Rockery Plants

The rock garden is full of interest in spring, and now is the time to go over it carefully, restricting here, propagating there, making additions both of stones and plants. One of my own rockeries is neither more nor less than a nearly perpendicular loose stone wall, which was put up to sustain the soil of a "cutting." I recall the debates as to the best plan of dealing with the cutting when it was first made. Should it be "battered" at an obtuse angle, and turfed? Should it be covered with shrubs? Or should it be faced with rock? An intelligent builder turned the scale; and here let me say, out of gratitude, that builders are not at all such terrible Vandals as they are supposed to be, nor do they hate gardens with the virulence which is accredited to them. They really have souls, and are by no means devoid of a sense of beauty. A great deal of the harm that they do they cannot help. It is a necessity of their work that ground should be cut up, and stacks of bricks built, and the place sown with mortar morasses. I am convinced that they often feel really sad when, in the addition of a new wing to the house, they spoil a pretty garden corner.

I mention my rock wall because it may convey a useful suggestion to others. It has done many degrees better than I ever expected that it would. To begin with, the soil of the bank was very poor, near chalk. Then, the angle being acute, very little rain could beat in. According to all the canons of rock-plant culture, a failure was to be expected. Nothing of the kind has happened. Nearly all of the sixty or seventy kinds put in have established themselves, and some have spread a good deal. The stone used is a fairly hard Kentish "rag." This is not an ideal stone, but the quality of the metal varies in different quarries, and I appear to have struck a good vein. One thing in favour of rag is that plants like it. It is a limestone, and they appear to enjoy getting their roots down to the base of the pieces. Of course, there is a good thickness of soil at the back of the plants, and although the crevices between the stones are small, the plants have a deep rooting area, such as it is.

The liking which many plants have for lime induces me to wonder how far we may expect chalk or limestone to compensate for what we call "poor" soil. I call my thin soil over soft chalk poor, because it lacks humus, and fruit and most vegetables grow with very little vigour in it. But soil that is poor for fruit and vegetables is apparently by no means poor from the standpoint of low-growing plants. They do not require so much humus, nor so much moisture, as plants with much expanse of leafage. I make these remarks in full cognisance of the orthodox advice (which I have repeated myself before now) that rock plants should have a liberal allowance of fibrous loam. They certainly need it in a rockery, where the soil has to be made up, but apparently not so much in a bank, where there is considerable "back run" for their roots.

The lover of rock plants who looks them over in spring with a view to propagation sees that they differ a good deal in their habit of growth. Some of the clumps consist of a series of shoots springing separately from the soil, almost like a Michaelmas Daisy. It is obvious that these may be increased by division. Parts of the clump may be cut away, and pressed into the crevices which are bare. In rock walls "planting" in the ordinary sense is impossible, and one could hardly expect a plant that had so insecure a hold to thrive. But with a good squeeze in, and a handful of moist earth pressed after them, they manage to retain their place, and soon anchor themselves securely with their own roots. One odd bit so thrust in developed in such an astonishing way on my wall, that it attracted the attention of a pair of wagtails, who regarded it as splendid cover. Any way, they found a comfortable ledge under its long streamers, built a nest, and reared a brood. Some rock plants are not easily propagated by division, because the growth (and it may form a considerable mass) is found to depend from one long tough stem. Cuttings or seeds must be resorted to in these cases.

The following are good plants for rockeries:

Spring Bloomers

Alyssum Saxatile Compactum.

American Cowslips.

Anemones, dwarf kinds.

Antennaria.

Arabis, single and double.

Aubrietia, various colours.

Cerastium.

Dianthus (Alpine Pinks).

Dog's-Tooth Violets.

Edelweiss.

Gentians.

Iberis (Perennial Candytuft).

Irises, dwarf kinds.

Narcissus, small kinds.

Omphalodes Verna.

Phloxes, dwarf kinds.

Primulas.

Saxifrages, many kinds.

Soldanella Alpina.

Summer Bloomers

Acaena.

Achilleas.

Androsaces, several species.

Arenaria Balearica.

Aster, dwarf Alpine.

Campanulas, dwarf kinds.

Convolvulus Mauritanicus.

Dianthus, several species Geraniums, hardy Helianthemums (Sun Roses) Lithospermum Prostratum Onosma Tauricum Poppies, Iceland Primulas, various kinds Summer Bloomers.

Saxifraga Hypnoides „ Longifolia Sedums (Stonecrops)

Sempervivums (Houseleeks).

Silenes.

Veronicas.

Various bulbs, such as Colchicums, Crocuses, Cyclamens, Irises, and Snowdrops, will give bloom in autumn and winter.