Saxifrage.—­These beautiful Alpine perennials delight in a light, sandy soil, and are easily propagated by seed or division.  It is most convenient to grow the rare and tender kinds in pots, as they require the protection of a frame in winter.  Saxifraga Sibthorpii is very suitable for the lower and damper parts of rock-work; it is hardy, and sheds its seed freely.  S. Umbrosa (London Pride) makes a neat border, and is also useful for rock-work.  S. Sarmentosa (Mother-of-Thousands) is a fine hanging plant for greenhouse or window.  They flower in April.  Height, mostly 4 in. to 6 in., but some grow as high as 1-1/2 ft.

Scabious.—­Ornamental and floriferous hardy biennials, which grow freely in common soil.  The seed may be sown at any time between March and midsummer; transplant in the autumn.  They bloom in June.  Height, 1 ft to 3 ft. (See also “Cephalaria.”)

Scale.—­Red Scale may be easily overcome with a strong solution of soft soap applied with a sponge.  White Scale is harder to deal with.  Syringe frequently with strong soapsuds heated to 120 degrees.  If the plant is badly attacked it is best to destroy it.

Schizanthus.—­Extremely beautiful and showy annuals.  A rather poor, light soil is most suitable for their growth.  For early flowering sow the seed in autumn, and keep the young plants in a frame or greenhouse throughout the winter.  For a succession of bloom sow in the open border early in the spring.  They flower in July and August.  Height, 2 ft.

Schizopetalum.—­This singular and delightfully fragrant annual does best in a mixture of loam, peat, and sand, or sandy loam and leaf-mould.  Sow the seed in pots in the spring, place in a greenhouse, and when large enough to handle, plant out in the open border, or it may be kept in an airy part of the house, where it will bloom in June.  Height, 1 ft.

Schizostylis Coccinea (Crimson Flag, or Kaffre Lily).—­A most lovely autumn-blooming plant, producing abundant spikes of Izia-like flowers about 2 ft. high.  It is suitable for pot-culture or planting outdoors, and is quite hardy.  It requires a rich, light soil.

Scillas (Squills).—­Very useful spring-flowering bulbs.  They are hardy, and do well in any position in light soil.  When mixed with Crocuses and Snowdrops they produce a very charming effect.  To get perfection of bloom they require deep planting.  S. Siberica especially looks well when grown in pots with Snowdrops.  Scilla roots are poisonous.  General height, 1 ft.

Scorzonera.—­Sow in March in light soil in rows 18 in. apart.  Thin the plants out to about 7 in. one from the other.  They may perhaps be ready for use in August, but to have large roots they should be left till they are two years old.  They may remain in the ground till wanted for use, or they may be lifted in October and stored like Beet, etc.  This vegetable is scraped and thrown into cold water for a few hours, then boiled in the same way as Carrots and Parsnips.