Q: Can you simplify rose pruning for me? Most books make it seem difficult, and most of my friends don't know too much about it, either. --R.S., Baldwin Park A: Staff at the Los Angeles State and County Arboretum as well as at Descanso Gardens and South Coast Botanic Garden tell me that how to go about pruning roses is one of the questions most frequently asked. They advise pruning in February when roses are at their most dormant stage. They begin by pruning away dead twigs and then all weak or spindly stems. Those stems smaller than a pencil in diameter should be removed with cuts made just above healthy, outward-facing buds. This results in a vase-shaped bush, open in the center so air can circulate. All other canes should be cut back by one-third. Any cuts larger than a pencil in diameter should be sealed with a pruning compound to prevent damage by disease and other pests. In the case of climbing roses, most long canes should be retained and secondary branches left with two or three buds on each. Descanso Gardens holds an annual pruning demonstration each year, as does Rose Hills and the Exposition Park Rose Garden.