How to Plant and care for Rhododendrons
Rhododendrons must have lime-free soil and that can make them tricky for some of us that garden on neutral or limey soils. Planting in the garden is a waste of time and money. If you want, you can make a raised bed and fill that with acid soil but digging a hole in your garden and filling it with acid (ericaceous) compost only works for a while. The water from the surrounding soil will drain in and spread the lime and although you can acidify soil with sulphur chips you really are making life hard for yourself.
By far the best way to grow rhododendrons in these circumstances is to put them in pot. Rhododendrons have compact, fibrous roots and grow well in containers. But before you rush out and plant one in your favorite container, consider a few basics tips from this gardening tutorial.