How to use water wisely
Water is a precious resource. Organic growers are perhaps the best on earth at using water efficiently and effectively. Here are some ideas which will help you water wisely:
- Good watering techniques
- How to collect and store water
- Long-term ways to reduce your garden’s thirst for water
- Always water the soil, not the plant. And make sure the water goes deep. Give the soil a good soaking every few days rather than just wetting the surface. This will encourage the plant from a young age to put down deep roots away from the surface of the soil, which dries out more quickly.
- Water in the evening, after the sun has gone down. Or in the early morning when the soil is cool. Watering in the heat of the day will mean much water is lost to evaporation.
- Use a watering can. It directs water exactly where you need it, on the soil not the plant. Hosepipes and sprinklers can waste water. Seedlings, plants in pots, and other greenhouse plants can be watered more gently using a drip irrigation method – which provides a minimal constant water supply. Search online at The Organic Gardening Catalogue
- Apply mulch around your plants after watering. A covering of grass cuttings, leafmould, straw - even cardboard - after you have watered will keep the moisture in. If you grow in pots, use gravel on top to stop the soil transpiration.
- Going away for a few days? Try this handy clay pot watering. Take an unglazed clay pot and seal the hole in the bottom so water can’t escape. You also need a lid to the pot – make your own from wood or sturdy plastic recycled from a container. Sink the pot in the ground, fill with water and cover. Plant seedlings around the pot. The gradual escape of moisture should last for 10 days before needing a top up.
What NOT to do! Don’t water lawns, they always recover. And avoid using a sprinkler – too much water is lost in the air and doesn’t penetrate straight to the roots.
- Make sure all your down pipes have water butts connected. Even the greenhouse and garden shed. If you have room, install two butts, linked together, to catch overflow. Some down pipes are open at the drain end, so you can fix a diverter into a water hose, using a combination of a cut-off large plastic milk container and plastic pipe connections.
- Can you improvise and recycle containers? Old central heating tanks and any other rigid plastic containers (well rinsed and washed out before use).
- Keep water containers covered to prevent algae and insects colonising the water.
- Keep all rinsing water – washing vegetables and salads will collect a surprising amount by the end of the day.
Using grey water from baths and washing up is an excellent way of recycling water. Here are some important tips:
- Make sure you don’t use too much soap/shampoo. What's good for stripping fat from dishes isn't good for soil life.
- Use ecologically friendly detergents. Water that has washing powder or washing up liquid in it can be used, but infrequently – this is because the modern detergents have enzymes and phosphates in them which, if used in concentration, an actually harm the plants. The water is also often surprisingly greasy by the end of a washing up session – this grease may affect soil life and particles.
- Avoid using grey water continually on the same patch of ground or pot. Residues can build up in the soil.
- Use the water straight away. Stored grey water can harbour legionnaires disease.
- Don’t use grey water on seeds. They are prone to ‘damping off’, a technical term which covers a variety of fungal infections. Use fresh tap water instead.
- Hand pumps for syphoning off clean bath water are available.
- Reducing your garden’s thirst for water
With simple planning, there are a number of ways to significantly reduce how much water your garden will need. Here are our recommendations.
- Invest in your soil by adding homemade compost. Wherever you grow - in pots, back garden or an allotment - this bulky material not only adds nutrients but also improves the soil structure so that light sandy soils will retain water better, and clay soils will become less dense. Add compost in the spring, about a barrowload every 5m2.
- Avoid bare soil. It will dry out more quickly if exposed to the sun. Plant densely, so foliage will cover the soil and protect against moisture loss.
- Protect your plants. Wind can dry soil, as much as sun. A windbreak will give shelter over a distance of six times its height. Hedges and trellis are perfect, providing shelter for birds and insects as well as the ground beyond.
If your growing area is prone to dryness, choose plants which relish dry conditions so you can concentrate your precious water resource on the water hungry annuals such as vegetables and salads. Here is a list of drought tolerant plants:
- Succulents such as sedums, sempervivums, yucca
- Hairy plants such as poppies, knapweed, asters, salvias, verbascums, stachys
- Aromatic herbs such as lavender, rosemary, thyme, sage
- Silver leaved plants such as achillea, wormwood, lychnis, cystus, santolina