These details can be found on the Royal Horticultural Society’s website: http://www.rhs.org.uk/
As climate change presents us with the challenge of gardening with less water, choosing plants to suit our growing conditions becomes paramount.
Making our gardens more resistant to drought is not necessarily about digging them up and starting again, but thinking about appropriate soil cultivation, plant choice and garden maintenance.
Why do we need to think about drought?
All gardeners, especially those in the south of Britain, need to consider how climate change will affect the plants they grow.
Using different plants may mean that the feel of the garden will change, but dramatic plantings can easily be achieved from plants that have very low moisture and maintenance demands.
Many drought-resistant plants naturally form communities of plants which all thrive in the same conditions and come from similar Mediterranean habitats.
Make your garden more drought-resistant
The following tips will help make your garden more resistant to drought conditions:
Cultivate the soil deeply and dig in large quantities of organic matter to improve soil structure, soil water retention and water availability for plants. Well-rotted garden compost, mushroom compost, composted bark and well-rotted farmyard manure are all suitable forms of organic matter.
Apply sufficient fertiliser as plants use water most effiently where nutrient levels are adequate. But do not apply too much fertiliser to the soil, as this can encourage too much lush growth which can flop in summer, require extra watering, and become frost damaged in winter.
Choose plants with grey-green or silver leaves as they reflect the sun’s rays, helping to conserve moisture within the plant tissues.
Try to choose plants which suit the site’s soil type and aspect. They will be more tolerant of varying climatic conditions as well as of pest and disease problems.
Plant things while they are still small. They will develop much greater resilience as they adapt to their conditions from a young age. Ideally plant in autumn so they can do some growing before dry weather arrives.
If planting Mediterranean plants, do so in spring when the soil is warming up. Many of these plants will suffer from root-rot if planted in autumn and become cold and damp over winter.
Before planting, thoroughly soak the plants in their pots in a bucket of water until the bubbles stop rising to the surface.
Thoroughly water in all new plants (and keep them watered in the first season after planting to ensure they establish well). Once established, they will become much more drought-tolerant.
After planting, mulch the bed with 5-7.5cm (2-3in) of gravel or, even better, a layer of compost or straw covered with gravel, to help retain moisture while the plants establish.
Consider making a gravel garden. These are low maintenance and are a good option if you already have sandy or gravelly soil.
You may decide to do without a lawn in your drought-friendly garden, but if you cannot do without this feature in your garden, then you may be pleased to know that lawns are surprisingly drought tolerant, and usually recover well in the autumn rains, even if they have been brown and parched most of the summer. Lawn irrigation should rarely be required, if at all, to keep the grass healthy.
As climate change presents us with the challenge of gardening with less water, choosing plants to suit our growing conditions becomes paramount.
Introduction
With some conditioning of the soil and careful watering, there is a considerable range of plants that can tolerate dry conditions once they are established.
Practical considerations
• Plant any silver leaved, less hardy, sun lovers in April so they establish their roots well before winter arrives
• Try to plant small specimens so that they get used to their growing environment gradually as they develop
• Adding organic matter to the soil before planting can help to improve both water availability and drainage, but do not add fertiliser, as this can encourage too much lush growth which may flop in summer, require extra watering, and be affected by frost in the winter
• Use mulches to retain moisture in the soil
Suitable plants for drought resistant gardening
Many drought tolerant plants have silver or grey-green leaves, their light leaf colour reflecting the harsh rays of the sun. Some have a coating of fine hairs on their leaves or stems, helping to trap moisture around the plant tissues. Below is a selection of plants with good drought-tolerant properties.
Trees
Acacia dealbata (mimosa): Height 15-30m (50-100ft); spread 15m (50ft)
Cercis siliquastrum (Judas tree) : Height and spread 10m (30ft)
Koelreuteria paniculata (golden rain tree): Height and spread 10m (30ft)
Ptelea trifoliata ‘Aurea’ (hop tree): Height: 5m (15ft)
Conifers
Chamaecyparis lawsoniana (Lawson cypress): Height and spread variable according to cultivar
Cupressus arizonica var. glabra: 10-15m x 4-5m (30-50ft x 12-15ft)
Juniperus: Height and spread variable according to species and cultivar
Pinus: Height and spread variable according to species and cultivar.
