Preserving water is proving to be of increasing importance, nowhere more so than within a garden. By making some careful selections, and using simple techniques, dramatic plantings can be achieved that require low maintenance and have minimal moisture demands.
Climate change
With drier summers it can be well worth taking action to help plants survive through particularly dry periods. Development can be severely restricted by a lack of available water. Drought during summer, when temperatures and sunlight are at their highest levels, is a common problem. A plant’s functions slow down until more water is available, although water loss by transpiration is reduced by partial closure of stomata in the leaves.
Read more about our changing climate
Suitable plants
When planning a new garden or border consider using more drought-tolerant plants. Vegetation originating from regions of low rainfall often has special adaptations such as spiny, narrow, glossy, hairy, sticky or fleshy leaves that help reduce water loss through transpiration.
The Dry Garden at RHS Garden Hyde Hall (left and right) demonstrates planting of this type. However, even drought-tolerant plants may need watering until they establish.
Organic matter is the key to improving soil performance, in both drought and flood. Adding organic matter as a surface mulch reduces evaporation from the soil, while digging in organic matter improves water-holding capacity, especially on thin, sandy or chalky soils. Organic matter helps bind clay soils into crumbs, so water infiltrates more quickly after a downpour, and makes water more easily available to plant roots, which can grow through gaps between the crumbs.
Drought-tolerant plants include:
Trees and palms Acacia, Cercis, Robinia, Chamaerops, Cordyline, Crataegus and many conifers
Shrubs and hedges Cistus, Lavandula, Hebe, Ceanothus, Elaeagnus, Photinia, Phlomis and Ilex
Climbers and wall-shrubs Hydrangea anomala ssp. petiolaris, Jasminum, Parthenocissus, Solanum, Wisteria and Pyracantha
Herbaceous Achillea, Geranium, Nepeta, Sedum, Dianthus, Crambe and Echinops among many others
Grasses many genera including Stipa, Pennisetum, Cortaderia and Panicum
Ground cover Stachys, Vinca, Liriope muscari, Juniperus horizontalis, Thymus, Alchemilla and Santolina
Bulbs (many prefer dry conditions) Crocus, Scilla, Tulipa, Allium and Colchicum
Annuals Alyssum, Brachyscome, Lunaria, Salvia, Cosmos and Eschscholzia
Retaining moisture
Gravel gardens lend themselves to drought-tolerant planting in unpredictable climates, but are certainly not the only option (read Matthew Wilson's article Adaptation: the key to survival). It should still be possible to keep to an established style of garden but to use different species and/or change growing techniques, at least in the short term. Succulents, cacti and architectural plants such as palms work well in mild gardens.
Turf care
'Lawns are high maintenance features and require considerable time and effort to look their best. There are a number of steps, however, that can be taken to help turf withstand drought.
Weeds compete with grass for resources so should be removed. Lawns can die back quickly during summer resulting in straw-coloured patches, regrowth of which can be slow. Raising the cutting height of the lawnmower can reduce drought stress slightly. To increase drought tolerance, scarify the lawn in autumn to remove thatch build-up. Although a thin thatch layer can act as a mulch (and make the turf more resilient), a layer greater than 1cm (3⁄8in) can impede water penetration. Use a spring-tined rake or hire a motorised scarifier. Regular aeration is important for moisture penetration to the root zone.
Drought & watering
Water storage
Water conservation
Economical watering
Watering techniques
When to water
Hosepipe bans and restrictions
Sarah Durrant