Gardens are not doomed if there is no rainfall and a hosepipe ban says the Royal Horticultural Society (RHS). The charity suggests that by making every drop of water count, by using grey water and using certain watering techniques gardeners will not only play their part in water conservation but will also continue to enjoy their garden this summer.

With the threat of a hosepipe ban the Royal Horticultural Society has some handy hints for gardeners. First it suggests that lawns should be let to go brown. This will not harm the grass as it has dormant buds that will spring to life when the autumn showers arrive. Leaving grass slightly longer will also help to retain soil moisture, reduce wear and tear and keep the lawn greener for longer.

“I know that letting the lawn go brown does not look good but is vital to ensure we use limited water resources correctly. How we water plants is also very important,” says Guy Barter, Head of the RHS Advisory Team. “A lot of people make the fundamental mistake of watering the whole garden. But in most cases only the top part of the soil becomes wet which does no good and is soon lost by evaporation.”

Pond and puddle plants

The advice is to focus watering on the plants that need it by using two techniques called ‘ponding and puddling’ and to water the root zone of the plants and no deeper. Ponding means using banks of soil to hold water around the plant as it soaks into the ground. It can also be useful to sink flower pots beside your larger and more valuable plants so that water can be directly placed near the roots.

Puddling is the placing of new plants into their planting holes and then filling the holes with water several times. The soil is then firmed back against the rootball. This method leaves newly-planted plants with their roots in a mass of moist soil encouraging wide-ranging roots that will stand the plant in good stead later.

Although it is a bit late for this summer the Royal Horticultural Society advises that gardeners should prepare for future low rainfall periods and recommends that gardeners should install rainbutts to collect water over the winter. Adding compost to the soil in the autumn from the garden’s compost heap helps retain moisture the following year. Putting saucers under containers will collect the water that drains through and can be used again. Weeds should be got rid of as they use water that cultivated plants need. Autumn maintenance is key for good lawns; scarify to scratch up dead grass, moss and thatch, and spike or slit the turf to remove compaction and encourage good root growth, finishing off with a winter lawn fertiliser.

Grey water

“Many of our members email us or visit our website to find out what they can do about container-grown plants,” says Guy. “This is difficult as, for example, hanging baskets are placed in a certain position where usually the gardener wants them to stay. In this case we suggest using what is called grey water. This is water collected from washing fruit and vegetables, and hand washing up and less easily, baths, showers and washing machines, but not from dishwashers as this water contains damaging chemicals.”

Grey water varies in quality and usually contains some contaminants. However soil and potting composts are good at filtering out contaminants including soaps and detergents. There should be no problem with short term and small scale use.