Caring for rhododendrons and camellias

Evergreen foliage and incomparably beautiful flowers: these are the two great advantages of rhododendrons and camellias. To keep them looking their best, however, these shrubs need special treatment – from position and soil to water supply.

The right position

Rhododendrons and camellias do not like strong midday sun. An ideal spot is beneath deep-rooted, taller trees and shrubs; they also feel at home in the shade of buildings. They tolerate a few hours of sun well – provided the plants are shaded during the hottest hours of the day. Among rhododendrons, the compact varieties of Rhododendron yakushimanum, which stay small, are better suited to sunnier positions than the large-flowered hybrids, whose colours show to better effect in partial shade anyway.

Soil

All rhododendrons and camellias need acidic and, above all, loose, humus-rich soil. Light loamy soils enriched with leaf compost are ideal for camellias, as they guarantee the soil moisture these shallow-rooted plants depend on. For rhododendrons, the soil should always be improved with ericaceous compost or peat, as their even finer roots have to supply the plants with water and nutrients.

For these shrubs, which originally come from woodland regions, a ground-covering layer of leaf mulch is important: it provides an even supply of nutrients in the form of humus and protects the soil from drying out. Because their requirements are the same, other evergreen shrubs such as calico bush (Kalmia) and Japanese andromeda (Pieris) make good planting partners.

Feeding, pruning and watering

In February/March, the fertiliser is spread thinly over the root zone beneath the plants – after the layer of leaves put down as winter protection has been removed and the soil surface lightly loosened. Pruning is only done to emphasise the natural shape of growth; this encourages bud formation.

As the buds are set in summer once the shoots have finished growing, the plants must never suffer from drought during this time – otherwise camellias risk bud drop. Freshly planted specimens also need plenty of water in the first two years, at least during prolonged dry spells.

Good to know

• The faded flower clusters of rhododendrons only need to be removed for looks – setting seed is natural behaviour and does not weaken healthy plants.
• Camellia varieties of the Camellia x williamsii cross and some varieties of Camellia japonica are particularly hardy; “Hagoromo” and “San Dimas” are the front runners when it comes to winter hardiness.
• For lovers of scented flowers: Rhododendron auriculatum is hardy, grows into a very large shrub and only opens its large, pure white flowers in July – the fragrance is reminiscent of regal lilies.