Scutellaria.—­These plants will grow in any good soil.  The hardy perennials flower in July.  The greenhouse varieties merely require protecting in the winter.  They all bear division of the root, and are easily raised from seed.  Height, 1-1/2 ft.

Scyphanthus.—­An elegant and curious trailer, which is best grown in a loamy soil.  It may be increased from seed sown in April, and it flowers in August.  Height, 2 ft.

Sea Cabbage.—­See “Crambe Cordifolia.”

Seakale.—­The readiest way of propagating this useful vegetable is by off-sets, but it may be raised from seed sown in March or April in rows 1 ft. apart.  Thin out the young plants to 6 in. in the rows, and transplant in February or March into well-trenched, deep, rich soil in rows 2 ft. apart and the plants 15 in. asunder.  Keep the plants to one crown, or shoot, and remove all flower-shoots as they appear.  In dry weather give a liberal quantity of liquid manure.  Cropping may commence after the roots have been planted two years.

Sea Lavender.—­See “Statice.”

Sea Milkweed.—­See “Glaux.”

Sedum (Stonecrop).—­This well-known hardy perennial is suitable for pots or rock-work.  It delights in a light, sandy soil, and is readily increased by division or cuttings.  It flowers in June or July.  Height, 3 in.

Seed-Sowing.—­Two of the most important points in the sowing of seed are the proper condition of the ground and the regular and uniform depth at which the seed is sown.  Seeds require light, heat, air, and moisture for their germination.  The ground should be light, and in such a condition that the young roots can easily penetrate it, and in all cases should be freshly dug so as to communicate air and moisture:  it should be neither too wet nor too dry.  The most favourable time for seed-sowing is just before a gentle rain.  If sown too early on cold, wet ground, the seed is apt to rot; when sown too shallow in a dry time, there may not be sufficient moisture to cause it to sprout.  The seed should be sown evenly.  The size of a seed is a nearly safe guide as to the depth at which it should be sown.  For instance, Beans and Peas of all kinds should be sown about a couple of inches deep, while very small flower-seeds merely require to be just covered.  As to the time for sowing, see “Annuals,” “Biennials,” and “Perennials.”

Seeds, the Protection of.—­In order to protect seeds against birds, insects, and rodents, soak them in water containing 20 or 25 per cent, of mineral oil.  Vegetable seeds, such as Haricot Beans and Peas, should be soaked for twelve hours, and the pips of Apples and Pears for double that time.  For soaking the finer seeds, bitter liquids, such as that of Quassia and Gentian, should be used.

Sempervivum (Houseleek).—­The hardy kinds are well known, and may often be seen growing on the roofs of cottages and on walls.  They make good rock-work plants, and are easily increased by off-sets.  The more tender kinds are suitable for the greenhouse.  These should be planted in sandy loam and old brick rubbish.  They require but very little water; more may be given when they are in flower.  Cuttings, after being laid aside for a day or two to dry, will soon make root.  Height, 6 in.