Spiræa (Spirea, Meadow-Sweet). Rosaceæ.
Seeds, sown as soon as ripe or stratified until spring. Commonly increased by cuttings, either of mature or green wood. Green cuttings usually make the best plants. These are made in summer and handled in frames. Some sorts, as S. ariæfolia, S. opulifolia and varieties (Nine-bark, now known as Neillia or Physocarpus opulifolia) and S. prunifolia, are usually grown from layers put down in spring. The herbaceous kinds are often increased by division.
Spondias (Hog Plum, Otaheite Apple or Plum). Anacardiaceæ.
Seeds; by large cuttings of growing wood, which should be inserted in sand or mould, in heat.
Spruce. See [Picea] and [Abies].
Squash (Cucurbita, three species). Cucurbitaceæ.
Seeds, when the weather becomes warm.
Squill. See [Scilla].
Stachys, Betonica, Galeopsis (Hedge Nettle, Woundwort). Labiatæ.
Seeds, divisions, or cuttings. Some species (as the Crosnes or S. tuberifera of recent introduction) are increased by subterranean tubers.