Rhododendron

There are over one thousand varieties of rhododendron. These shrubs are grown commonly in the UK for their large, colourful flowers and sometimes also for their autumn colour. Rhododendrons do better in areas of high rainfall and prefer an acid soil, so will not be very successful in drier regions will chalky, alkaline soil. Rhododendrons are great for adding a riot of bold colour and drama to your garden.

Growing rhododendron

Rhododendrons require an acid soil with a pH of 5.0 or 6.0. They are surface rooting and should not be planted too deeply. Roots should just be covered. The best sites for rhododendron are ones with dappled shade in sheltered conditions though a more open aspect should be fine if they are sheltered partially at least from any cold, dry winds. Dwarf alpine species will tolerate full sun as long as the soil does not dry out.

Rhododendron plants should be planted in areas prepared with plenty of acidic organic material incorporated into the soil. You could use composted tree bark, leafmould, decomposing pine needles or composted chopped bracken, though note that if you live in an area with alkaline soil you would be best to grow rhododendrons in pots as reducing soil pH is not very easy.

Never let rhododendrons experience drought as they will definitely suffer if they do not get enough water. Always try to use rain water rather than tap water to water rhododendrons, but if necessary tap water can be used for a couple of months over the summer if rain water runs out.

It is not necessary to prune rhododendrons unless you wish to so so to shape train or keep in bounds. You can remove dead wood and deadhead flowers if it is practical to do so. Many rhododendrons, if they have become straggly and over-large, respond well to a hard cutting back after which they can be easily kept in shape with light pruning every now and then.

You can propagate rhododendrons by taking cuttings, grafting or layering, or you can grow them from seed, though most people will not bother with this option. Cuttings are semi-ripe wood pulled away with a portion of the stem and should be wounded to encourage rooting. Alternatively, there are usually a choice of rhododendron in many garden centres.

Why grow rhododendron in the garden?

Larger rhododendrons are perfect for woodland gardens while dwarf varieties are great in rock gardens and the smallest examples do well in pots. This means that a rhododendron could be an exciting and interesting addition to almost any garden.

As ericaceous, acid-living plants, rhododendrons have good companions for other plants with the same requirements. Many are evergreen meaning they can brighten up the garden and give it structure all year round.

Rhododendron has long been used in traditional medicine though it should also be noted that it is poisonous to pets and livestock, especially horses, so care should be taken. 

Quick Facts

Latin Name
Rhododendron (various)