Wait until the new growth is somewhat mature; here in central Virginia that's about mid-june. I have had some degree of success using Hormodin #3 instead of Rootone and after coating the cuttings with the hormone, trim the leaf area to ca. i/3. then place them upon a bed of fine Vermiculite contained in aclear plastic shoe box. Cover cuttings with at least 1 inch of additional Vermiculite, water, seal, and place in a coolish place. In ca. 6 weks roots should have formed. These wild Rhododendrons are quite
difficult to root, so don't hold your breath!