Rhododendrons are light feeders, so we recommend slow acting fertilizers which will not scorch the leaves when used as directed. Miracle-Gro Slow Release Fertilizer lasts the whole season and is very convenient. We developed our own slow release Rhododendron feed for best growth in the nursery and it's working really well for us. It's a great product which lasts 3 months and now our customers love it! Liquid feeds are excellent for quickly greening up any poor looking plants. Other products shown are useful to correct deficiencies in your soil.