Garden experts reveal a simple watering tip for your summer containers

As temperatures hot up, how much water do your containers really need? Experts give their opinions on the perfect container watering recipe

person watering pelargoniums in pots using a small watering can
(Image credit: Hornby Whitefoot)

Water is a precious resource and supplies in the US and the UK are under pressure from the effects of climate change, population increase and the need to protect the environment, including lake and river levels for wildlife, warns the Royal Horticultural Society (RHS).

So if you’re looking for ways to keep your stunning summer container ideas looking their best, it makes sense to listen to the experts when they talk about how much, how often and what time of day to water your creations. Add these three ingredients together and you will have the perfect recipe to keep your plants healthy and happy.

But just how much water is the correct amount of water to give your container plants?

plant underneath a decorative garden tap

(Image credit: Hornby Whitefoot)

Container watering tip

When watering plants in containers, the RHS experts recommend adding 10 per cent of the volume of the container at each watering. So for a 10-litre patio pot, add one litre of water. 

Kevin Rodrigues, plant-care expert at GardeningMentor (opens in new tab) says that in drier or drought-prone climates he would always give pots a deep watering: 'You would always want the water to start draining from the drainage holes. This ensures that the moisture in the potting soil will last longer. And it will make the plants more resistant to periods where there is a lack of moisture.'

plants in pots alongside a white watering can

(Image credit: Hornby Whitefoot)

How long to leave between waterings?

There is no simple rule of thumb for how often to water as every plant has different needs – for example, a heavily flowering patio plant in a container in hot sunny weather may need watering daily, even twice, whereas a fern in a garden planter in a shady spot could perhaps go up to a week without seeing the watering can.

'Sticking your finger into the soil to see how dry it is before watering is a good idea,' says Divya Choudhary, gardening expert at consumer comparison website BestViewsReviews (opens in new tab). 'Watering when the soil is already moist can lead to problems such as root rot.'

a trio of containers on a lawn planted with pelargoniums

(Image credit: Pelargoniums for Europe)

Correct time of day

The RHS (opens in new tab) experts say it’s always best to water your container gardening ideas in the morning if possible, as this is when the sun comes up and plants will start to use water. They add that foliage and soil surface is also likely to stay drier for longer than after evening watering, discouraging slugs, snails and mildew diseases.

Jayne Dowle
Jayne Dowle

Jayne Dowle is an award-winning gardening, homes and property writer who writes for publications including Sunday Times Home, Times Bricks & Mortar, Grand Designs, House Beautiful and The Spectator. She was awarded the Garden Journalist of the Year accolade at the Property Press Awards in 2021.