Titanopsis calcarea

Titanopsis calcarea is a curious and rather special mat-forming succulent from Cape Province in South Africa. It has small rosettes of greyish fleshy foliage with small warty idioblasts covering the end of the flaring leaf surface. It slowly forms a clump and produces a yellow flower. In its natural habitat it thrives on alkaline soils, blending in with the rocky shale scree surfaces in which it grows.

Titanopsis calcarea requires full sun and a very well-drained substrate. It adapts well to life as a houseplant in a terracotta container if given an aspect that receives lots of light. A south-facing window-sill is ideal. One of the hardiest of all the South African succulents it is capable of surviving extreme sub-zero temperatures but only if it is kept perfectly dry. If you do experiment with it outside you will need perfect drainage - preferably in a raised bed - with lots of grit, perlite and added limestone together with a rain shelter for the winter.

It needs very little water, even in the growing season and none at all from October through to March. Generally pest-free but - as with all succulents - you should keep a keen lookout for mealybug which can lurk in the folds of the foliage.