Copiapoas are regarded by growers as choice South American cacti, probably because they are usually slow growing and can take many years to achieve their mature appearance. One of the slowest growing is C. columna-alba, a sought-after species described by Friedrich Ritter in 1959. It is sometimes considered to be a subspecies of C. cinerea, the Chilean habitat distribution of which is just to the north of that of C. columna-alba.
Fig. 1 Habitat of C. columna-alba GC 304.01 at Esmeralda, north of Chañaral, Chile 250m
C. columna-alba is spectacular in its natural environment, where it occurs as populations of ancient plants that rarely branch, often on flat areas of coarse sand, where all the plants lean to the north, ie towards the sun in the southern hemisphere.
Fig. 2 Tray of seedlings of C. columna-alba GC 304.01 from Esmeralda
Growing copiapoas from seed is a very rewarding process and, if the seed is collected in habitat, the seedlings can exhibit significant diversity. The picture shows a tray of seedlings grown from seed collected near Esmeralda in Chile. Although from just a few fruits, the plants are variable, the differences becoming less apparent as the plants age. Depending on the growing conditions, it can take 10 years before seedlings of C. columna-alba start to flower, the plant in the picture being about 15 years old. You can just see the start of the white waxy bloom that covers plants in the wild. This protection against the intense sunshine of the Chilean coast is poorly developed in plants cultivated in Britain.
Fig. 3 Flowering seedling of C. columna-alba GC 304.01 from Esmeralda
Copiapoas are not difficult to grow, just slow. I use a largely mineral soil with little humus and keep them in a sunny, well-ventilated place. In the growing season I water them overhead with a fine rose in the evening to simulate the fog that occurs in their almost rainless habitat. Ventilation is important, otherwise there is a risk of scorching early in the year. Although very sunny, there is always a wind off the cold sea in nature.
Graham Charles
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