Siberian Columbine in rocky place.
Wall Cress, Arabis.—Dwarf alpine plants, spreading in habit, and generally producing myriads of white flowers, exceedingly suitable for the decoration of sandy or rocky ground, where the vegetation is very dwarf. With them may be associated Cardamine trifolia and Thlaspi latifolium, which resemble the Arabises in habit and flowers. All these are particularly suited for association with the purple Aubrietias, or yellow Alyssums, and in bare and rocky or gravelly places, old walls, sunk fences, etc.
Sandwort, Arenaria.—A most important family of plants for the wild garden, though perhaps less so for lowland gardens where more vigorous types flourish. There are, however, certain species that are vigorous and indispensable, such as A. montana and A. graminifolia. The smaller alpine species are charming for rocky places, and the little creeping A. balearica has quite a peculiar value, inasmuch as moist rocks or stones suffice for its support. It covers such surfaces with a close carpet of green, dotted with numerous star–like flowers. Some of the smaller species, such as Arenaria cæspitosa (Sagina glabra var.), better known as Spergula pilifera, might be grown in the gravel, and even used to convert bare and sandy places into carpets of Mossy turf. In certain positions in large gardens it would be an improvement to allow the very walks or drives to become covered with very dwarf plants—plants which could be walked upon with little injury. The surface would be dry enough, being drained below, and would be more agreeable to the feet. Removing any coarse weeds that established themselves would be much easier than the continual hoeing and scraping required to keep the walk bare. Of course this only refers to walks in rough or picturesque places—the wild garden and the like—in which formal bare walks are somewhat out of place.[ill127]
Tall Asphodel in copse.
Asphodel, Asphodelus.—The Asphodels are among the plants that have never been popular in the mixed border, nor are they likely to be so, the habit of the species being somewhat coarse and the flowering period not long, and yet they are of a stately and distinct order of beauty, which well deserves to be represented in open spaces, in shrubberies, or on their outer fringes. The plants are mostly natives of the countries round the Mediterranean, and thrive freely in ordinary soils.
Lords and Ladies, Arum.—Mostly a tropical and sub–tropical family, some of which grow as far north as southern Europe. These are quite hardy in our gardens. The Italian Arum is well worthy of a place in the wild garden, from its fine foliage in winter. It should be placed in sheltered half–shady places where it would not suffer much from storms. The old Dragon plant (A. Dracontium) grows freely enough about the foot of rocks or walls in sandy, or dry, peaty places. The nearly allied Arum Lily (Calla æthiopica) is quite hardy as a water and water–side plant in the southern counties of England and Ireland.
Silkweed, Asclepias.—Usually vigorous perennials, with very curious and ornamental flowers, common in fields and on river banks in North America and Canada, where they sometimes become troublesome weeds. Of the species in cultivation, A. Cornuti and A. Douglasi could be naturalised easily in rich deep soil in wild places. The showy and dwarfer Asclepias tuberosa requires very warm sand soils to flower as well as in its own dry hills and fields. A good many of the hardy species are not introduced; for such the place is the wild garden. Some of them are water–side plants, such as A. incarnata, the Swamp Silkweed of the United States.
Starwort, Aster.—A very large family of usually vigorous, often showy, and sometimes beautiful perennials, mostly with bluish or white flowers, chiefly natives of North America. Many of these, of an inferior order of beauty, used to be planted in our mixed borders, which they very much helped to bring into discredit, and they form a very good example of a class of plants for which the true place is the copse, or rough and half–cared–for places in shrubberies and copses, and by wood–walks, where they will grow as freely as any native weeds, and in many cases prove highly attractive in late summer and autumn. Such kinds as A. pyrensæus, Amellus, and turbinellus, are amongst the most ornamental perennials we have. With the Asters may be grouped the Galatellas, the Vernonias, and also the handsome and rather dwarf Erigeron speciosus, which, however, not being so tall, could not fight its way among such coarse vegetation as that in which the Asters may be grown. Associated with the Golden Rods (Solidago)—also common plants of the American woods and copses—the best of the Asters or Michaelmas Daisies will form a very interesting aspect of vegetation. It is that one sees in American woods in late summer and autumn when the Golden Rods and Asters are seen in bloom together. It is one of numerous aspects of the vegetation of other countries which the “wild garden” will make possible in gardens. To produce such effects the plants must, of course, be planted in some quantity in one part of a rather open wood, and not repeated all over the place or mixed up with many other things. Nearly 200 species are known, about 150 of which form part of the rich vegetation of North America. These fine plants inhabit that great continent, from Mexico—where a few are found—to the United States and Canada, where they abound, and even up to the regions altogether arctic of that quarter of the world.