Perhaps the St. John’s worts come next to ivy and ferns in their usefulness for planting under trees, as they are always decorative, being ever-green. In the spring, the foliage is a most lovely soft apple-green, and in summer when the golden cups filled with anthers issue forth from the axils of the leaves, the effect is beautiful. Hypericum calycinum is the Latin term for these plants, and though they will do on the dryest bank and in the poorest soil, being very tough and wiry, if they are grown in good loam and manure is occasionally given them, they will repay with far finer flowers, which will be produced for a longer season.
A good breadth of woodruff makes a very pretty picture for several weeks, and has a delightful scent; here and there bulbs can be planted amongst it, neither being harmed by this plan. The aubrietias flower with unfailing regularity under trees, even when the aspect is north, and no gleam of sunshine reaches them; their greyish-green rosettes resist drought splendidly, and though these plants do not give us so much blossom in unfavourable positions, still they make a very pretty show. Aubrietias can be easily propagated by division; every morsel grows.
BANKS UNDER TREES. The white arabis also does well under similar conditions; both are useful for draping perpendicular surfaces, such as the steep side of a bank or hedge. A raised border, with facing of bricks, is rather a nice way of growing plants under trees, and the work of tending them is pleasant, less stooping being required.
The mossy saxifrage droops over the edges, and mingles well with the arabis, but it must be more carefully watered, as it is apt to die out; pieces should constantly be taken off, and dibbled in so as to fill up any gaps. The periwinkles meander charmingly over the roughest stones, and in the most dreary spots; their glossy ever-green leaves, and fresh bright little flowerets always looking cheerful whatever the weather. They creep quickly, rooting every few inches as they grow; on the perpendicular face of the rock, succulent plants like echeverias can sometimes be made to grow (those little green rosettes, having each leaf tipped with red, which can be bought so readily in May for about twopence each).
Many things will do for a time, that want renewing each year, even if hardy. Cowslips, primroses, polyanthus, wallflowers, all will make a fair show if planted out just before flowering, but, unless a few hours’ sun daily shines on them, they will not retain enough vitality to produce seed, and being biennial soon die out, leaving not a trace behind.
A great many bulbs do admirably under deciduous trees, especially those which blossom before the new leaves on the branches above them have reached any appreciable size.
Scillas bloom in the same place year after year; snowdrops also do fairly well, and lilies of the valley ring out a few of their dainty bells every spring (a rich vegetable soil suits them best). Tulips only do well when planted afresh every autumn; but, as they are so cheap, that is not a great matter. The megaseas, mentioned in another chapter, give forth many of their fine leaves, but they refuse to turn colour, owing to the want of sun. Fox-gloves, also, grow and flower, seeming to enjoy their position.
If the aspect of the space to be filled is a cold one, such things as geraniums will only give a few poor flowers, and then succumb. Even pansies wilt and gradually fade away under trees, for their soft, weak stems and leaves soon get drawn up for want of light, though they will do well enough on an open border, facing north.
Hard-wooded plants will be generally found to do best; indeed, some of the shrub tribe succeed very well, particularly barberry, pernettyas, the early daphnes, whortleberries, gaultheria shallon and cotoneaster.
While on the subject of shrubs, it may be as well to mention several attractive kinds which may be planted in place of the eternal box and Portugal laurel; of course, these two have almost every good quality; they will do in any soil, are ever-green, and resist smoke, dust and dirt well; but, in places where poor soil and a soot-laden atmosphere are absent, substitutes might occasionally be found for those shrubs, which will have the added charm of novelty. One of the nicest for small gardens is cotoneaster microphylla; this is a joy to look at, all through the winter months, when it is at its best; the branches grow in an uncommon manner, and are of somewhat prostrate habit; they are thickly clothed with dark, small leaves the whole way up the stem, and shining amongst them are the pretty crimson, almost transparent berries. It is quite distinct from the ordinary berry-bearing shrubs, as there is nothing stiff about its gracefully-curving sprays, which look well cut and wedged in the Japanese fashion. Shrubs of this variety may be had as low as sixpence, but it is better policy to get a larger one, costing about eighteen pence, as they will sooner be of a presentable size; they are shrubs, too, that do not altogether show their capabilities when at a very youthful stage.