On the whole pileas are small, compact plants which will all benefit from having their growing tips removed periodically in order to induce a more bushy appearance. They are also what we might term expendable plants, in that it is often better to make new plants every year or so and dispose of the older parents which lose their shape and attraction if kept for too long.

Cuttings a few inches in length root very easily in standard house plant compost if placed in a warm propagating unit, several cuttings to each pot. When they have rooted and obviously begun to grow the growing points of each cutting should he removed. Grown in moderate light in a warm place they will give little trouble. Feed with a weak liquid fertiliser while in active growth.

Water freely when in active growth and moderately at other times; if suggested temperatures cannot be maintained during the winter months plants will fare better if the compost is kept on the dry side. This advice applies to almost all plants grown in the greenhouse, garden room or indoors.

If a small-leaved, quick-growing plant is required this could well be the one. The cream- variegated leaves are roughly triangular in shape, and the plant has a natural clinging habit which will take it to the ceiling in a very short space of time. “Iso prevent growth becoming too long and thin it is wise to provide some form of trellis support round which the plant can be twined.

The variegated form Sasifraga sarinentosa tricolor is much less vigorous, requiring more careful handling, and will certainly need the higher temperatures indicated above. It will also do better if confined to small pots, as growth is not sufficiently active to justify planting them in hanging baskets as suggested above for the green form.

As small plants Schefflera digiutia and its Australian relative Schefflera actinophyllo are not particularly exciting, but as mature specimens there are few plants with purely green foliage which can match them for elegance. They are easy to manage in light, airy conditions. New plants are usually raised from seed, but hard wood of older plants that have become leggy and unattractive is not difficult to propagate in reasonable conditions.

Not all the bizarre orchid flowers appear in miniature. Among the larger flowering varieties can be found some very curious flowers and methods of flowering. The genus Stanhopea is known for its highly individually styled flowers. In all the species the petals and sepals are drawn or folded back to totally expose the lip.

Pseudobulbs (or false bulbs) are so called because they do not grow under the ground, and unlike the true bulb of an onion the pseudobulb is more like a potato (below). Pscudobulbs are swollen stems which hold the reserves of moisture for the plant and enable it to withstand quite severe periods of drought.

Some may be covered on the outside by the bracts which carry the leaves; others will be perfectly clean from bracts and are green and fresh-looking for many years; others have a protective bract which will remain green until the pseudobulb has matured, when the bract shrivels and dies.

Grown from seed or cuttings, these are useful and colourful plants which will flower for many months of the year in the garden room. Seed is sown in February-March in the conventional manner in well-moistened compost.

The reason for keeping the compost only just moist in winter is that wet compost allied to low temperatures can be especially harmful to many indoor plants, and the stephanotis is no exception.

There is also a white form of this plant which is equally easy to care for. In recent years a number of hybrids have also been developed and there is now a wide colour range to choose from. A lightly shaded position which is also cool and airy should be provided. Feed regularly during the spring and summer and pot on vigorous plants annually using a standard house plant compost which is not too heavy; that is, with a reasonable amount of peat in its make up to prevent it becoming compacted.

These tropical forest plants require a warm, humid atmosphere, but should not be too wet at their roots, so a well-drained compost is essential. To encourage drainage a 2-in. layer of crocks should be placed in the bottom of the pot before introducing the compost, which should he of a peaty nature.

Small, star-shaped flowers are produced in profusion in winter, and there are numerous colours, of which the rose pink is probably best. New plants may be raised from seed sown in good heat in March, or by means of cuttings which root very easily at almost any time of the year if reasonable heat is available, somewhere in the order of 21C. (70F.).

Besides being useful indoor plants they are equally attractive when hardened off and planted out in the garden in the centre of wide beds of annual flowers.

African Violet must surely be the most popular flowering pot plant in the world today. The poinsettia and pot chrysanthemum growers may dispute this statement, but when you consider the vast numbers of African violets which are produced in small pots throughout the year there seems little doubt that they are miles ahead of the poinsettias and chrysanthemums which demand much larger pots as a rule, and so require very much more greenhouse space than the saintpaulia in which to grow.

