Mösl Echeveria species will benefit from being grown outdoors during the summer as they are generally fast growers and can become straggly and somewhat etiolated if allowed to grow for too long indoors. The summer air and the generally rather lower temperatures help lo keep the plant compact and by ripening and hardening the surfaces of the plant they check growth and allow flowers to develop. During the winter they do nol need any great amount of warmth. 10'C (50°F) being quite warm enough for all the species, and during this time they are best kept on the dry side, watering on average once every four or five weeks. Plants may be grown easily from seed although in the case of commercial varieties these may not necessarily come true to type but cuttings are the easiest of all to lake. In order to lake cuttings a leaf should be broken off the parent plant and laid with its tapered end just covered by a little light loam, peat and sand compost. Within a very short period a small plantlct will form at ihe base of the leaf and when this is large enough to handle Ihe whole may be lifted and planted in a larger pot. The parent leaf will grow a little at first but as soon as ihe plantlct becomes established it is best to remove the larger leaf as it will otherwise take some of the strength out of the younger plant.
Echeveria glauca is one of Ihe more spectacular of the rosette-lype species and forms offsets readily, only very occasionally making a short stem. The rosettes have up
4 in (10 cm) or so. The leaves are rather more openly arranged than in the species illustrated on the previous page and are purplish in colour and very much more markedly spatulate. They are covered with a slight frosting and may have a reddish margin round the sides of the leaves, especially where the plant has been grown outdoors during the summer on a rock garden in full sunlight. The leaves are also much thinner than those of the iwo species on the previous page and the flower stems are much taller, often nearly a foot (30 cm) above the plant, with between twelve and twenty deep red flowers produced in the spring. There is also a variety E.g.pumila with longer, rather narrower leaves and yellowish flowers which have a little red near the base.
Echeveria pulvinata is at first a silvery plant but as it grows older il becomes more or less densely covered in brownish felt. Although included in the stcmlcss section it does ultimately make a short stem and may even form branches, however, il is nol a fast-growing species and rather more delicate than most. The rosettes are far less regular and compact than the other illustrated species.
Echeveria pilosa is another species which is frequently stemless when acquired but which develops a short stem with age. Like ihe illustrated species it is also covered with soft short white down but the leaves are very much more regularly arranged and are
Echeveria setosa has already been mentioned in connection with E.derenbergii with which il has been extensively hybri dized. Although the two species hydridize readily in cultivation they do not appear to hybridize readily in the wild. The rosettes of this species are characterized by the blunt dark green leaves covered with white bristly hairs on both sides. It is very free flowering, producing a succession of reddish-yellow blooms on short flowering stems that arise just off the centre of the plant between April and July. The seed germinates very readily, and this characteristic may have been a feature which prompted growers lo hybridize il.
There is also a hybrid between E. harmsii (syn. Oliveranihus elegans) and E. setosa called, appropriately enough. E. Set-Oliver. This has looser, neater rosettes and taller flower stems with rather larger flowers than the species.
Succulents with Upright, Arched or Hanging Stems
In the following section I have dealt with a variety of different succulents which are characterized by having upright, arched or hanging stems. Within this category there are. of course, many different families and no attempt has been made to impose a botanical order on the species illustrated, but they have been grouped by their superficial characteristics, with the plants with upright stems or trunks forming the first and larger part of the section and those with trailing stems coming towards the end of the section.
As the plants come from such a wide variety of families it is impossible to generalize about their cultural requirements and these are dealt with in detail under the individual varieties.
Aloes fall into two types in this classification. those with stems and those which do not form a true stem. The latter kind can be found on pages 175 and 176.
Aloe ferox requires a sunny situation as does the other commonly seen aloe of this type. A.arborescens. Once they become older they can be put outside during the summer provided that they are brought in before the first frosts and put out after the last ones. During the winter they should be kept on the dry side as excessive water can cause problems with rotting; in a greenhouse with cacti they can probably go all winter without water if kept cool, but in the home they will probably appreciate water once every six weeks or so. It is essential to give aloes an extremely well drained soil and it is recommended that extra sand is mixed into soil into which they are to be potted, and that the pot should be well crocked. A.arborescens comes from Natal where it forms a shrub. The bluish leaves develop a hard edge with teeth along the side and are curved and tapered in a very handsome way. A.arborescens flowers in winter but young plants are unlikely to produce flowers. A.ferox is widely distributed through South Africa and it tends to have more erect leaves than the previous species and the teeth are tinged slightly red. The flower stems of older plants have several branches on which the red hot poker-like clusters of flowers are produced. A characteristic feature of the species is the presence of spines down the rib at the base of the leaf and the occasional presence of spines on the upper surfaces too.
