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.
Thousands of Roses are grafted under glass each year between January and March, both on the Brier and Manetti stocks, for the trade in pot Roses. The stocks are lifted from the open and placed in a genial warm light soil a few weeks in advance of the budding season. The increased warmth excites the flow of the sap in the stocks, and once this is secured they may be budded at once. The kinds to be grafted must also have been started into growth in gentle heat to bring the sap into motion and thus secure the quicker union of the cambium layers in both stock and scion. Fig. 441 shows a piece of rooted Rose stock with the scion on the left, and on the right how they are placed together, at least one edge flush with the other, before being tied up with raffia. This is known as side grafting, and differs somewhat from the method of fruit - tree grafting in not having a tongue cut in either stock or scion. As a rule no grafting wax is used when Roses are being grafted under glass, but under certain conditions it is used to ensure success. In any case, when the scions have been properly attached and tied to the rooted stocks the latter are potted in rich gritty soil in small pots and are placed in a frame with a bottom heat of 65° to 70° F. They are kept close and moist for a few days, after which more air and light are gradually admitted. When firmly established the plants are taken out of the frame and placed in 5-in. pots, a good rich loamy compost being used. About the end of May they are transferred to the open air and plunged in ash beds, where they are watered and attended to during the summer until fit for sale from October onwards.
Fig. 439. - Inverted T-budding.
Fig. 440. - Budding Standard Brier Shoots.
Fig. 441. - Side Grafting Roses.
When weeping and climbing Roses are raised under glass they are often trained up beneath the rafters on a trellis, much in the same way as Vines, and in this way shoots from 15 to 20 ft. are developed in the course of one season. In late summer or autumn these long-shooted Roses are placed outside to ripen thoroughly, the shoots being trailed over the glass of the houses.