How to cope with drought
By Alan Titchmarsh

It's only just April and hosepipe bans are the topic of many a gardener's conversation. After two of the driest winters on record, water authorities are preparing the nation for water shortages this summer. So, what can we gardener's do about it? Well, there's a range of measures you can take to reduce your garden's need for water as well as techniques you can employ to conserve the water you have.

Saving water
You can collect water from down pipes on your house, garage and greenhouse by plumbing in a waterbutt or two. You can make the process automatic by using one of the handy water diverter kits. Bear in mind that it needs to rain to keep the butts topped up and a typical butt may hold 150 litres of water which would keep a row of tomatoes or pair of growing bags watered for about six weeks. So you will need to target the water you save carefully, or install a battery of butts to provide for all the water needs of your garden. Another option is to recycle so called 'grey-water' from your house. This is the water that's been used for washing-up, baths or in the washing machine. You will have to wait for it to cool and transferring it to the right part of the garden can be tricky. Ironically, the easiest method is to use a hose to siphon the water to where it is needed, but this may in itself fall foul of the hosepipe ban! There are several problems associated with 'grey-water' in the garden. The water inevitably will contain soaps and detergents that are generally alkaline, so not suitable for acid-loving plants such as rhododendrons and camellias. Some plants are susceptible to the salts and chemicals 'grey-water' contains, so I wouldn't advise using it on seedlings, rooting cuttings or very young plants. Avoid applying it to the vegetable garden, too. Also, bear in mind that on clay soil the soaps can increase the strength of the bonds between the tiny particles, making the soil seem stickier and harder to work.

Choosing the right plants
If you are starting a new garden from scratch, are planting a new border, or just planning this year's container displays, it makes sense to choose drought-tolerant plants. Shrubs, such as buddleja, cotoneaster, cistus, elaeagnus, lavender, Philadelphus microphyllus, Rosa rugosa, Rosa rubrifolia and common lilac varieties all have a deserved reputation for tolerating water shortages. Similarly, herbaceous plants, such as achillea, artemisia, some euphorbias, nepeta, santolina and stachys as well as rock plants like aubrieta, campanula and sempervivum can cope well in dry soil. Bedding plants that recover well from periods of drought include felicia, gazania, pelargonium, helichrysum, marguerites, mesembryanthemum, nicotiana, ostespurmum, petunia and portulaca. Useful to know if you've suffered losses because of erratic watering in the past.

Planting correctly
Even drought-tolerant plants will need to be watered regularly until they are well established. Before planting make sure you add plenty of well-rotted manure or garden compost to the soil and planting hole to increase the water-holding capacity of the soil. If the soil is dry at planting time, one useful technique to try is puddling-in. Simply, soak the plant in its pot beforehand as normal, then fill the planting hole with water too. Plop the soaked rootball into the flooded planting hole and top up with soil. If the sun is strong, shade all new plants with netting to prevent them wilting. Ideally, plant as the sun goes down in the evening to give the new plants a respite before the sun rises the following morning. After planting it's also a good idea to cover the soil with a generous layer of loose organic mulch such as composted bark chippings or well-rotted garden compost. This will not only prevent moisture evaporating from the soil's surface, but will also reduced the need for weeding that inevitably disturbs the soil, exposing more precious damp soil to the drying effects of the sun. Gravel and pebbles make a longer-lasting decorative mulch. If you are on a tight budget, you can mulch effectively with other materials too, such as black polythene, lawn clippings or pieces of old carpet, but these can look unsightly and are best used at the back of beds and borders.

Watering responsibly
Not all plants or parts of the garden need to be watered even during a prolonged drought. The biggest waste of water in UK gardens is on the lawn. Soaking it once a week may keep the grass green and growing vigorously, but it is a reckless misuse of this precious resource. Grass is well-adapted to coping with drought, so allow it to dry and turn brown during the summer months. It will soon green-up again with the autumn rains. Brown grass also doesn't need mowing, so you'll save time and effort too.
   Some plants will need regular watering to survive (see below), but even here you can reduce the amount of water you use by applying it accurately around the base of the plant so that only the root zone is soaked. Try creating a ridge of soil around individual plants to form a circular barrier that will prevent the water running off before it's had time to soak in. Or sink an empty pot rim-deep into the soil alongside thirsty plants so that you can fill this with water instead. Rows of plants are easier to water using special leaky hoses hidden under the surface of the soil, or you could drill holes in a piece of guttering and use this instead - unless, of course, your local authority has banned these watering aids too! For deeper-rooting plants such as new trees and shrubs, sink a 30cm (12in) piece of drilled drainpipe alongside the rootball so that the water is delivered exactly where it is needed. Make sure you water thoroughly once a week, rather than sprinkling on the water in smaller amounts more often. Thorough watering will ensure the soil is soaked right down to the root-zone and since the surface will be wetted less often there will be less water lost through evaporation. For the same reason, it's also worth watering in the evening, rather than at other times of the day.

Regular weeding
Although disturbing the soil when weeding brings damp soil to the surface, more water is removed by the weeds if they are left to grow and set seed. The secret is to hoe regularly, removing weeds as seedlings. Some gardener's swear that by having a loose dry surface layer to the soil creates a 'dust mulch' that helps prevent moisture being lost from the soil underneath - but I think the jury's still out on that one.

What needs watering?

  • All new plants - water thoroughly, once a week throughout a summer drought and as necessary thereafter.
  • Container plants - water routinely every day during the summer.
  • Bog gardens - keep moist at all times.
  • Leafy vegetable crops - need regular watering to keep producing succulent leaves and stems.
  • Vegetable crops with pods or tubers - water is essential when pods or tubers are swelling.
  • Fruiting trees, bushes and canes - water is essential when fruits are swelling.

Alan's tip

Wetting dry compost
If a peat-based compost in a container has been allowed to dry out it can be very difficult to re-wet. To overcome this problem, either stand the plant in a bowl of water for 24 hours until the compost soaks up the water, or try throwing a handful of ice-blocks on the top of the rootball. The ice-blocks will slowly melt soaking the surface layer of the compost, so that it readily absorbs water once more. Alternatively, use 'grey-water' left over from the washing-up because the detergent will help the water soak into the dry compost.

Happy gardening!