Dry Gardens

The term “dry garden” is applied to a garden that will work in an area of low rainfall without any artificial irrigation. Planting uses drought tolerant plants and surfaces are mulched, usually with gravel, to retain moisture.

The theme of dry gardens has developed since Beth Chatto created her dry garden on the old car park at Elmstead Market.

Beth Chatto Gardens

Various other gardens have followed her lead and the concept has now gained some popular appeal. The best known gardens in East Anglia are RHS Hyde Hall (Rettendon, Essex)

RHS Hyde Hall

and East Ruston Old Vicarage (Norfolk).

East Ruston Old Vicarage

However, this is not simply a fashion trend. Dry gardens meet a specific environmental and horticultural need

Why a dry garden?

East Anglia has the lowest average rainfall in the UK (in the range 500-600mm). Recent summers have been even drier and climate change may make summers drier in the future. To put the rainfall level in perspective, this area is drier than the Eastern Mediterranean.

There are two alternative approaches to this problem. Traditional English gardens can be maintained, using water to keep plants healthy in dry spells. This becomes more difficult as the pressure on limited water resources has led to hosepipe bans; metering of water means gardeners have to pay for the water they use. Rainwater storage is usually too limited and most people do not wish to modify their homes to re-use ‘grey water’ (waste from baths and washing machines).

The second approach is to use plants and gardens that require minimal water and will survive or (better) thrive in the prevailing conditions. In this way the garden works with the natural environment rather than against it and constant intervention to deal with the problems of an essentially artificial construct is avoided.

Choice of plants

Plants that are adapted to dry conditions show one or more of the following adaptations.

Tough leathery leaves
Grey / Silver leaves – reflect light.
Hairy leaves (often giving grey or silver colour) reduce moisture loss
Succulent plants, lower surface : volume ratio reduces water loss. Fleshy structure holds water.
Deep roots to access water in the subsoil

Many plants from the Mediterranean and from desert areas are suitable, the only restriction being that UK conditions in winter are cold and damp. Not all desert adapted plants are fully frost hardy. Many will survive cold provided they are relatively dry. Any water-logging is fatal. However, many areas have naturally free draining sandy soil and clay soils can be improved (as in the RHS garden at Hyde Hall) by raising the planting area, adding drainage layers below the soil and working large volumes of grit into the soil.