Watering seems straightforward — you pick up a hose and water. But the techniques of summer watering hide many common errors that lead to fungal diseases, cracked fruit or unnecessary water consumption. Getting watering right is fundamental to a successful summer in the garden.
When to water
The ideal time for summer watering is early morning, ideally between 5 and 8 o'clock. The soil is cool after the night, water doesn't evaporate and plants have all day to absorb moisture. If mornings don't work, water in the late afternoon after 6pm.
Never water during the midday heat. Water evaporates instantly from the surface and barely reaches the roots. Moreover, water droplets on leaves can act as magnifying glasses in sharp sunlight and cause scorch marks.
How much water
The basic principle: less often but thoroughly. Light surface sprinkling moistens only the top few centimetres and roots grow shallow, chasing the surface moisture rather than striking deep. Thorough watering — where water penetrates 15–20 cm down — encourages deep rooting and makes plants drought-resistant.
A rough guide for vegetables: 20–30 litres per square metre at each watering session. In hot summer weather, water every other day; in extreme heat, daily. Leafy vegetables (lettuce, spinach) need more frequent watering; root vegetables (carrots, parsley) need less.
How to water
At the roots, not on the leaves
Always water at the base of the plant, at root level. Wet leaves are a breeding ground for fungal diseases — blight on tomatoes, powdery mildew on cucumbers. If you use a sprinkler attachment, adjust it so water lands on the soil, not on the foliage.
Mulching
Mulch is the gardener's best friend in summer. A 5–10 cm layer of straw, grass clippings, bark or compost around plants reduces evaporation by 50–70 percent. Mulch also suppresses weeds and, as it breaks down, adds nutrients. Always apply mulch after thorough watering to lock the moisture in beneath the layer.
Drip irrigation
Investing in drip irrigation pays for itself. Lay soaker hoses or drip lines along the rows and connect them to a tap with a timer. Water goes directly to the roots, minimal evaporation occurs and you can water consistently even when you're away on holiday. The return on investment is typically achieved within a single season through water savings and improved yields.
Individual crop requirements
Tomatoes
Water regularly and evenly. Alternating drought and waterlogging causes fruit cracking and blossom end rot. Ideally water every other day, daily in hot weather. Always at the roots. During the ripening phase, reduce watering slightly — the fruit will be more flavourful.
Cucumbers and courgettes
Cucurbit family crops have large leaves and high transpiration rates. They need the most water of all vegetable crops. Water daily in summer; in extreme heat even twice a day. Water shortage causes cucumbers to taste bitter.
Lettuce and leafy vegetables
Regular, moderate watering. Lettuce has shallow roots and bolts quickly without adequate moisture. In hot summer weather, consider shading with fleece or growing in partial shade.
Carrots and root vegetables
After germination, keep moisture even; later water less frequently. Overwatering causes roots to crack and rot. Carrots are relatively drought-tolerant once established.
Fruit trees
Established trees generally don't need watering because of their deep root systems. Young trees (under 3 years old) and trees during drought need watering once a week with 30–50 litres. Pour the water into a shallow ring around the trunk, not directly onto the trunk itself.
Saving water
Rainwater is ideal for the garden — it's soft, at the right temperature and free. Investing in a water butt (500–1,000 litres) pays back within one season. Position it under a downpipe from your roof and connect a hose or pump to it.
Good summer watering is a skill you develop gradually. Observe your plants — they'll tell you when they're thirsty. Wilting leaves in the afternoon heat is normal; if leaves haven't recovered by next morning, that's the signal to water.