Cultivation

Haworthia picta Klipdrift, S. Oudtshoorn

Haworthia & Gasteria

How to grow them?

Most of the plants from genus Haworthia and Gasteria are not difficult, you can grow them as other succulent plants. In Winter they excuse temperatures as low as 5 degrees. In Summer they welcome good ventilation.

In nature – in South Africa, Haworthias and also Gasterias grow mostly in shadow of bushes, grass or among rocks. This ensures them protection from direct sun and domestic animals (sheep and goats) which consume them without hesitation. Just a few species, e.g. H. leightonii, H. glauca, H. coarctata or H. reinwardtii grow in direct sunlight.

Significant advantage in growing is that more than 75% plants can grow for a long period in a 7cm pot and it is not a problem to house quite a large collection in a small greenhouse or window parapet. The largest Haworthia specimen grows to max. 15-20 cm in diameter (e.g. H. maxima, H. kingiana or H. marginata). Genus Gasteria belongs to larger succulents (in size) – some species are in mature size almost 1m when mature (e.g. G. acinacifolia, G. croucheri and others), but we can also find smaller species like G. baylissiana, G. elaphiae, G. glauca or G. glomerata.

How to water them?

It depends on the soil mixture you are using. I grow my succulents in pure pumice. I water my collection in growing season (in Spring – from March / April till July and in Autumn from September till November) once every week. In winter every two or three weeks (because I have a quite high temperature in my greenhouse – around 15 degrees during night and day) and in Summer, during days with the highest temperature, I stop watering.

In my case, when I´m using pumice, where there is not much sustenance at all, I have to fertilize my collection every three or four weeks. I use Wuchsal Super in a lower density. A basic rule is to use fertilizer with a balanced ratio of Nitrogen-Phosphorus-Kalium.

Haworthia maraisii Crodinie

In contrast to other genera, Haworthias and Gasterias are not so tasty for pests. Rarely you find “Mealy Bugs” (a white fluffy mass appears on plant or roots). The worst threat is, in my opinion, watering at the wrong time in combination with no fresh air circulation – water can stay in the middle of the rosette and the plant will rot immediately. The characteristic smell shows that something is going wrong.

Which substrate to choose? In case of Haworthias and Gasterias it is not difficult. The main requirements are leakiness and airiness. You can use normal substrate designed for succulents. Lot of nurseries and specialized collectors use pumice. It is a kind of soil volcanic origin. I have got my whole collection in pure pumice and have great experiences with it. The only disadvantage I found is, that plants run dry very quickly and I have to water them more often – also in Winter.