In hot weather, water early in the morning, directly at the roots, and rather rarely but deeply: enough for the soil to be moist down to about 15 centimetres. Then let the top layer of soil dry out again. Frequent, short sprinkling only wets the surface, the water evaporates and the roots stay shallow.
Why in the morning and not at midday?
Early in the morning the soil is cool and evaporation is low. The plant then has the water available when it needs it, in the heat of the day. At midday much of it evaporates before it reaches the roots. Watering in the evening is the second-best choice, but leaves that stay wet overnight encourage fungal diseases and slugs.
How much is enough?
The spade test gives you a clue: after watering, dig down a hand’s depth in one spot. If the soil is still dry there, it was not enough. A generous soak every few days is better than a little every day: that way the roots grow down to where the soil stays moist for longer. Sandy soils dry out faster and need water more often than clay soils.
Who comes first in hot weather?
- Newly planted trees, shrubs and perennials whose roots do not yet reach deep.
- Vegetables and soft fruit, especially tomatoes, cucumbers and courgettes while the fruit is forming.
- Plants in pots and containers, which dry out in a short time.
- An established lawn, on the other hand, may turn brown: it is only resting and recovers after the next rain.
How do I keep the water in the soil?
A mulch of grass clippings, leaves or composted bark shades the soil and clearly reduces evaporation. Briefly loosen crusted soil before watering so the water soaks in instead of running off. Rainwater from the butt saves mains water and suits lime-sensitive plants such as rhododendrons better.
Do you even need to water after a thunderstorm? That depends on the amount of rain, the soil and the plant. The page Maluna features describes how Maluna takes the weather into account here.