This section is from the book "The Gardener V3", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
Common or Red Sage is the variety generally grown. It is an aromatic herb, and is used for flavouring various articles of cookery.
In some countries it is used instead of tea, and also said to be smoked like tobacco. It was, and still is, a favourite of herb doctors. We can recommend it from experience, with honey and vinegar, as one of the best gargles for inflammatory sore-throat. Sage is a native of the south of Europe, and will succeed in any light well-drained soil, preferring a warm situation. It is generally propagated by cuttings of the young shoots, as soon as they can be got, about the beginning of summer. The cuttings should be inserted in a light sharp soil, under handlights, and shaded and watered till rooted. When hardened off a little, the plants should be lifted carefully, and planted out on the border, about 15 inches apart each way, and watered. The after-culture consists in stirring the soil about the plants, and keeping it free from weeds. A little light manure should be forked in about the plants in spring or autumn. The tops should be cut off before flowering, and dried for winter use. If this is delayed until it is too late for the plants to make a second short growth before frost sets in, they will frequently perish, or at least be greatly injured during the winter.
Sage may also be propagated, in an emergency, by seed, and by splitting the old plants into pieces, with a bit of root attached to each; but by cuttings is the best plan.