Rhododendrons for Hedging and Screening
Recent research has proved that rhododendrons make one of the best sound barriers. Their dense, pendulous, evergreen leaves reflect noise pollution away. Few other species are as effective, and none can offer such stunning trusses of flowers.
What size and shape do you want?
Fast vigorous Hardy Hybrid rhododendrons are normally specified for tall hedges and screens growing to heights of 2 metres in 10 years. However, Yakushimanum varieties are used extensively in German front gardens to make feature hedges around 1.2 metres tall in 10 years. It is usual to let rhododendrons develop naturally into dome shaped bushes, but trimmed hedges with a square profile are also possible and take up less space. Where this is required, light pruning should take place immediately after flowering, to allow flower buds to develop in time for the following season. Smaller growing varieties can also be planted in front to give more colour and depth to the border.
What is your flowering scheme?
The best colours are red, pink, white and mauve shades. Yellows and oranges are also possible, but are slower growing, require better conditions, and can be thinner and less effective at screening. Hedges can look stunning when just one single variety is chosen. Also effective is a single row of 2 varieties planted alternatively and chosen to flower at different times. However, most informal screens and boundary plantings consist of several or many different varieties. In this way, a flowering season from February through to June is quite possible. Where space permits, planting in groups of 3 is recommended, as this adds more impact to the flowering, particularly when seen from a distance.
What conditions are required?
All rhododendrons require an acid soil (pH between 4.5 and 6.0) unless Inkarho rootstocks are specified which are suitable for neutral soils (pH 6.0 - 7.5). Soils must be kept moist in summer, and not waterlogged in winter. The varieties listed here are all tough and well suited for hedging. They will all take full sun or shade. In full sun, the flowers will tend to bloom more readily, but not last so long, and the plants may be a little shorter. In deep shade, early flowering varieties may be protected from late frosts, late varieties will last longer without the sun to burn them, but growth (and hence flowering) can be more sparse. Semi-shade is ideal.
Key Points
Allow room for the plants to grow. A plant which is 2 metre high after 10 years will require 2 metre spacing. (See the plant description for heights at 10 years and use this height as a spacing guide.) Do not plant too close to walls, fences, drives etc. Avoid planting too close to existing strong hedges, trees, and dry banks.
Before planting, thin any trees and remove any low branches.
Do try to plant in the autumn, when the ground is warm and establishment is easier. Planting is also fine up until the end of March.
Rhododendrons hate being planted too deep, and it is the most common cause of failure. Do not plant any deeper than the top of the pot or rootball.
Plant them well, and they will reward you well. Use plenty of organic leaf mould, or well rotted compost, with a light feed of fertiliser (e.g. Vitax Conifer & Shrub). Avoid animal manures, mushroom compost and bonemeal which are all unsuitable for rhododendrons.
Mulch with bark or leaf mould, and ensure the roots are kept free of weeds and grass.
Dead head old flower heads for the first few years.
Recommended Varieties
We can recommend the following varieties which are all dense to the ground and give plenty of privacy. We normally keep in good stocks, but please remember that we do sell out, and we recommend early ordering. We do not recommend R. ponticum which can prove particularly invasive, and seems prone to the new disease Ramorum Dieback. R. Fastuosum Flore Pleno is more appropriate.
Tall (1.8 metres after 10 years)
| Albert Schweitzer |
Pink |
Late May |
| Beau Brummel |
Red |
June |
| Betty Wormald |
Pink |
Late May |
| Fastuosum Flore Pleno |
Lavender |
Late May |
| Furnival's Daughter |
Pink |
May-June |
| Gomer Waterer |
Pinkywhite |
Early June |
| Jean Marie de Montague |
Red |
Early-mid May |
| Lem's Monarch |
Pink |
Late May |
| Lord Roberts |
Red |
Early June |
| Madame Masson |
White |
May-June |
| Mrs Charles Pearson |
Pinkywhite |
May-June |
| Mrs T H Lowinsky |
Pinkywhite |
June |
| Pink Pearl |
Pink |
May |
| Scintillation |
Pink |
Mid May |
Medium (1.5 metres after 10 years)
| Caucasicum Pictum |
Pink |
April |
| Christmas Cheer |
Pink |
March |
| Cosmopolitan |
Pink |
Early May |
| Cunningham's White |
White |
May |
| Red Delicious |
Red |
Late May-June |
| Taurus |
Red |
April-May |
Yakushimanum (1.2 metres after 10 years)
| Dopey |
Red |
Late May-Early June |
| Dreamland |
Pinkywhite |
May |
| Fantastica |
Pink |
May |
| Hoppy |
Pale lavender |
May-June |
| Hydon Dawn |
Pink |
May |
| Marlis |
Pink |
May |
| Percy Wiseman |
Creamy pink |
May |
| Surrey Heath |
Pink |
May |