Haworthia reinwardtii is a very closely related species which, because of its ease of flowering and its comparatively slow growth, is an excellent plant to acquire at the start of a collection. Its cultural requirements are generally similar to the aloes just discussed but it will appreciate some shade in summer when it should not be allowed to dry out completely. Rosettes are formed at the base of the plant and these root readily; varieties may also be raised from seed but will seldom come true to type. There are very many recognized varieties of H. reinwardtii. the true species forms a stem up to 6in (15cm) in height round which the leaves are arranged densely in a tight spiral, the younger ones erect at first and flattening out with age. The upper surface has a few tubercles but the back is covered with fairly regularly spaced white tubercles which give the species its main attraction. Flowers arc produced fairly readily during the winter months and the resting period is the opposite from other cacti and should be given between June and September, Because they tolerate shade they can be used as a conventional house plant and do not need the very sunny position on the windowsill recommended
Crassula lycopodioides makes an excellent little pot plant. In south-west Africa it forms a small shrub under 10in (25cm) in height with very slender stems round which the numerous small green triangular leaves are arranged in a very regular square-shaped pattern. The flowers are almost microscopic and are produced deep down in the axils of the leaves. The plant may be easily propagated by cuttings which root readily and can be taken from any part of the stem.
live shape and great hardiness have encouraged growers to search for and propagate unusual forms. The most attractive form is undoubtedly the variegated C.I. variegata which has silvery leaves and again roots fairly readily as a cutting. C. /. num-slrosa has the leaves opened up like a comb at the top of the stem. It tends to revert quite readily to the true species and it is best to cut the true stems out as and when they appear to encourage the more interesting growth. There is also a form. C. I. pseudo lycopodioides, with much thicker stems than the true type and greyish-green leaves. An unusual feature of this variety is the way in which young shoots are produced from nearly all of the leaf axils. The cultivated specimens differ from the wild species in having fragile, more drooping stems with rather more open leaves; the true type with more densely packed leaves
Cotyledon undulata is a very distinctive species which is very common in cultivation and which can be readily raised from seed. Ultimately plants will grow to nearly 2 ft (60 cm) in height and the young shoots are covered with a dense white meal. The leaves, shaped a little like a scallop shell and markedly wavy at the edges, are produced opposite one another and like the young stems are also covered with a dense white flocking. This flocking is quite delicate and great care should be taken when applying insecticides to check whether or not they are harmful to grey-skinned cras-sulas and cotyledons, and if in doubt the general rule must be not to spray these plants with anything other than water. The flower stem is very long and carries a bunch of pendulous tubular orange-yellow flowers at the top throughout the late spring and
Crassula J'alcata is also frequently sold as Rochea falcata and is a native of South Africa. The leaves, like those of Cotyledon imdulata, are produced in opposite rows and are joined at the base where they clasp the stem. They may be propagated by cuttings or seeds, and flowers are regularly produced in the early part of the summer. It is quite a good idea to take the cuttings immediately after flowering as cuttings taken in this way and at this time will normally flower the following season. The grey-green coloration is susceptible to various insecticides as mentioned earlier and the flowers of this variety are a bright scarlet or occasionally orange-red. Some of the true rocheas are heavily scented, two of the best in this respect being R. coccinea which has a hyacinth-like smell and R.
They prefer a sandy soil and cuttings should be struck in a small pot or seed tray containing a mixture of half peat and half sand. As the plants develop and become ready for potting on, a little more loam can be added to give substance to the compost. A light feed with tomato fertilizer in the autumn together with regular pinching will cause them to flower profusely shortly after
Crassula perforata is easily recognized on account of the long trailing unbranched stems which are at first quite succulent but become harder with age. The leaves are perfoliate (which means that the stem appears to grow from the centre of the leaves) and sharply pinched at the tips. The general colour is grey-green but the leaf surfaces are densely covered with tiny red spots and fine grey hairs. Like some of the species described earlier they should not be sprayed unless professional advice has been sought first. The flowers are very small and are produced at the ends of the stems in late spring.
There are several other varieties of Crassula with perfoliate leaves; the one most commonly seen is C.rupestris, which also comes from Cape Province but whose leaves are generally smaller and fatter and whose stems branch rather more readily than those of C. perforata. For this reason it makes a bushier plant, but lacks the appeal of the tiny red spots on the leaves. C. brevifolia is typical of a group of slightly similar cras-sulas where the leaves have become so thick as to obscure the stems completely, the ultimate kind being probably C.arta which makes a sort of knobbly column.
Kalanchoes (the final 'e' is pronounced) are most commonly found in Madagascar, but some have crossed the Indian Ocean to naturalize themselves as far afield as China and Malaysia. Generally kalanchoes should be given a bright position on a sunny windowsill although if space is limited the smooth-leaved species, such as K.fedt-sclienkoi. K. daigremonliana and so forth, will tolerate a shadier position. They should be kept cool in winter and watered very sparingly. Plants are best propagated from cuttings or in certain cases by using the plantlets which develop round the edges of the leaves of some species.
