Crassulas are native to South Africa. They come in different shapes and sizes. Some looking like shrubs or bonsai trees (Crassula Ovata), through to mounding and tower types (Crassula Transvaal Drakensberg and Perforata respectively). There are roughly 350 different species of Crassulas and I have found it that the Shrub/ Bonsai types are best to be planted in the garden or a decorative pot. It is also therapeutic to cut off and train the limbs to produce an elegant masterpiece. Whereas the mounding and tower types present beautiful shapes, colours and textures. Unfortunately, these grow a lot slower than the others and will present well in small decorative pots or Vertical gardens.
Crassulas prefer mild, frost-free regions with low humidity (but not desert heat). Rule of thumb is that the thicker the stem, the more drought-tolerant the Crassula is. So, the Ovata is a perfect example of a Crassula that thrives on neglect as it stems can grow quite thick, where say, Crassula Buddahs Temple would need watering more often (thin stem). The Crassula will tell you when it needs watering. It will show signs of dehydration when its leaves start to shrive (it is screaming for a good soaking).
Like most succulents, Crassulas should be grown in the full sun. However, there is one exception. I find it that the tower Crassula best grow slightly protected (under a frost cloth or 30% greenhouse). By doing this it will help keep your Crassulas compact and expressing some of the most beautiful shades of red, yellow and orange. If grown in low light, even the Crassula with the brightest colours will revert to green.
The most common pest and diseases Crassulas suffer from are Mealy Bug and Powdery Mildew. The biggest challenge with these simple succulents is protecting them from temperatures below 0 degrees C.
A remarkable thing about jades is that random limbs will shrivel and fall off. This enhances air circulation, allows more sunlight to enter, and starts new little plants. Eventually you get a sort of bonsai, a nicely balanced shrub that resembles a small tree. This is most noticeable in old potted specimens with thick trunks. Remove any baby plants if you don't want them.
How to take stem cuttings from shrub crassulas? Cut a stem off the mother plant, removing the leaves from the bottom of the stem. Then let the stem callous over before putting the stem into a well-draining soil mix. A home remedy used to increase the callousing stage is to put cinnamon powder on the open wound and once it has fully calloused over, rub honey on the same area and stick into the soil. Honey has a natural hormone that can stimulate root growth. Stacked Crassulas are basically the same. However, you can plug them straight away as their stems are much thinner and will callous over within hours. Crassulas are best to be propagated in late Autumn throught to mid Spring. During this time frame I like to fertilise these at 50% strength once a month (with the use of Sealsol at quarter strength between fertilising). Don’t forget, LESS MORE OFTEN and when a plant is in active growth add fertilising into your regime and when it’s in hibernation, Seasol is king.
Happy Gardening