Rhododendrons require very little fertilizer if soil conditions are appropriate. Use a soil test to be sure the pH is acidic and, if needed, use a complete fertilizer such as 12-4-8 NPK.

Learn the best times and proper techniques for fertilizing azaleas for healthy growth and vibrant blooms. In the botanical world, all azaleas are rhododendrons (Rhododendron spp) but not all ...