Steve Huddleston is Senior Horticulturist at Fort Worth Botanic Garden,
www.fwbg.org
Tony Sharley is an Environmental Scientist and Manager of Banrock Station, South Australia, www.banrockstation.com.au
Nigel Dunnett is a Reader in Urban Horticulture and Director of The Green Roof Centre & Graduate Research Co-ordinator at the Department of Landscape, University of Sheffield.


What are your top tips for water-wise gardening?
Steve says: Improve the soil by working in three to four inches of well-rotted compost. This will add nutrients, increase moisture retention and loosen heavy soils. Select water-wise plants such as those that are native and/or adapted to your climate. Add two to three inches of mulch to the surface after planting; this stabilises soil temperature, inhibits weed growth and conserves moisture in the bed.

Tony says: Look at your location. Is it wet or dry? Is your soil sandy (good drainage) or clay (poor drainage)? Check the depth and texture of your soil by digging a small hole and see how far down plant roots penetrate. Base your plant selection on these factors. Next, mulch the ground and water areas for longer but less frequently. Water soaks deep into the root zone and encourages deep root zone development, so plants cope better if water is limited by restrictions and drought.

Nigel says: I don't have any bare soil in my garden - it is all covered in plants. And those plants need no watering. I always look to nature – what plants and plant groups survive and thrive in the driest of places – and I base my planting selection on what I find there.


Does my garden have to look like a desert?
Steve says: Not at all. Many native and adapted plants are colourful in flower and their foliage is often dramatic and architectural, offering different shapes. The most architectural plants are species of Agave, the giant hesperaloe (Hesperaloe funifera), red yucca (Hesperaloe parviflora), and the beaked yuccas (Yucca rostrata). Other native plants with spectacular colour throughout the year include autumn sage (Salvia greggii), ox-eye daisy, desert willow (Chilopsis linearis), Texas sage (Leucophyllum frutescens), chaste tree (Vitex agnus-castus), and Texas lantana (Lantana horrida).

Tony says: No, your garden can be as beautiful as you want it to be. Use plants and grasses native to your region to create an oasis reflective of the natural beauty of your area. Then your garden will be better suited to withstand changes in the climate with minimal intervention. In freely drained soils or containers, species such as yucca, lavender, thyme and sage are good choices.

Nigel says: We are not in a desert climate because our winters will always be relatively cool and wet. Think instead of beautiful wildflower meadows that thrive in the wild on thin dry soils. And then be inspired to work with dramatic naturalistic mixes of grasses, perennials and bulbs from dry places, that will give sparkling colour and soft textures, rather than the alien spikes and points of the desert.


Will my lawn have to go?
Steve says: No, but I would encourage you to reduce the amount of lawn in your garden because turf uses more water than other landscape plants. If you are set on having a lawn try to source a native turf (such as buffalo grass in Texas) that looks good and requires less water.

Tony says: The good news is your lawn can stay, just make sure you select a low-maintenance and low-water-using species, such as RTF (Rhizomatous Tall Fescue) turf. This grass is great for areas of drought or partial shade and is readily available in Britain. It has roots that go deep into the soil, so withstands periods of drought, as well as water-logging.

Nigel says: I don't favour replacing lawns completely with hard surfaces, since lawns always recover surprisingly quickly in the autumn and winter. Lawns do allow water to infiltrate back into the soil after heavy rainstorms, and are food source for garden birds. We need to rethink the notion of a green summer lawn, and accept the concept of a seasonally changing, flowering garden lawn that is cut a bit less frequently.

