Cereus forbesii is a strongly ribbed branching columnar cactus from Bolivia, Argentina and Paraguay where it grows at elevations up to 2000 metres. A very fast-growing cactus, Cereus forbesii quickly grows to a tall handsome specimen and makes an ideal and impressive indoors plant with its architectural form, long spines and glaucous-blue stem. It looks perfect in a large terracotta container with a low centre of gravity - a bowl shape is best - and should be placed in a well-lit aspect with plenty of sun. It can be moved - with care - to a patio or sunny balcony during the summer months but make sure that it doesn't get over-watered in the summer showers and that it is protected from potential snail attack. During the winter it should have no water at all and be kept completely dry.

Despite growing at higher altitudes and at relatively southerly latitudes, Cereus forbesii is not particularly cold-hardy. In its natural environment it will experience short episodes of sub-zero temperatures but it is not one to experiment with outdoors in the much harsher and wetter UK winter. If not warm and cosy indoors, it will usually do well - dependant on location - in a cool glasshouse but it is sensible to keep it under a few layers of fleece until mid to late-February