Purchase plants of varieties suitable for indoor culture, including miniatures, or dig some from your garden in the fall. Pot in a mix of 3 parts garden loam and 1 part peatmoss or well-rotted manure, in pots large enough to take entire root system without squeezing and to allow for additional growth. Place on sides in cold-frame or protected area and cover with sufficient hay or straw to prevent freezing.
In late December, bring into the greenhouse, place under the bench and syringe frequently to promote bud development; move up to the bench. Mulch with peatmoss to prevent drying out roots, but avoid overwatering. Fertilize periodically while in active growth. If you plan to grow them in the greenhouse for another year, plunge pots outdoors during summer.
In early October, inspect carefully for insects and repot if necessary; otherwise, remove an inch of topsoil and replace with fresh soil. Place in coldframe and repeat cultural directions above. If pruning is necessary, do it just before placing in coldframe, or before the roses are brought into greenhouse for forcing.
A 60 to 70 per cent humidity in the greenhouse and controlled ventilation are beneficial. Spring cuttings root in about 2 months with bottom heat of 70 F. Pot in 2/2-inch pots and shift to larger pots as necessary. Dust roses with sulfur to eliminate mildew. Red spider and aphids may attack roses.