Our essential guide to water-wise versus no-water gardening

What is the difference?
Water-wise gardening relies on careful watering of plants, directing and controlling the applications of water, so that none of it is wasted.
In a no-water system, only precipitated rain water is used to irrigate plants.
Soil treatment
In both systems, improvement to the soil structure is recommended. Soil needs to have nutrients from well-rotted manure, which also improves structure for drainage. Grit should be added to heavy clay soils to improve drainage, while sandy soils need organic matter to improve structure. Once plants are in place and watered in well, a physical mulch or bark or grave, or other suitable material, is applied over the soil surface. This reduces evaporation, keeps the soil moist and reduces the need to water. It also suppresses weeds that compete for water.
Plants
In a water-wise garden, you can grow your plants of choice but assess their watering needs and be sure you can provide for this by conserving rainwater or using trickle irrigation (see below).
In a no-water garden, choose plants that have grey or silver leaves as they deflect sunlight. Plants with fine hairs or a waxy coating to the leaves will hold moisture from the air and some plants, such as succulents, have specially adapted leaves that store moisture. Choose plants with small foliage that have low, mounding growth habits. Choose plants that originate from areas where the climates are dry.
Solutions
In a no-water system, the plants and the amendments to the soil mentioned above should keep the garden going well and you will not need to water.
Water-wise system
Conserve water run-off from roofs of the house and outbuildings in water butts attached to the downpipes. Install drip-irrigation systems instead of sprinklers and overhead watering systems. Use water cans or hoses but direct the water into the ground at the base of the plant rather than all over it.
General advice
Water early in the morning or late in the evening, when it is cooler and the plants are not actively transpiring and losing water. Avoid watering in windy conditions or in the heat of the day as this will damage plants and increase evaporation.
Plant into deep containers, so you don't have to water so frequently, and group containers together. Use special multi-plant watering systems and add moisture-retentive gel or granules into the compost when planting up pots.

Water Supply regulations
Current legislation only allows water companies to ban the use of hoses or sprinklers to water gardens or wash cars. However on 22 October 2007, Environment Minister Phil Woolas announced changes that will allow water companies greater discretion over restricting different types of uses of hosepipes. For example, during the next drought, water companies could ban the use of pressure washers, filling pools and hot tubs.
Water supply regulations are set to change during 2008. The changes are likely to eradicate loopholes and there are likely to be exemptions for certain types of water-saving irrigation systems, such as drip-watering systems, and possible hosepipe bans on alternate dates or at certain times of the day only.
(www.defra.gov.uk/Environment/water/resources/drought/index.htm)

Watering Equipment and its usage
Watering cans are good for small areas and individual plants and containers.
Use a hosepipe, with a variety of nozzle shapes and direct the water at the ground around the plant.
Seep or drip-hoses are laid onto the ground around plants. They are porous and the water seeps out into the soil. In drip irrigation systems the water drips out of holes in tubing. These systems can be adjusted to supply water at different rates and at times that you can regulate with a timer system. You also need to fit a one-way valve onto the outdoor tap to stop water being siphoned back into your drinking water system.

Waterwise gardens in Britain
The Beth Chatto Gardens, www.bethchatto.co.uk
Hyde Hall, www.rhs.org.uk/WhatsOn/Gardens/hydehall/
The Eden Project, www.edenproject.com
Sticky Wicket, www.stickywicketgarden.co.uk
The Old Vicarage, East Ruston, Norfolk, www.e-ruston-oldvicaragegardens.co.uk

The Banrock Station garden at the Eden Project in Cornwall demonstrates that a positive impact can be made by making a few smart decisions, such as using water-saving techniques and Forest Stewardship Council-certified and recycled timber, and planting a wide range of plants to attract wildlife and using locally supplied hard landscape materials.


Specialist books
Rain Gardens by Nigel Dunnett and Andy Clayden, Timber Press, £25.
The Dry Garden by Beth Chatto, Orion, £8.99.
RHS New Gardening by Matthew Wilson, Mitchell Beazley, £18.99.

Advice and information
Royal Horticultural Society, www.rhs.org.uk/advice/watering.asp
Office of Water Services (OFWAT), www.ofwat.gov.uk
Water UK, www.water.org.uk


Watering products and equipment
Harrod Horticultural, www.harrodhorticultural.com
The Garden Equipment Catalogue, www.ferndale-lodge.co.uk
The Water Group, www.watergrouppromotions.co.uk

Useful American websites include:
www.publicgardens.org
www.npsot.org
www.wildflower.org

Further information from Australian web resources includes:
ww.helpushelptheearth.com.au

WORDS BARBARA SEGALL