Are drought tolerant plants the same as desert plants ?

by Ellie
(Cape Town)

There are many 'kinds' of drought tolerant plants

What is the difference ?
There is a fine line between summer drought tolerant plants and desert plants in our various South African climates. Year round drought is a feature of deserts, but summer drought, so formative of Mediterranean plants, gives way to winter rain, which equally shapes their tissues and evolution, and depending on the particular characteristics of the Mediterranean climate zones which differ from each other, the winter rain can be sparse or heavy. There are parts of South Africa which receive winter rain which would be classed as desert not 'Mediterranean' because the winter rain is so scant. This scant rain does not create the problems of heavy winter rain, which means the soil is waterlogged for weeks on end. Most desert plants cannot cope with constant moisture. Drought tolerant plants in the succulent thickets of South Africa on its south east coast are used to little rain... but not the scant rain of the deserts. They receive rain regularly throughout the year, but not often enough to maintain waterlogged soil. They also cannot survive soggy soil for extended periods.
The triumph of Kirstenbosch !
The recreation of these distant succulent thickets at Kirstenbosch, under the adabiatic clouds bringing moisture from the Indian ocean, is a triumph of gardening artifice. Under the succulent garden is a deep bed of rubble to ensure drainage. The rubble is covered with stone, and then finer gravel, before the soil was added. This drainage bed was placed by one of the earlier garden managers, Pearson. Now that you are informed you will look at this picture with different eyes. See the moisture laden air hovering before the crags of the mountain, the flowering Aloe which would not flower with the soggy feet produced by the winter rain which falls over this area if it falls nowhere else in Cape Town. It would have rotted away without the gravel bed below. See the tree growing outside the gravel bed, a rainforest tree dripping with water that sparkles in the afternoon sun. Only six kilometres away, at my home, on deep sand, not the clay taillus soil around the mountain, a place where we watch the clouds over Table Mountain from a distance, under radiant blue skies, I grow the same aloe without any artifice, and it blooms every winter to the delight of the malachite sunbirds.