BLANCHING, among gardeners, an operation whereby certain fallets, roots, &c. are rendered whiter than they would otherwise be.—It is thus: After pruning off the tops and roots of the plants to be blanched, they plant them in trenches about ten inches wide, and as many deep, more or less, as is judged necessary; as they grow up, care is taken to cover them with earth, within four or five inches of their tops: this is repeated from time to time, for five or six weeks; in which time they will be fit for use, and of a whitish colour where covered by the earth.
BLANCHING also denotes the operation of covering iron plates with a thin coat or crust of tin.