Nuganics

At this time of year many of us think about rhododendrons. Although the different types flower for a long period, it is in May that they really make an impact on gardens across the land. But 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 favourite container, consider a few basics. Choose a dwarf rhododendron — many can get huge but there are lots of compact varieties, such as the ‘Bow Bells’ I chose, or all the Yakushimanum varieties (’Yaks’). Then think about the pot. It should not be made of concrete or contain lime and must have straight sides so that, when the time comes, you can get the roots out of the pot to move it into the next size. It must also have drainage holes but if it has a saucer which can be topped up with water in summer, that is of benefit. You must use a lime-free compost. There are many brands of lime-free, or ericaceous compost but most are loam-free. Most are not, in my opinion, good for long-lasting plants and I prefer to use lime-free John Innes compost, possibly mixed with some fine bark.