Whether collecting plum tree cuttings for rooting or grafting, a healthy cutting of young soft wood with a sufficient number of buds or leaf nodes is critical to successful propagation. Never allow your plum wood cuttings to dry out as this will likely render them useless. If storage is necessary before use, moist refrigeration can help extend the shelf life of the cuttings and keep them in good condition.
Harvest your plum tree cuttings in the late spring or in the late fall or early winter when the plum tree is dormant. Harvest your cuttings from the parent tree as close to the time of rooting or grafting as possible in order to use them at their peak viability.
Select several six- to eight-inch lengths of first- or second-year plum wood that is approximately the diameter of a pencil or crayon or a bit larger but not exceeding 3/4 inch in diameter. Ensure each length of wood cutting has several leaves attached or visible leaf axils if the leaves have dropped. Make a clean cut with your pruning shears and set the cutting into a wet paper towel while you finish collecting your remaining cuttings.
Keep the cuttings moist and store them carefully if not used immediately. Wrap in several layers of damp paper toweling and place inside a resealable clear plastic bag. Seal the bag up and place in the bottom half of the refrigerator for up to a few months' time. Check the cuttings periodically and remoisten the paper toweling when there is no apparent condensation in the bag or the toweling feels dry.