The genus crassula includes dozens of species of succulent plants, originating in central and southern Africa; it is a plant with succulent leaves, thick and fleshy, arranged in thick rosettes or developing on stubby branched stems, also succulent. Most species fear the cold and are not suitable for cultivation in the garden, therefore they are grown in pots, in a cold greenhouse or at home; some species, in particular some of the creeping species, can easily cope with short periods of frost.
The Crassula ovata
One of the most cultivated species is the crassula ovata, also in the hobbyt variety with particular leaves; it is a small, completely succulent shrub, with large, well-branched, fleshy, brown stems, on which small fleshy, oval, green leaves develop, which easily tend to turn red in the event of prolonged exposure to the sun or frost .
It is a widespread plant, both among lovers of succulents, and among those who engage in the cultivation of bonsai.
At the end of winter these plants produce thin stems, which rise from the foliage, and which bear inflorescences consisting of innumerable small white flowers in the shape of a star, very pleasant.
These are plants with rapid development in the first years of life, then tend to develop slowly, if grown under the right conditions; specimens of many years can reach up to 100-120 cm in height; with time they tend to constitute a short trunk, similar to the trunk of an ancient tree, and a thick roundish, well branched crown; It is this "tree" aspect that makes the ovate crassula very suitable to be cultivated as bonsai.
They are cultivated in not excessively large containers, as their root system tends to remain modest in size over the years; the growing substrate must be very well drained, not particularly rich; it is generally used the specific earth for succulent plants, or for citrus fruits, with added dis ha, to increase its drainage. They do not need to be repotted every year, even if it is not bad to repot them every 2-3 years, above all as regards the young specimens.
Watering is only sporadic, when the soil remains dry and the climate is dry, in summer; more or less from May to September every 8-10 days. Every 20-25 days, during this period of the year, let's remember to add to the irrigating water a small amount of fertilizer for succulent plants, but let's avoid excesses.
In the cold months we avoid watering the plants.
These crassula can withstand temperatures close to -5 ° C, so in winter we can leave them in a cold greenhouse, or on the terrace, in a fairly sunny place, preventing them from receiving water from the watering. We can also shelter them at home, even if the dry climate of the apartment causes the cochineal to proliferate, and moreover the specimens kept constantly in a simulated spring climate tend not to bloom practically never, depriving us of this very pleasant characteristic.
Also the arborescens species enjoys qualities similar to the crassula ovata, and is just as easy to grow.
Crassula - Crassula: Collector's crassulae
There are some varieties and species of crassula certainly from collectors, since they have climate and soil requirements that are difficult to achieve by those who simply love to keep a couple of pots in the living room. The most widespread species are hybrids with special names, such as Morgan's beauty or Buddha's temple; they are tiny-sized plants, which do not exceed 10-12 cm in height, with beautiful, very compact foliage, in narrow rosettes, which produce beautiful pinkish inflorescences if properly cultivated in spring.
Cultivation is not simple, because they need the right soil, the right humidity and the right insolation throughout the year; if the cultivation conditions are not ideal, the plants tend to mumify, or to stop developing almost completely, or they are prey to parasites that quickly ruin them.