Should outdoor plants be watered every day in hot weather? Horticultural experts reveal all

Staying hydrated during hot weather is vital for all living things, including outdoor plants. Therefore, watering your garden plants more frequently during the hot weather is essential, but how much is enough?

While we can experience the odd rain shower during the warmer months, you still need to give your precious plants a helping hand to ensure they thrive throughout persistent spells of hot weather. This is particularly important if you have some of the best patio container plants in your outdoor space.

Below, you'll find useful advice from our team of trusted gardening professionals to ascertain the right frequency for watering your plot when it's hot, including tips on soil types, the difference in types of plants and the best time of day to carry out the job to ensure maximum absorbency.

Should outdoor plants be watered every day in hot weather?

"You should water outdoor plants more often in hot weather, but it depends on factors like soil type, plant maturity, and location," advises professional gardener Jane Dobbs.

If you've recently planted flower seeds in April, take note: "Young plants need daily watering in hot weather to keep their roots moist, especially if the soil dries out fast due to the temperature."

"However, for established plants, watering every 2-3 days is usually enough in hot weather, 4-5 days for normal garden soil, and 6-8 days for clay soil," says Jane.

Our w&h resident garden expert Kayleigh Dray offers her helpful insight: "Plants will need to be watered more regularly in hot weather, but not necessarily every day – unless they’re in a container or a wallside border that restricts their root growth.

Jane Dobbs

Gardening is Jane's passion, having built and maintained stunning outdoor spaces for over a decade. Taking care of all the garden projects at Allans' Gardeners is her responsibility as lead gardener. A wide range of horticultural practices come into play in Jane's work, from landscape design to plant and lawn care.

"A good rule of thumb is to push your finger into the soil until it hits your knuckles: if it’s dry all or most of the way through, they need a good drink. Make sure you water deeply at the roots."

Ever conscious of the need to follow sustainable garden ideas, Kayleigh adds: "Be sure to use rainwater (or grey water, if it’s been very dry out) where you can." With the right rainscaping ideas you can greatly reduce your water usage, even throughout the summer months.

And speaking of collecting rain, how does a downpour affect watering outdoor plants in hot weather? A lot of us will be wondering this because, as we know from this week, we still experience bursts of rain in the spring and summer months.

"Definitely no need to water after rain," advises Jane. "Heavy rain typically provides more than enough moisture for the soil, often soaking it deeper than regular watering. Additional watering can lead to waterlogging, root rot, or fungal problems. To be sure, check the soil about 1-2 cm down. If it’s still moist, skip the watering."

When should you water plants in hot weather?

Similar to watering grass seed, timing is everything to ensure maximum results and better efficiency, particularly in hot weather. You don't want to water outdoor plants when temperatures are already high because a lot of the water evaporates before it reaches the roots.

"If there’s been a bout of hot weather, it’s always best to water plants in the early mornings, as this will give them plenty of time to soak up all the water they need before the sun evaporates it all," Kayleigh explains.

"Otherwise, you can water in the early evening, although this can put your plant babies at risk of attack from slugs, snails, and fungal growths," she warns. "Whatever you do, don’t do it in the heat of the day: it’s a waste of water."

Jane agrees, saying: "Early morning is best for watering plants because the temperatures are cooler, which reduces evaporation and allows the water to soak into the soil."

"Late evening watering is the next best thing if morning isn't possible, but don't overwater and don't get water on leaves to prevent fungal diseases."

Tips for watering outdoor plants in hot weather

To ensure your hot weather watering efforts are being done expertly we asked Jane to share her professional tips for dealing with outdoor plants during hot weather...

• Deep, less frequent watering is better than shallow, frequent watering. "Plants have a better chance of surviving drought with deep watering."
• Use mulch. 'You can mulch around plants to prevent evaporation and to keep the soil moist." If you are not familiar with the process, you can discover what mulching is and how best to use it with our helpful guide.
• Reposition potted plants. "To prevent soil from drying out too quickly during the hotter parts of the day, move potted plants to the shade during these hours.
• Utilise helpful watering methods. "Add water-retention granules to soil or pots to keep moisture levels high."

"The most vulnerable plants to dehydration are seedlings and transplants," Jane warns. So, make extra watering a priority if one of your essential May gardening jobs is establishing young plants that are most at risk.