Never allow plants to remain wet in theirfor long periods, is almost standard advice when the experienced plantsman is asked for his, or her, advice on . However, there are a few exceptions to this rule, and the moisture-loving, rush-like cyperus is one of them. The loam mixture must be kept permanently wet, and it is usually advisable to allow the plant pot actually to stand in water (for most pot plants this would almost certainly mean a quick death). develop grass-like growth at the top of slender which give an umbrella appearance, hence the common name. Stalks of C. diffusus are about 60cm/2ft tall and more numerous than those of C. alternifolius which attain a height of 1.8-2.4m/6-8ft even when plant are confined to pots. Dividing mature clumps is the best method of .