Palms
Cordyline australis : 3-10m x 1-4m (10-30ft x 3-13ft)
Trachycarpus fortunei: (20m x 2.5m (70ft x 8ft)
Small shrubs
Artemisia ‘Powis Castle’: 60cm x 90cm (2ft x 3ft)
Halimium: Height and spread variable according to cultivar
Hebe: Height and spread variable according to cultivar
Lavandula (lavender): Height and spread variable according to cultivar
Nandina domestica (sacred bamboo): 2m x 1.5m (6ft x 5ft)
Ozothamnus ledifolius: 1m x 1m (3ft x 3ft)
Perovskia atriplicifolia ‘Blue Spire’ : 1.2m x 1m (4ft x 3ft)
Santolina chamaecyparissus: 50cm x 50cm (20in x 3ft)
Medium-large shrubs
Abelia × grandiflora : 3m x 4m (10ft x 12ft)
Arbutus unedo : 8m x 8m (25ft x 25ft)
Callistemon citrinus: Height and spread variable according to cultivar
Elaeagnus angustifolia: 6m x 6m (20ft x 20ft)
Olearia macrodonta: 6m x 5m (20ft x 15ft)
Ozothamnus rosmarinifolius ‘Silver Jubilee’ : 2-3m x 1.5m (6-10ft x 5ft)
Vitex agnus-castus: 2-8m x 2-8m (6-25ft x 6-25ft)
Climbers
Campsis: 10m (30ft)
Eccremocarpus scaber : 3-5m(10-15ft)
Jasminum officinale: 12m (40ft
Passiflora caerulea (e.g. ‘Constance Elliott’ ): 10m (30ft)
Solanum crispum: 6m (20ft)
Herbaceous perennials
Baptisia australis : 1.5m x 60cm(5ft x 2ft)
Euphorbia: Height and spread variable according to cultivar.
Eryngium: Height and spread variable according to cultivar.
Echinops: Height and spread variable according to cultivar.
Osteospermum jucundum: Height 10-50cm (4-20in) Spread 50-90cm (20in-3ft)
Verbena including V. rigida and V. bonariensis: Height and spread variable according to cultivar
Grasses
Cortaderia selloana: 2.5 -3m x 1.5m (8-10ft x 5ft)
Panicum virgatum: 1m x 75cm(3ft x 30in)
Pennisetum alopecuroides: 0.6-1.5 x 0.6-1.2m (2-5ft x 2-4ft)
Stipa gigantea: 2.5m x 1.2m(8ft x 4ft)
Briza media
Pennisetum rubrum
Containers and borders
Alonsoa
Amaranthus
Arctotis
Argyranthemum
Bidens
Brachyscome
Calendula officinalis (pot marigold)
Cerinthe major
Convolvulus sabatius
Cosmos bipinnatus
Diascia
Eschscholzia californica (Californian poppy)
Felicia
Gazania
Gomphrena globosa
Helianthus (sunflower)
Helichrysum petiolare
Heliotropium
Helipterum roseum (syn. Rhodanthe chlorocephala subsp. rosea)
Ipomoea purpurea
Lantana camara
Lavandula multifida, L. dentata
Limnanthes douglasii
Limonium sinuatum
Mesembryanthemum
Mirabilis jalapa
Nemesia
Nicotiana
Nigella damascena
Osteospermum
Papaver somniferum
Pelargonium
Plectranthus
Portulaca grandiflora
Senecio maritima
Silybum marianum
Tithonia rotundifolia
Tropaeolum majus
Verbena
Zaluzianskya ovata (night phlox)
Half-hardy succulents
Aeonium
Aloe
Aloe arborescens ‘Variegata’ Delosperma cooperi
Drosanthemum
Lampranthus
Hanging basket plants
Bidens
Brachyscome
Convolvulus sabatius
Diascia
Felicia
Nemesia
Pelargonium – trailing and zonal
Tropaeolum majus
Verbena
Further details can be found on the Royal Horticultural Society’s website: http://www.rhs.org.uk/
