Almost before spade is put to ground, certainly before any attempt is made to plan a garden in detail, one must have some idea of the plants with which one is going to work. There are tens of thousands of different kinds and one can spend a lifetime studying them in detail if one feels so inclined, but a much simpler, broader view will be quite sufficient to enable an attractive and satisfying garden to be made.
First one must learn to distinguish between hardy, half-hardy and tender plants. Hardy plants are those that can be grown outdoors throughout the year in the locality in which the garden is to be made. Naturally enough the list will vary with the climate. The extreme south-west of England and the south of Ireland are almost as mild in winter as the French Riviera, and it is possible there to grow plants that would die of cold in the north or east of Britain. But the great majority of plants that are sold as being hardy can really be planted outdoors and left outdoors without protection in most parts of the British Isles.
Tender plants are those which, in the locality under discussion, need protection all, or at least most of, the time. They are plants for greenhouses and conservatories, or to be grown in rooms that are adequately heated in winter.
Between these two majorare half-hardy plants, which need protection in winter but can be grown outdoors in summer. They include some very popular plants. Such as the dahlia and the geranium, but in general they involve the gardener in more work and require a greater degree of understanding than hardy plants.
The next big division is into. Biennials and perennials.
Annuals must be grown afresh fromevery year. They develop very quickly, start to flower within a few months (some within a few weeks) of being sown, but rapidly complete their life cycle and die. Many of them can be produced very cheaply and they are admirable for a quick and for filling in gaps, but a garden that relies too heavily on annuals is likely to fluctuate greatly in its degree of interest and beauty. For a few weeks in summer it may be a blaze of colour and yet have little to offer at other seasons.
Hardy annuals are those that can be sown outdoors where they are to grow and flower. Half-hardy annuals must be raised under glass, either in aor frame, but later on, as the weather gets warmer. They can be planted outdoors to flower. In some fairly mild places it is possible to half-hardy annuals outdoors in late spring. Tender annuals are raised and grown under glass.
Biennials resemble annuals in needing to be raised anew fromeach year, but they differ in taking more than one year to complete their growth cycle. sown one year will give the following year, after which the plants produce seed and die.
Perennials are plants that go on living for many years. Some will live longer than others, an oak tree for hundreds of years, a lupin probably only for four or five years, but both, in gardening terms, are perennials. They are the plants that give permanence to the garden and, if wisely chosen, they are the plants that involve the gardener in least labour.
Perennials are of two major kinds, herbaceous and woody. Herbaceous peren-nials have comparatively soft growth and many, though by no means all, die back to ground level each autumn and then grow up again in the spring. Woody plants, by contrast, make a permanent framework of growth. They are the plants we know as trees and shrubs, and because theirand branches, and sometimes their , are there in the winter just as much as in the summer, they play a particularly important part in the garden.
Herbaceous perennials, like all the other, may be divided into hardy, half hardy and tender, with all the differences which these distinctions make to cultivation. Hardy herbaceous perennials are amongst the easiest plants to grow, and it is almost certain that some will be used in every garden.
Bulbs, Cornis and Tubers
Bulbs, corms and tubers are really herbaceous plants in that they are perennials and have soft growth. But gardeners tend to think of them separately, partly because many of them do need different treatment, partly because they tend to be commercially grown and sold by different people. Bulb growing is a big industry on its own and since many bulbs can be left out of the ground for long periods, they fit in very well with shop trade and are sold in great quantities by many shopkeepers who would hesitate to handle plants that had to be kept moist and in soil.
Rock plants, too, are very largely herbaceous plants, though some are small shrubs. But again gardeners tend to think of them separately because of their different use in the garden and the fact that they are usually offered in separate trade catalogues, often prepared by firms which grow nothing but rock plants. Their peculiar characteristic is that they are small and suitable for growing in rock gardens or on walls, but many of them have other uses as well.
Aquatics, or water plants, are also herbaceous plants, but they are in-variably kept in a separate category because of their very special requirements. There are nurseries that specialize in them and issue catalogues devoted to them. These are the plants to be grown inand in slow moving water. Few of them will survive in swift flowing streams.
Shrubs are an immensely important group to the gardener, for they provide much of the best material for giving permanence and solidity to the garden scene. They are divided into deciduous and evergreen categories, the former losing theirin autumn and growing a fresh lot the following spring, whereas the evergreens retain their leaves throughout the winter.
Trees, too, can be either deciduous or evergreen, and are distinguished from shrubs mainly by their greater size. It is, in fact, often impossible to determine precisely whether a given woody plant should be considered as a shrub or a tree. A cypress, for example, clipped as a hedge, would reasonably be called a shrub, whereas precisely the same plant allowed to grow naturally to its full size, which might be 50 or 60 ft (15 to 18 m) high, would certainly be a tree. A tree need not necessarily have a bare main trunk with branches on top. Such trees are referred to as standards and when a tree branches right from ground level it is sometimes referred to as ‘skirted’. Trees, like shrubs, give the permanent framework to a garden. Even more than shrubs they can provide the dramatic points of interest but they must be used with discretion because of their ultimate size. Too many trees, or badly chosen trees, may eventually completely obscure a garden and make it difficult to grow anything else.
are shrubs but they have been so highly developed by gardeners that they tend to be grown by specialist nurserymen and to appear in separate catalogues. Certainly in the garden they are often used in a diflerent manner from most other shrubs.