Kalancltoe fedtschenkoi is a dense shrub with numerous erect branches which can become bowed down with age. The grey-green leaves are rounded with slightly crenellated edges. Flowers are produced on long terminal stems and are tubular and brownish in colour. The variegated form. K.f. marginata. although seldom producing a viable or attractive flower, has a splendid cream margin round the edge of the leaves which contrasts excellently with the red band on the very edge. It tends to outgrow itself easily so it is a good idea to prune it fairly rigorously as it looks very unsightly if allowed to develop long straggly stems from which many of the leaves have fallen.
Kalanchoe blossfeldiana can now be grown on a year-round basis using artificial blackout to simulate the winter conditions essential for flowering and as a result has become a popular house plant (see page 54). Very many hybrids have been raised recently ranging from red and pink to orange in colour. They require a rather peatier soil than the previous species and a mixture of equal parts of peat, sand and loam is probably the best. During the growing period it is a good idea to pinch the soft growing tips of the stems in order to encourage the formation of a bushy plant. The short-day treatment is relatively simple and involves artificial blacking out in summer for fifteen to twenty days so as to cut the day length down to 12} hours. The plants can then be grown on quite normally and flowers will be produced just over three months later. Generally the longer the dark treatment period the more profusely the plant will flower and the sooner the buds will be produced. Conversely if larger plants are required growing the plant in a brightly lit sitting or dining room during the winter will encourage it to develop leaves at the expense of flower buds. For the smaller collection there is a very attractive hybrid called Tom Thumb which remains fairly
Both Kalanchoe tubiflora and K.daigre-montiana are characterized by their ability to produce plantlets round the edges of the leaves. The former species is slightly less commonly seen than the latter and has slender upright stems, often attaining a height of 2 ft (60 cm) or more in cultivation, which carry numerous cylindrical leaves all round them. The leaves have a slight groove on the upper surface and are blotched or mottled in appearance. The adventitious buds (as they are technically known) or plantlets, appear at the end of the leaves furthest from the stem and soon develop miniature root systems even though they are still attached to the leaves. The flowering stem or inflorescence is produced at the end of the main stem of the plant during the winter months and the flowers hang from it on longish stalks. The flowers are reddish in colour but are not very attractive as they never open up to any extent. It is very rare for this particular species to branch and once the inflorescence has been produced in the second or third year it is normal for the plant to die back as it will have produced a good crop of plantlets by this time. Normally the plantlets will establish themselves round the base of the parent plant in the same pot but if it is wished to grow these plants in their own pots or to give some to a friend it is best to propagate plantlets cither by taking the entire leaf and laying it on a mixture of peat and sand, or alternatively by gently digging up some of the young plants established round the base of the parent plant and potting them up individually in small pots.
Kalanchoe daigremontiana is, like the preceding species, a native of Madagascar, where it forms a rather more robust plant than K. tubiflora up to 3 ft (1 m) in height. The stems are normally unbranched and are brownish in colour supporting broadly triangular leaves which fall off with age. The adventitious buds are formed in very large numbers along the wavy edges of these leaves and it is not uncommon for these plantlets to start growing while still attached to the parent leaf and to produce their own young plantlets in turn. The upper surfaces of the pale green leaves arc normally flat, but if they are allowed to become too cool in winter, small depressions can be formed on them; however, these in no way detract from the growth of the plant which will continue unchecked when heat is restored. The flowers are considerably more ornamental than those of K. tubiflora; not only do they open up a little more, but they are also carried on shorter stems in a slightly more tightly grouped cluster. It makes an ideal plant for children who will be fascinated by the large numbers of plant-lets produced and it can safely be put outside during the summer, this will also help to keep the growth fairly short and prevent the plant becoming unmanageable.
Kalanchoe beharensis is not a very common plant, partly because it is comparatively slow growing for a kalanchoe and partly because it attains a fair size. However its appearance is most impressive. The stems can reach a height of 4 ft (1 -25 m) or more and although they are smooth towards the base they are covered with a dense sur rounding of woolly hairs near the top of the stem. The leaves have very wavy edges and like the upper parts of the stem are densely covered in brown woolly hairs which give the plant the appearance of being slightly rusted. Flowers are only produced on older specimens and the plant tends to shed- most of its lower leaves in cultivation. It is possible. however, to cut the upper part of the stem off neatly and to root it in some fresh well drained compost and so make a more dwarf and attractive plant out of the old straggly one. Moreover, the part that remains in the pot below the cut will, in all probability, sprout again and provide a fresh source of cutting material for future
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