Watering in a hot summer: when, how much and with what

In July and August people make three watering mistakes, and all three can be fixed without spending anything.

When

In the morning, ideally before seven. The plant has the whole day to use the water and the leaves dry by evening. Watering at night leaves foliage wet until morning, which is an invitation to fungal disease.

How much

Better once properly than three times a little. Shallow frequent watering keeps roots near the surface, where they dry out on the first hot day. Ten litres per square metre every three days beats two litres a day for most beds.

With what

Water from a barrel is at ambient temperature and plants take it better than cold tap water. Drip irrigation pays off for vegetables and in planters, where evaporation wins; on a lawn it is pointless.

Mulch

Five centimetres of mown grass or wood chips cuts evaporation roughly in half. It is the cheapest thing you can do for watering.