Is it better to water plants in the morning or the evening?

Morning, in most situations — but the reasoning matters more than the rule, because the trade-offs change with climate and with what you are growing.

Morning watering has three advantages. The foliage dries during the day, which matters because leaves that stay wet overnight are far more susceptible to fungal diseases including blight, mildew and black spot. The plant has water available before the heat of the day, when demand peaks. And less is lost to evaporation than watering at midday, because soil and air are still cool.

Evening watering keeps more water in the soil, since almost nothing evaporates overnight, so it is genuinely more efficient in hot dry climates. The cost is prolonged leaf wetness and damp soil surfaces through the night, which favours both fungal disease and slugs. If you water in the evening, water the soil directly and keep foliage dry.

Midday is the worst option in open ground, mostly because a large share evaporates before it reaches the roots. The common claim that water droplets act as lenses and scorch leaves has little support for normal garden conditions, so do not let it stop you rescuing a badly wilting plant at noon.

Two details matter more than timing. Water deeply and less often rather than lightly and daily — shallow watering encourages shallow roots that dry out fast. And direct water at the base of the plant rather than over the top, which both reduces disease and puts the water where roots are.

Containers are the exception to all of this. In hot weather they may genuinely need water twice a day regardless of schedule.