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Guides to water wisely

When and how to water: less often, but better

Published on November 10, 2026

Watering well does not mean watering more: it means giving water at the right time and in the right place. Plants make better use of it, root more deeply and cope better with drought. This advice applies even when watering is allowed.

First, check that it is needed

  • Feel the soil: dig down about fifteen centimetres with a trowel. If the soil is still moist at that depth, watering can wait.
  • Look at the rain forecast: 1 mm of rain is 1 litre of water per square metre. On your commune's page, J'arrose ? answers "No need" when enough rain is expected today or tomorrow.
  • Leave well-established plants alone: trees, shrubs and perennials that have been in place for several years find their water deep down. They only need help in a severe drought.

The right time: early morning, or evening

  • Never in the heat of the day: much of the water evaporates before it reaches the roots. These are also the hours that restriction decrees ban first.
  • Early morning: this is the best time. The soil is cool, evaporation is low, and the plant has water for the day ahead.
  • Evening: this works too, but leaves that stay wet all night encourage diseases and slugs. Water at the foot, without wetting the leaves.

During restrictions, follow the hours set by your commune's decree, shown on its page on J'arrose ?. The guide Understanding restriction levels explains each level.

At the foot, not on the leaves

  • A watering can is the most economical: the water goes exactly where you want it. A hose uses more, and a sprinkler wastes the most: the water evaporates in the air or lands on paths.
  • Aim for the base of the plant, where the roots are. Water poured on the foliage partly evaporates before reaching the soil, and wet leaves are more prone to disease.
  • Targeted systems deliver water slowly at the foot: drip irrigation, soaker hose or ollas.

Less often, but deeply

  • One thorough watering is better than several small ones. A little water every day only wets the surface, which dries straight away, and the roots stay near the top. A good amount from time to time goes down to the roots and pushes them to look for water deeper.
  • Let the surface dry out between waterings.
  • No fixed schedule: the need depends on the weather, the soil and the plant. Clay soil holds water for a long time and needs watering less often, but generously; sandy soil dries out quickly.

Plant by plant

  • Seeds and young plants: they need soil that is always moist. Water the drill before sowing, then keep the surface moist until the seedlings come up.
  • Newly planted trees and shrubs: water them regularly during dry spells in their first year, and for up to three summers for the largest ones.
  • Leafy vegetables (lettuce, chard, cabbage): soil that is moist at all times.
  • Fruiting vegetables (tomatoes, courgettes, aubergines): regular watering during flowering and while the fruit forms. Irregular watering encourages the black patch at the bottom of tomatoes (blossom end rot).
  • Root vegetables (carrots, beetroot, parsnips): less often, before the soil dries out, for example after two weeks without rain.
  • Onions, shallots, leeks: only at planting and during severe droughts.
  • Pots and window boxes: their small volume of soil dries out quickly. Water when the compost is dry 2 to 3 cm below the surface, sometimes every day in summer.
  • Lawn: an established lawn turns yellow in summer but usually greens up again with the autumn rains. The mulching guide gives tips to help it.

Keeping water in the soil

  • Mulch after rain or watering: mulching limits evaporation and keeps the soil moist for much longer.
  • Hoe: "one hoeing is worth two waterings", as the French saying goes. Scratching the top few centimetres of soil breaks the surface crust, through which moisture escapes, and pulls out young weeds.
  • Weed: weeds drink the water meant for your plants.

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