The weird shapes of these fleshy plants are an endless source of fascination, especially when exotic flowers bloom on them. The flowers of cacti are particularly exquisite and brilliant. Some grow like single stars, some in clusters or circlets. But do not be surprised if some only flower every seven years or so: they are worth waiting for!
They thrive on neglect and are almost the only plants that need no watering when you go on holdiay. In addition, they are untroubled by central heating or air conditioning.
Cacti come from desert places where rainfall is infrequent, and the plants are designed to absorb rapidly any moisture that comes their way and to store it. The last thing they need is soggy soil or a damp atmosphere. A number of other succulents (fleshy-leaved plants) share these characteristics, but not all.
Cactus Care
Those bought in pots will already be in the kind of compost they like. If you transplant, mix into some John Innes Potting Compost No. 2 an equal volume of sand, or buy a bag of special cactus compost. Once a year remove the top inch of old compost and put new in – or, if the cactus has grown much, put it in a larger pot of new compost. This is better than giving fertilizer. Cacti (and some other succulents which need the same conditions) like to have more water when growing than when resting. Most grow in the summer (the Zygocactus, which flowers at Christmas, is an exception), and need very little attention in winter except to keep the soil from drying out completely. Only Lithops prefer dry soil in winter. Do not water on really cold days. If the surface of the compost is caked, break it up gently to let the water through. Occasionally, stand the pot in water for half an hour then drain very throughly. As spring progresses increase the water gradually. How often you water will depend on the weather: in a cool summer, once a week would do, in a hot one water might be needed daily. Either too much or too little water can cause brown patches or softness of the plants. Occasionally, turn the pots round so that the plants grow evenly.
The more sunshine the better – particularly in the fresh air during summer rather than behind glass (though a south-facing window-sill is ideal in summer). But in cold, damp weather, cacti are at their most vulnerable and should be put in a fairly warm, light and airy place away from draughts: few window sills are safe in winter. Repot when the plant gets too big (the method is the same for any other plant) but always do this in warm weather. Another job for a warm day is syringing any plants that are dusty.
Displayin Cacti
Small cacti are very suitable for miniature gardens. A porous container or one with drainage holes is essential. Don’t mix cacti with other succulents unless their growing needs are the same: some have different light, water and compost needs.
Another way to arrange a collection of suitable cacti is to use a windowlike display case, provided it is sunny and draughtproof. A shelf could be built out from the sill, or a series of small shelves put in at each side, equipped with plastic drip trays of the same size. The trays should be filled with gravel or pebbles so that the pots do not stand in their own drips after watering. Or build a glazed framework outside a sash window and use this as a small conservatory. In winter leave one sash open at night so that the warmth of the room reaches the plants. It is also important to cover the outside glass at night (with paper or other material) to prevent the external cold affecting the plants. Some cacti and succulents suitable for growing indoors are: Haworthias. Dark green to brown stemless rosettes of leaves, some varieties looking rather like Pine cones. Flowers are greenish-white, small and appear to have lips. These succulents prefer shade, otherwise they are easy to grow. Aloes. Very mixed group of plants, varying from dwarf rosettes of leaves to almost treelike specimens and climbers. Flowers are usually tubular, orange or red and borne on long central stems. Very tolerant plants to grow under the general conditions described above.
Gasterias. Extremely popular because they are easy to grow. Stemless leaves, dark green to brown with attractive white markings, often grow sideways from each other, not forming a complete rosette. Reddish, green-tipped flowers are carried on long curving stems. Rebutias. A beginner’s delight, they grow easily and flower freely. They are bright green, dwarf, clustered plants. Sometimes webby and sometimes spiny, they have stemless flowers in various shades of red and yellow. Opuntias. Varied genus in appearance, the most common varieties usually having large, flat, green, spiny or hairy stems which grow out of each other to give a sculptured appearance. The open flowers – red or yellow – grow straight from these and are produced freely. Some even fruit and a few are edible.
Epiphyllums (previously called Phyllo-cactus). Leaflike green stems, sometimes with prickles, and large flowers open during the day. The flowers are usually red though some hybrids are white. Each has several petals, and more flowers buds follow on the short flower stem. They are easy to grow, but require regular watering when in flower, usually spring/early summer. Zygocactus. Commonly called Christmas Cactus, as it produces large tubular red flowers freely during the winter. Stems are green and leaflike, frequently curving over the edge of the pot. It needs water and liquid fertiliser regularly when the flower buds form.
Very easy to grow
Notocactus. Green-brown ‘columns’, usually heavily covered with spines, which freely produce many-petalled flowers. One of the easiest Cacti to grow and very popular. Mammillaria. Large and easy to grow, with plants usually forming single circular clumps, occasionally producing small off shoots. One or two varieties are more columnear in shape but all produce rings of red, yellow or white flowers regularly each year. Lithops. Commonly called Stone or Pebble Plants, their greeny brown and white marked shapes are similar in size and contour. Usually they grow in clumps of white or yellow flowers. It is important to keep them dry during their ‘resting time’ from winter to early summer.
Echinocactus, Very spiny, tall, ribbed, circular plants, they produce flowers rarely when artificially cultivated, but are otherwise easy to grow. Best known is E. grusonii, with its golden yellow spines. A little lime added to the compost is beneficial. Chamaecereus. Attractive low growing plants with rounded prickly branched stems producing scarlet/orange tubular flowers each year. They should be handled with care as the stems are brittle, but they root from broken pieces. Kalenchoe. Easy to grow but they like richer and more moist compost than most cacti and succulents. They vary in height, but can grow up to 6 feet and produce .attractive leaves of green, grey or brown on short or long stems, according to variety. Flowers are usually red and borne in clusters.
Echeveria. Rosettes of multi-coloured leaves with a variety of shapes are produced at soil level or on stems several inches tall. The plants in this easy-growing group are as attractive out of flower as in bloom. The blossoms are usually a reddish colour. Euphorbia. The vast family of Euphor-biacea produces many types of plants as well as a few succulents. The latter are so varied in form as to be almost impossible to describe in general. They may be treelike, have leaf stems, be columnear, look like leaves, be very spiny, have some normal simple leaves, or produce single or clusters of flowers in various colours. Normal cacti and succulent growing conditions will suit them all.