In the heatwave, make sure you're watering your plants at the right time of day

Published: May 26, 2026 at 11:46 am

High noon, the cool of the morning or the shade of the evening; there are many theories about the best time of day to water your plants. And in a heatwave it'll pay to get it right.

According to Stuart Thompson, senior lecturer in plant biochemistry at the University of Westminster, plants go through their own weight in water on a sunny day. He explains that plants that are not in pots will benefit most from being watered morning or evening, when droplets have time to soak down into the soil .

The common belief that water drops act like magnifying glasses and scorch leaves if they are wet is incorrect, according to Thompson, with the exception of leaves with hairs which could hold drops far enough away from the leaf for sun rays to be focused on the leaf surface.…