The Houseleeks (Sempervivum)

The Houseleeks (Sempervivum) are greatly valued for the rockery. Arachnoideum, the Cobweb Houseleek, rosy flowers in summer, is one of the best known.

Senecio Macrophyllus

Senecio Macrophyllus is a particularly fine species of Groundsel, with broad leaves, and large corymbs of yellow flowers, which are produced in late summer.

Two or three of the Catchflies (Silene) are charming perennial plants, notably Acaulis, very dwarf, rosy flowers, a spring and summer bloomer well suited to the rockery; Schafta, rose, dwarf, a summer bloomer; and Alpestris (Alpine Catchfly), white, dwarf, flowering in late spring and early summer.

The Moonwort (Soldanella Alpina)

The Moonwort (Soldanella Alpina) with pretty fringed violet flowers in spring, is a suitable plant for the rockery.

The Golden Rods (Solidago)

The Golden Rods (Solidago) are tall, late blooming plants, with dense spikes of yellow flowers.

The Sea Lavenders (Statice)

The Sea Lavenders (Statice) are popular on account of their graceful habit and charming shades of colour. Incana Hybrida, which varies from pink to blue, blooms in summer, and grows about a foot high; Latifolia, lavender, a summer bloomer, two to three feet high; and Suworowi, rosy purple, one foot, summer bloomer, are all very desirable plants.

Brompton Stocks

Brompton Stocks are among the most popular of hardy biennials. Sown in summer, thinned, and planted out in autumn, they will form beautiful breaks of colour in spring. They can be bought in separate colours, such as yellow, flesh, rose, crimson, white, carmine, blue, and violet, if desired, or in mixture. The popularity of the Ten-week Stocks tends to obscure these fine biennials, but it ought to have the opposite effect.

Sweet Williams

Sweet Williams were mentioned in the remarks on the genus Dianthus, and as there said, they are amongst the best of hardy biennials, admirably adapted for summer sowing, autumn planting, and late spring and summer blooming.

The Meadow Rues (Thalictrum)

The Meadow Rues (Thalictrum) are interesting and attractive on account of their Maidenhair-like foliage. Adiantifolium and Aquilegifolium are both very useful hardy border plants; in neither case are the flowers conspicuous.

The Spiderwort (Tradescantia Virginica)

The Spiderwort (Tradescantia Virginica) is worth growing. There are several varieties of it, which can be bought in mixture.

The Globe Flowers (Trollius)

The Globe Flowers (Trollius) can be raised from seed if desired, and are useful spring bloomers, with yellow or orange flowers.

Tunica Saxifraga

Tunica Saxifraga, a dwarf plant which bears masses of white flowers in early summer, has a good many admirers.

The Mulleins (Verbascum)

The Mulleins (Verbascum), notably Olympicum, are tall plants, with spikes of yellow flowers in early summer.