Cactus plants, which include the fascinating bizarre cacti, are to be considered as the most specialized of all plant groups. Since they live chiefly in areas typically hot and dry they assume fantastic forms which enable them to survive in such regions of adverse conditions. The grotesque growths tend to conserve water and reduce transpiration. In the case of the cacti, leaves are dispensed with almost entirely and the stems take over the functions which the leaves on non-succulent plants perform. In the mimicry plants (stemless mesembryanthemums) the leaves have entirely lost their semblance and appear as chubby, squat conical-to-spherical plant-bodies.
The root systems of succulent plants are hardly extensive or penetrate the soil very deeply. Usually they lie just below the soil surface which enables them to make quick use of any moisture that may come their way. Thus the plants are able to store water in special tissues and rely on it when water is scarce. For this reason, they are known as “succulents” which literally means “juicy plants.”
Since succulents have learned to adapt them-selves so nicely to adverse conditions we can readily see why they make such good houseplants. Where other plants fail in the hot dry atmosphere of our living rooms, the succulents usually succeed and impart a bit of greenery the year round. People often kill succulents by kindness when they pamper them too much. However, it is wrong to believe that succulents need no attention whatsoever.
Succulents are numbered in at least 20 different plant families. There are hundreds to choose from in all imaginable shapes and forms. If only a windowsill is available it can be utilized and made attractive with these plants. It is to be remembered that succulents require lots of light; if grown in the absence of it, the plants will exhibit scrawny etiolated growth which will be more readily subject to insect attacks and plant diseases. Sun porches afford more room where more elaborate set-ups or staging can be maintained. However, if one can afford a greenhouse, no matter how small, succulents can be grown to perfection without too much fuss.
A fact to remember is to choose the container best suited for use in the home, if that is the only available location. Succulents look very attractive in glazed pottery, but care in watering must be exercised since such containers do not dry out as fast as ordinary flower pots. Small pots can be set in a large tray or metal box filled with sand, gravel or sphagnum moss, and kept moist. Frequent repotting is not necessary.
Where space is at a premium more satisfaction will be derived if the grower concentrates on a few individual groups than on a general collection.
Succulents usually can be propagated from seed, offsets and cuttings, and by grafting. It is true that growing them from seed will require patience, especially in the case of slow-growing cacti, but on the whole many succulents will produce good growth quickly. All you need is a flower pot or seed flat (a cigar box will do), a piece of glass for cover, good porous soil, and a package of fresh seed. Seeds may be sown anytime in the year if high temperatures can be maintained, as in greenhouses, but perhaps in the average home seed-sowing should be carried on in spring and summer. A uniform temperature of 70° F. should be provided and the seed pans placed in a window with a southern exposure, where light is always available. The soil in the seed containers must never be allowed to dry out, and seed must not be planted deep—just barely covered with sand or fine gravel. Water can be applied with a fine syringe or in the case of pots, the pots watered from below by placing them in a pan of water. Generally a glass cover is placed over the box or pot to aid in conserving moisture and heat, but the glass should be painted to shade the seedlings as they appear and gradually removed so that seedlings will get accustomed to the light. Supply ventilation to the seedlings by raising the glass cover occasionally so that damping-off does not occur. Seedlings need not be transplanted until they have become large enough or when they begin to crowd each other.
Most succulents can be multiplied by off-shoots which usually appear at the base of the mother plant or anywhere along the stems. Cuttings can be made almost anywhere—from tips, lateral branches, from leaves, and in many cases just tiny fragments of portions of stems such as ribs and tubercles of cacti. Cuttings generally root easily and produce a mature plant more quickly than seedlings. When making cuttings use a clean sharp knife or razor blade. Heal the cutting in a dry, shaded place until a skin or callus is formed; the time will vary with the species from one week to a month or more, depending on the size of the cut. The wider the cut the longer it will require to heal over. Cuttings can be rooted in a mixture of sand and soil but more preferably in pure sand or vermiculite, and as soon as roots form the rooted plants can be planted in the regular way. As a precaution, do not keep the rooting medium too wet from the beginning as rot may set in and spoil your effort. In that case, the cutting will have to be cut back to healthy tissue and calloused over.
Cacti and spurges are usually grafted in order to speed maturity of these plants. There are other reasons, too, such as to save a plant when only a small piece is available which would not easily make a cutting, or to develop more decorative and bushy plants, and to raise varieties that are considered difficult to grow on their own root. Still another reason is to preserve abnormal forms such as crests and monstrosities which are greatly sought by connoisseurs.
Although it is possible to graft other succulents besides the cacti, like spurges and stapeliads, there is really no point gained. Before attempting grafting remember that only related plants can be grafted. A Spurge cannot be grafted onto a Cactus or vice-versa—only species within their respective families.
There are 3 kinds of grafts commonly employed—the cleft, the flat and the side. All thin-stemmed plants are suitable for cleft-grafting while the thick and globose types require a flat graft. The side-graft is usually employed on thin-stemmed plants although it can be used with success on the chubby kinds too. In cleft-grafting the stock (the rooted plant upon which the scion will be placed) is cut back to a desired height, depending on what effect is desired for the plant later on. The Christmas Cactus, which bears pendent stems, naturally would look more effective grafted on a stock at least 6-12 in. tall. A slit is made at the top of the stock about an inch deep. The stem of the scion is then cut on 2 sides to form a wedge and inserted into the split of the stock. Firm the graft into the desired position and run a cactus spine or two through the united portions; then wrap some cord or raffia around the graft, just taut enough to hold the scion in place but not so tight as to cut into the stock.
In the flat graft, both scion and stock should be of approximately the same width at the intended union. After selecting the 2 plants, make a smooth transverse cut on each specimen and then place the scion on the severed stock, pressing the 2 flat surfaces firmly together. The scion can be held in place with 2 large-sized bands or string run over the top of the scion and underneath the flower pot, or by the use of flexible wire bent in “U” shape.
The side graft requires no special operation beyond slicing one side of both scion and stock and holding the 2 joints in place. When grafting operations are completed, set the plants in a warm shaded place so that the cut surfaces will not dry out too rapidly, preventing perfect unions. Inspect all grafts regularly each day to note whether union has formed properly. After grafted plants have become established only normal care is necessary.
The most popular members of the Cactus Family are the mammillarias, better known as “pincushion” or “nipple” cacti. They are mostly small globular to cylindrical plant-bodies covered with nipple like tubercles with clusters of spines on their tips where the areoles appear. The small bell-shaped flowers appear as a crown on top of the plant and in some species a circle of colorful scarlet-to-crimson fruits will develop simultaneously.
There are over 300 different kinds described and every one is a gem, but the most popular are those which bear colorful descriptive names such as the Old Lady, Powder Puff, Bird Nest, Feather Ball, Ladyfingers, Thimble, Snowball, Fishhook and Golden Stars. They can be readily supplied by Calif. nurserymen who grow them by the thousands.