Rhododendrons are usually trouble free in growing, provided care is taken in the initial planting.  Their main requirements are a lime free soil, plenty of water and some shelter from scorching sun and wind.  Autumn is the best time for planting as most roots are formed then.

Site Selection
A good rule of thumb is, the smaller the foliage, the more sun-tolerant.  Big leaved species, and hybrids such as the Loderis, are woodland plants and require shelter from wind and sun.  By sheltering the flowers from heat and sun, the longevity of blooming will be improved.  However, avoid planting too close to established trees and shrubs which can take all the moisture from the soil.  Also ensure that the soil is sufficiently well drained to prevent waterlogging in the winter.

We rarely receive complaints, but when we do, most problems are due to appalling site selection, compounded by a lack of water in the summer.

Soil Preparation and Planting
Rhododendrons are acid loving and prefer a well drained soil with a pH of 4.5 to 6, though they can be grown satisfactorily in neutral soils (up to pH 7).  Always dig a large hole, at least 2-3 times the size of the rootball, and incorporate leaf mould, peat, planting compost or well rotted manure into the soil.  Never use spent mushroom compost as this contains lime.  A light dressing of fertilizer is normally beneficial, but avoid this if the planting compost already contains fertilizer, or when planting any of the taliensia and neriiflora series of species, which are particularly sensitive to fertilizer.

Rhododendrons hate being planted too deep.  Plant the top of the rootball level with the soil and add 50-100 mm mulch of leaf mould, wood chips or bark to conserve moisture, insulate the soil, and reduce weed growth.

General Care
Newly planted Rhododendrons should receive a light fertilizer dressing in early March and after flowering.  They also require plenty of water, particularly during establishment in the first two seasons.  It should be remembered that many Rhododendrons originate from areas of high rainfall, such as the Himalayas, where rainfall can exceed 190 cm between May and September, compared to an annual British average of 75 cm.  A long soak once per week is better than a light daily sprinkle.  Rainwater is best, but tap water is better than no water.

For plants with a hardiness rating of less than H4, please give extra protection especially for the first 2 seasons.

Deadheading, Pinching and Pruning
After flowering it is well worth carefully snapping off all the faded trusses, just above the leaf collar.  This helps the plant to put its energy into new growth instead of unnecessary seed production.  Deadheading also gives the plant a well groomed look, and encourages blooms for the following season.

Pinching out single growth buds or single shoots at the tip of a branch in the Spring encourages two or more shoots lower down the branch to grow out.  In the early years this is particularly important as it helps to form a neat plant with dense foliage, which can support a greater number of blooms.