This section is from the book "Commercial Gardening Vol4", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Mint (Mentha viridis), like Parsley, is a crop of which sales of great bulk cannot be made, and which does not suit the grower whose instincts run to large breadths of a few crops. It is nevertheless a useful crop to the man who is willing to take pains over the small things. Mint has the additional advantage that where a man has glass it forces well and provides a useful item in his house rotation.
Mint requires generous treatment and does best on light soil. Plants are obtained from lifting an old bed, and then pulling the young growths so that each has a little bit of root. These are planted with the dibber 1 ft. by 9 in. as early in the spring as the plants are big enough and the land available. The crop must be kept free of weeds and should produce a good cutting in July. Hoeing is difficult to carry out late, because the plants throw out runners, which, if undisturbed, will cover the ground and provide the young growths for the next year.
Where mint is grown for forcing it will not be cut but be allowed to die back naturally. The roots for forcing are forked out or turfed in November and laid in the houses, covered with a little light soil, and beaten down tight. Heat and plenty of water are required, and the crop can be gathered from the middle of January to March, when it may realize as much as 5s. per dozen bunches of about forty sprays each.
It is the practice with some to leave a piece of Mint down for several years, keeping it in heart by liberal topdressings of manure every winter. Unless great care is taken in dealing with weed growths the land will get very foul.
Some plough it up after the midsummer cutting of the second year, and put a crop of strong-growing winter greenstuff on the land; to keep up the supply a fresh piece is planted every spring. The price of Mint is 1s. to 1s. 6d per dozen bunches, each containing 3 to 4 dozen shoots, and a good piece will yield two or three cuttings during the summer. [w. g. l].