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.
From a commercial point of view the cultivation of herbs has sunk to a low ebb amongst market gardeners. Some thirty or forty years ago, however, many kinds were grown in large quantities between the rows of fruit trees and bushes, and in odd parts of the gardens where other crops could not very well be grown. The decline in the industry is largely due, no doubt, to the large supplies that are now imported from more favourable climes than our own, and at very much lower prices. And there are a few places in which medicinal herbs are grown for the purposes of the big wholesale chemists, but these are scarcely market gardeners in the usual sense of the term. Thirty years ago there were upwards of 1000 ac. within 30 miles of London devoted to the cultivation of herbs, chiefly in the neighbourhood of Mitcham, but now there are very few. There are, however, still some kinds to be met with in large or small patches in various places, private gardens having a greater variety than what is to be found in commercial establishments.