New plantings, containers and vegetables need watering; established shrubs and lawns generally do not. A thorough soak at the base of the plant, morning or evening, works better than a daily sprinkle.
Water butts, drip irrigation and mulch cut the use of mains water, and watering cans remain legal during a hosepipe ban.
Most established garden plants in Britain and northern Europe survive on rainfall for most of the year. Watering matters for a limited list of plants at particular times, and doing it well uses far less water than a sprinkler left running.
Established lawns do not need watering. Grass turns brown in a dry summer and recovers within weeks of rain returning, as described under looking after a lawn.
Watering in the early morning or the evening loses least to evaporation. Water is directed at the soil around the base of the plant, not over the leaves. A thorough soak once or twice a week sends roots deeper than a light daily sprinkle, which wets only the surface and encourages shallow rooting.
The test of whether water is needed is the soil a few centimetres down, not the surface. Wilting in the heat of the afternoon that has recovered by morning is not a sign of drought.
A water butt connected to a downpipe by a diverter fills from the roof of a house, garage, shed or greenhouse. Several can be linked in a row. A lid keeps out light, leaves, mosquitoes and children, and a stand raises the tap high enough for a watering can. Many water companies and councils run schemes supplying butts to residents.
Household grey water from baths, showers and washing-up can be used on ornamental plants in a dry spell. It is applied within a day, since it turns foul if kept, and is not used on salads or other crops eaten raw.
A litre of water weighs a kilogram, so a full 10-litre can is a substantial load; two smaller cans, one in each hand, are easier to carry than one large one. Plastic cans are light and do not rust, while galvanised steel lasts longer if emptied after use. A long spout improves reach and balance. The detachable sprinkler head, called a rose, is turned upwards for a fine shower on seedlings and removed for watering at the base of established plants. A small can with a narrow spout suits houseplants and greenhouse trays.
A hose needs to reach the furthest point of the garden without strain. Reinforced, multi-layer hoses resist kinking and last longer than thin single-layer ones; a reel or wall bracket keeps the hose off the ground and out of sunlight, which makes it brittle. A trigger nozzle that shuts off when released stops water running between plants.
In the United Kingdom an outside tap must be fitted with a double check valve, which stops water from the hose being drawn back into the mains supply.
Drip irrigation delivers water slowly to the soil through small emitters set along a narrow pipe, one to each plant or pot. Porous or soaker hose, laid along a row or hedge and covered with mulch, seeps along its whole length. Both use much less water than a sprinkler, which throws several hundred litres an hour over paths and foliage as well as soil.
A simple system consists of a pressure reducer at the tap, a supply pipe and the drip lines, and is assembled without tools. A timer on the tap runs it in the early morning, and some models skip watering after rain. Systems are drained or brought in before hard frost.
In a drought, water companies in the United Kingdom can impose a temporary use ban, generally known as a hosepipe ban. It prohibits the use of a hose, sprinkler or other equipment connected to the mains for watering gardens, washing cars, cleaning paths and filling pools and ponds. Breaking a ban is an offence that can lead to a fine.
Watering cans filled from the tap remain legal, and the ban does not cover rainwater from a butt. Exceptions differ between companies, but commonly include Blue Badge holders, drip irrigation fitted with a timer and pressure reducer, and newly laid turf for a limited period. Each company publishes its own rules when a ban is announced.