The Auctarian of the Botanic Garden, part 1. p. 40 (no. 75) (1849?)
Benjamin Maund

75 Laying Chinese Roses. "About the beginning of July, just when the tree is coming into flower, being provided with a sharp knife, and a few hooked pegs, commence by taking hold of the shoot intended to be layered, and making an incision just below the bud, on the upperside of the branch, pass the knife half way up to the next bud; then give the branch a slight twist, that the part so cut may rest upon the soil; fix in the peg, to hold the layer in its place, and cover it with soil, to about the depth of two inches. The custom of layering without the incision, so greatly retards the striking of the roots, that frequently they cannot be detached from the stools till the following spring; whereas if the incision be made, they will be ready, in favourable seasons, in two or three months."