This section is from the book "The Gardener V2", 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.
Three species are generally grown, - Common Spearmint, Peppermint, and Pennyroyal. The first named is the variety generally grown in gardens for ordinary purposes. The leaves or tops are used in soups and salads, and every one knows that the indispensable Mint sauce is the accompaniment of roast-lamb. Mint is also a popular stomachic and anti-spasmodic, for which reason it is generally boiled along with green Peas and some other vegetables, according to taste or necessity. It is a native of Britain, and therefore hardy, thriving almost anywhere and in any soil, though it likes a damp situation, and grows best in wet seasons. It is propagated by division of the roots, and may be replanted every three or four years, in February or March. The ground should be dug deeply and manured, and the long runnerlike roots laid in, in rows about 1 foot apart, and covered 2 or 3 inches deep with soil. When the plants come into bloom, 8 or 10 inches of the tops should be cut off and dried for winter use. The beds should then be cleaned and top-dressed, and the plants will make a short growth before winter, which will afford a supply of green Mint also if needed.
Mint is easily forced; a few roots coiled round an 8-inch pot covered with soil, and pushed on in any forcing-house or pit, will keep up the supply. This sometimes requires to be done in spring. Peppermint and Pennyroyal require the same treatment. The first is grown for distillation chiefly, sometimes extensively by cottagers in England; the latter is occasionally inquired for in gardens.