After another spring of droughts and heavy downpours, there is no avoiding the fact that we need to think differently about water. While we escaped a ban in 2011, a hosepipe ban is already in place for 2012, which means unlimited water on tap is no longer something we can take for granted. And as climate change escalates, neither is moderate, adequate rainfall. Meanwhile, our demand for water is increasing exponentially; Britain uses 70 per cent more water than it did 40 years ago. This necessitates the building of more treatment plants and the processing and transportation of more and more water, all of which expends energy and resources and contributes to climate change. The fact that we cannot garden without water does not mean that we have the right to go on gardening as we have always done, regardless of the demands our plants are making on the planet’s resources. A sprinkler or hosepipe uses 540 litres (119 gallons) of water in an hour – only slightly less than an average family of four uses in a day. As a result, hosepipe bans look set to become an annual occurrence.
The good news is that it is entirely possible to have a lush, thriving garden that is independent of mains water. There is a whole range of ways of achieving this, suitable for all styles and sizes of gardens and all types of gardener. Using less water in the garden will significantly reduce your overall water consumption, and collectively, gardeners can make a huge contribution to reducing the demand for mains water. In built-up areas, much of the ground is covered by hard surfacing that prevents rainfall from draining naturally. Besides the ecological reasons for using less water in the garden, there is a financial incentive; as water meters become the norm, using less water will translate into lower water bills. And there is a practical one; watering by hand is one of the more laborious - and least enjoyable - aspects of gardening. If we design and manage our gardens in waterwise ways, we will have more time to enjoy them.
Achieving a waterwise garden is a three-part process, and the first step is to design your garden in a water-efficient way. This is not only relevant to new gardens; all gardens are remade over time, and as your garden evolves you can factor water-saving into the process. As with most things, it helps to have a plan. Start by assessing your garden as it is today. Think about where different plants and features are located, what their water requirements are, how water is currently harvested or recycled (if at all), and how and where it is used. Note any water-related problems in your garden, and work out why they are occurring. Then think about your garden’s potential for development: which features could be moved, or changed, to reduce their water needs, or make watering easier? How could you harvest or recycle more water? What could be done to remedy problems like poor drainage? Armed with a list of existing problems and potential solutions, you will be in a position to move forwards.
Water requirements are affected by shade and shelter, so you need to think about your garden as a whole. You can reduce your garden’s water needs by, for instance, adding a screen to filter the prevailing wind, or a trellis to create dappled shade. A sloping garden will have particular problems with water run-off. ‘Grading’ and ‘soil contouring’ can help to direct water to planted areas. Think about the plants you are growing; could you be making more waterwise choices? A basic premise of ecological gardening is to grow plants suited to the conditions you can provide, rather than trying to alter existing conditions to accommodate unsuitable plants. This may mean growing more perennial plants and fewer annuals – perennials, as a rule, put down deeper roots. It may mean growing more drought-resistant plants – ones with grey, thick, hairy, small or aromatic leaves generally need less water than those with large or soft leaves. Given how vast the range of cultivated plants is, your garden will be none the poorer. It may mean thinking more carefully about where to put plants, or growing fewer plants in containers; hanging baskets in particular are not a waterwise choice.
If, like most British gardeners, you have a large, close-cut lawn, which is likely to be the biggest culprit in terms of unnecessary water demands. Think about reducing its size by widening the adjoining borders and planting them with shrubs or drought-resistant perennials. These need less work and less care than grass does, and look a lot better in a drought. It is also helpful to cultivate a relaxed approach to lawn care; a lawn with a high proportion of clover and other lawn ‘weeds’ will stay greener than one consisting only of grass. Increasing the cutting height in summer will also help – long grass sends down deeper roots and provides more shade for itself. And grass will not die of thirst in this country, so there is no real need to water it in dry periods. If you can cope with the appearance of browning grass for a few weeks, you will save a lot of water – and a lot of work. It will green up again when the rain returns. Areas of hard surfacing are another thing to consider. Tarmac or paving with cemented joints prevents water from draining into the soil and contributes to flooding problems. In a waterwise garden areas of hard surfacing are kept to a minimum, and where hard surfacing is essential, there are permeable options: gravel, bark chippings, cobbles with gaps between them, or ‘porous’ paving, which has gaps for drainage between the pavers.
The second strategy in creating a waterwise garden is to adopt water-efficient gardening techniques. There is a whole range of ways of reducing your plants’ water needs, the most important one being the addition of organic matter to your soil. This will increase the water-retentiveness of light soils and improve the drainage of heavy ones. If a heavy soil is still retaining too much water, you will need to take additional steps, breaking up compacted soil, digging in sand or grit, or constructing drainage channels which draw excess water away from planted areas to a ‘swale’ or ‘soakaway’. Mulching the soil surface will provide an insulating blanket, keeping the soil cool and reducing evaporation, while intelligent plot layout will ensure that drought-sensitive plants are located in shady areas.
Some watering will, of course, still be required; a garden needing no additional water at all would be a very limited one, and crop plants, particularly, do need watering in droughts if they are to give us the yields we want. When you do water, do it thoroughly, so that you soak the soil and encourage your plants to put down deep roots. Water in the early morning, or in the evening, to minimise what is lost to evaporation, and direct water to the base of the specific plants that need it, rather than watering everything indiscriminately. If you have a large garden, consider installing a permanent irrigation system using seep hoses; these deliver water exactly where it is needed, and can be fitted with timers, taps and soil sensors to maximise efficiency.
Once you have reduced your garden’s water needs as far as possible, the third strategy is to supply as much as possible of the remainder from recycled sources. The simplest way of doing this is to harvest rainwater, which is better for your plants than additive-laden tap water in any case. Most keen gardeners already have a water butt, but why only the one? It makes no sense to dispose of ‘excess’ water through the drainage system only to import additional water via the mains. Until you're not using any mains water on the garden, or have no more downpipes, you have scope for more butts. What's more, with a water butt, you can water your garden without falling foul of a hosepipe ban as well as reducing your water bill.
The next step up is a water tank. Above-ground models can accommodate around 1,000 litres (220 gallons) – sufficient, in most gardens, to bridge the gaps between wetter periods or any summer droughts. For larger gardens, and complete water self-sufficiency, there is the option of an underground tank, which can accommodate between 3,000 and 10,000 litres (660 and 2,200 gallons). If full-scale rainwater harvesting is a bridge too far, you will probably need to use some mains water on your garden – but this does not simply mean using extra. Much of household ‘grey’ water, from baths, showers and washing machines, is fit for reuse on the garden. Don't use it directly on edible crops; instead water your ornamental borders with grey water and use the rainwater in your water butts for the vegetable garden. You can siphon the water out of the bath using gravity and a hosepipe, or buy a pump to do the job for you, or you could attach a hosepipe to your washing machine outlet to divert the water from the rinse cycle into the garden. A more elaborate system involves installing two sets of pipes, so that grey water leaves the house separately from black water (sewage). There is also the possibility of creating a garden wetland in which to purify grey water, which would allow you to use it on edible crops.
Creating a waterwise garden is not difficult, and it will become increasingly vital as this century unfolds. The range of possibilities can be bewildering but it is important to see this as an opportunity to choose what is right for you. Few gardeners could put all of the possibilities into practice; fewer still would want to. But whatever kind of gardener you are, there are drought-busting options that will work for you.
Michael Littlewood is a landscape designer and the author of many gardening publications including The Organic Gardener’s Handbook. To order, visit www.ecodesignscape.co.uk or call 01460 75515
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