In short
- Push a finger 2–3 cm into the soil, and water only if it is dry down there.
- Water slowly and deeply, and less often, so the roots grow down.
- Water in the morning, never in full sun between 10 a.m. and 4 p.m.
- Use fine drops — a rose on the can, a sprinkler or a drip line.
- Too much water is the most common mistake: roots need air as well as water.
Before you start
You need:
- Something that gives fine drops: a watering can with a rose, a sprinkler, or a drip line.
- Rainwater, if you can collect it. A barrel under a downpipe is often the most sustainable water you have.
In a dry summer, many councils ban garden watering when groundwater runs low. Check your council's website before you water in a dry spell.
Check the soil
- Push a finger into the soil near the roots, two or three centimetres deep. Don't judge by the surface: it dries faster than the soil around the roots.
- If it is dry and crumbly, water.
- If it is cool and moist, wait.
Water
- Water in the morning. It is cool, and the leaves dry during the day, which means less disease.
- Water slowly, with fine drops. A can with a rose, a sprinkler, a drip line, or a gentle stream at the side of the plant all work.
- Water deeply, and less often. A slow, steady flow soaks down to the roots instead of running off.
Avoid heavy drops. They pack the surface into a crust that water runs off instead of soaking in, especially on clay.
Don't water in full sun
Between 10 a.m. and 4 p.m., more water evaporates from soil and leaves than at any other time of day. This is called evapotranspiration. Much of what you pour on at midday is gone before it reaches the roots.
Your soil
- Sandy soil drains quickly, so it needs water more often.
- Clay holds water longer, but its surface seals under heavy watering.
- Compost helps both. Organic matter can hold up to six times its own weight in water.
Log what you do
Log each watering with Log watering. When you check and the soil is still moist, use Log soil check instead.
The app combines both with the weather. For a garden with its location set, it tells you when the soil may be getting dry, so you don't have to keep track yourself.
Why it works
Roots need air as much as they need water. Soil full of water has no air left in it, and the roots suffocate. That is why watering too much, too often, is the most common mistake in vegetable gardens.
Roots grow where the water is. Water a little and often, and they stay near the surface, which dries out first in a dry spell. Water deeply and less often, and they follow the water down to where the moisture lasts.