By RSBG Nursery Manager & Assistant Curator, Atsuko Gibson Rhododendron Potting Media The Rhododendron Species Botanical Garden is always on the lookout for the best potting media for species rhododendrons. After conducting numerous experiments with various soil types and ratios, we’ve settled on our current mix: 30% small lava rock and 70% fine bark. Visitors … Continue reading RSBG’s Secret: Crafting the Ultimate Potting Media