These members of the Araceae family provide us with many fine green plants with leaves of an infinite variety of shapes much sought after by those wanting plants with an architectural appearance.

All of those suitable for pot culture can be raised from cuttings taken in autumn or spring, though autumn cuttings taken after plants have flowered is advised as they get off to a much better start for the new season. Cuttings about 4 in. in length should be removed and allowed to dry for twenty four hours before they are inserted in sandy compost.

Most will tolerate temperatures as low as the 13′C. given above provided plants are kept on the dry side and lower temperatures apply for only short periods. Some years ago we were amazed to find that during a particularly cold winter Philodendron bipinnatilidum survived in temperatures that dropped as low as freezing point ; compost was kept very much on the dry side. However, one would not recommend such low temperatures as the plants will just about survive and take a considerable time to recover.

If a small-leaved, quick-growing plant is required this could well be the one. The cream- variegated leaves are roughly triangular in shape, and the plant has a natural clinging habit which will take it to the ceiling in a very short space of time. “Iso prevent growth becoming too long and thin it is wise to provide some form of trellis support round which the plant can be twined.

Leaves are fleshy to the touch, but otherwise resemble those of the smaller hederas, and many is the time we have had flower show visitors come up and whisper that we have made a mistake with one of our labels, only to be assured in an equally low whisper that it isn’t an ivy!

Propagation is by division of the roots, and can be done at almost any time while the plants are not in flower, but preferably in the spring of the year so that the divided pieces can benefit from the more agreeable growing conditions prevailing. For the initial period following division the young plants should be put in small pots filled with a compost composed almost entirely of fresh sphagnum peat.

One adaption in orchids can be found among the epidendrums. The species E. falcatum retains all its weight in the thick, heavy leaves. The root system is not numerous, but s-ong enough to hold a heavy plant firmly in its place on a tree. The pseudobulbs are merely short stems which support the long, spears-lriaped leaves which, rough and hard, will withstand a harsh environment. They are the main source of food supply for the plant.

The life span of a root can be one season only in orchids whose pseudobulhs arc of annual duration or the roots may live for several years, their life span related to the state of the pseudobulbs they are supporting. When leaves are eventually shed, that pseudobulb has no further use for roots, and they will die naturally.

On dormant roots the growing tip ceases and is completely covered by the velamen. These roots will recommence to grow at the start of the next growing season. Roots can be killed when a plant is being persisently overwatered, or is left standing in water.

Although a humidifex will greatly assist in keeping up the humidity, particularly during the summer months when the humidity is lost through the open ventilators, it is nevertheless no substitute for manual damping-down, which should also be done whenever possible. One humidifex such as illustrated would be sufficient for a To x 8 ft (3 x 2.5 m) greenhouse, or one room indoors.

It should be placed near the floor, below the plants, to allow the cool vapour to reach the plants standing above. Within a few weeks of introducing a humidifex into the greenhouse or home you should see a noticeable increase in aerial root activity on your orchids.

All this has a beneficial effect on the epiphytes which can take up food and moisture through aerial roots and leaves, thus sustaining a healthy plant far above the ground. Maintaining this atmosphere in the orchid house requires regular damping-down and spraying of floors, staging and pathways every day, or even several times a day in hot sunny weather.

The lycastes are a relatively small, but influential, natural genus of medium-size plants. They have had a great impact on the related anguloas with which they will readily interbreed to produce some of the most showy artificial hybrids.

While some species, such as Masdevallia coccinea, produce some of the most vibrant colours in the orchid flora, others are very drab. Of the 300 or so species, many are in cultivation alongside a small number of hybrids. The flowers are characterized by the triangular shape of the large, spreading sepals, of which some (such as those of Masdevallia caudata) have extended “tails”. The petals and lip are much reduced and remain generally hidden at the centre of the bloom. In other species, such as M. racemosa, the sepals are fused at the base to create a tube that contains the diminutive other segments. While M. veitchiana is outstanding for its vibrant orange and red colouring, others, such as M. ventricularia, which has curious brown-spotted, tubular flowers, are nonetheless interesting and worth considering.