How To Prevent Potted Plants From Drying Out In A Heatwave

This week, a red weather warning is in place across parts of the UK due to extreme heat.

Gardeners know this can spell disaster for some plants – especially potted plants, which you should move into the shade (if at all possible) during the soaring temperatures.

Potted plants have shallower soil and hold less moisture.

This is particularly true, the University of California’s Agricultural and Natural Resources (UC) site explained, for some pots over others.

UC’s site reads: “Terracotta isn’t the best when trying to keep your plant alive during a heatwave. It dries out quickly and so does the water you applied.”

That’s because terracotta is porous, meaning it absorbs and wicks away water quite quickly.

In “normal” UK weather conditions, that’s not a problem – in fact it can prevent plants like basil from becoming waterlogged and experiencing conditions such as root rot.

But when it’s really hot and dry outside, Homes & Gardens explained, it might cause more of an issue, especially if it’s unsealed (coated with a water-resistant substance).

“It allows for quick evaporation, meaning plants will dry out much more quickly,” the publication said.

Additionally, UC said, “plants often come home from the store in thin, black plastic pots that also heat up significantly in the sun”.

This is especially likely if you have a smaller pot, as these retain less water.

Step one is to keep an eye on the weather forecast and act preemptively. Watering your plants deeply in the morning of a hot day can go a long way to keeping them safe – and this is especially true of potted plants (terracotta and thin, dark plastic ones especially).

Mulching might help, as can adding self-watering tools.

If you can move terracotta or thin, dark plastic pots to a shady area, do so “until you can repot a plant into another safer container on a cloudy day,” UC continued.

“Pick big, thick plastic or heavy ceramic pots with decent-sized drainage holes” instead.