Crassula 'Morgan’s beauty': This hybrid cultivar has silver leaves dusted in white, with pretty pink late spring flowers. It grows about 4 inches tall.
- Crassula erosula 'Campfire': This variety has long branching lime leaves that turn blazing red in winter. It is a clumping plant that grows about 4-8 tall and spreads 2 feet wide.
- Crassula pellucida variegata : This plant exhibits a flowing mass of heart-shaped leaves variegated pink, green, and creamy yellow. It is nice in a hanging pot.
- Crassula perforata: Known as the stacked Crassula, this plant has leaves that circle around a central stem, giving it the common name, 'String of Buttons'.