Watering Plants During Hot Weather – How to Keep Your Garden Healthy

Soaker or leaky hose great for watering in hot weather

Periods of hot weather can put considerable stress on garden plants, vegetables, containers, and newly planted shrubs. While it may seem that simply adding more water is the answer, watering incorrectly can sometimes do more harm than good.

When Should You Water Plants?

The best time to water plants is either:

• Early in the morning before temperatures rise.
• In the evening once the heat of the day has passed.

Avoid watering during the hottest part of the day whenever possible. Not only is a significant amount of water lost through evaporation, but water droplets left on leaves can act like tiny magnifying glasses, focusing the sun’s rays and potentially scorching delicate foliage.

For this reason, it is always preferable to water the soil around the base of the plant rather than spraying water directly onto the leaves.

Give Plants a Good Soaking

One of the most common mistakes gardeners make during hot weather is watering little and often.

A light sprinkle of water rarely penetrates deep enough into the soil to reach the roots. Instead, it encourages shallow rooting, making plants more vulnerable to drought.

It is usually better to:

• Water thoroughly every two to three days.
• Ensure the water soaks deeply into the soil.
• Allow the soil surface to dry slightly before watering again.

This approach encourages plants to develop deeper root systems, making them more resilient during dry spells.

Vegetable crops particularly benefit from deep watering, especially beans, peas, courgettes, tomatoes, pumpkins, and sweetcorn.

Why We Recommend Leaky And Soaker Hoses

One of the most effective watering methods used by the GardenAdvice team is the installation of leaky hoses or seep hoses.

These hoses are laid directly on the soil surface and slowly release water along their length. The benefits include:

• Minimal water loss through evaporation.
• Water delivered directly to the root zone.
• Reduced leaf wetting and lower risk of scorch.
• More efficient use of water during dry periods.

For larger vegetable gardens and borders, leaky hoses are often far more effective than overhead sprinklers.

Cold Water Can Shock Plants

During very hot weather, water straight from the tap can be significantly colder than the surrounding soil.

This sudden temperature difference can temporarily stress plants, particularly those growing in containers and greenhouses.

Where possible, use water from a water butt. Rainwater stored in a butt naturally warms to the surrounding air temperature, making it gentler on plant roots.

A useful approach is to:

1. Water first using water from a water butt.
2. Follow up with additional watering from a hose if required.

This helps reduce temperature shock while ensuring plants receive enough moisture.

Mulching Helps Keep Moisture in the Soil

Mulching is one of the simplest ways to reduce water loss during hot weather.

After watering, apply a mulch around plants to help retain moisture and keep the soil cooler.

Suitable mulches include:

• Bark chips
• Compost
• Well-rotted manure
• Grass clippings (applied thinly)
• Cardboard
• Old carpet sections used temporarily in vegetable gardens

Mulches reduce evaporation, suppress weeds, and help maintain a more consistent soil temperature.

One word of caution: dense mulches can sometimes provide shelter for slugs and snails, so monitor vulnerable plants carefully.

Should You Feed Plants During a Heatwave?

During periods of extreme heat, it is generally best to suspend feeding.

Liquid feeds and fertilisers contain salts that can become concentrated in dry soil. When conditions are very hot, this concentration can sometimes damage or burn plant roots.

Wait until temperatures moderate and the soil is consistently moist before resuming your normal feeding programme.

Key Tips for Watering During Hot Weather

• Water early morning or evening.
• Water the base of plants rather than the leaves.
• Give plants a deep soaking rather than a light sprinkle.
• Consider installing leaky hoses for efficient irrigation.
• Use water butt water where possible to reduce temperature shock.
• Apply mulches to retain moisture.
• Suspend feeding during extreme heat.
• Monitor containers and hanging baskets daily, as they dry out much faster than garden borders.

With the right watering techniques, most garden plants will cope surprisingly well with periods of hot weather and continue to grow strongly throughout the summer.

Need help managing your garden during hot weather? GardenAdvice members can receive personalised watering, feeding, and plant care advice through the MyGardenTeam service and Elena AI gardening assistant.