Should you water plants in sun? Experts warn against this time of day

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 Water plants in sun with sunflowers in it .
Credit: Alamy

If you're wondering should you water plants in sun, then you've come to the right place.

Knowing when to water your plants during hot weather, especially during heatwaves, can be hard, especially since watering your plants at the wrong time can have disastrous consequences.

As well as knowing whether you should water plants in sun, it's also vital you know how often to water a garden in hot weather. Getting these two elements right will ensure that you don't make any gardening mistakes during hot weather.

lavender in border next to galvanised steel watering can
lavender in border next to galvanised steel watering can

Should you water plants in sun?

In short, no you should not water plants in sun.

It is often said that you should not water plants in sun because water droplets on leaves can cause scorching, but this was actually dispelled as a myth by Hungarian scientists in 2010. However, watering plants in sun is still not a good idea. In fact, watering plants in full sun is one of the most common garden watering mistakes.

'It's not advisable to water plants in sun, as the water will just evaporate when watering hot soil during the day,' says Lucie Bradley, co-owner of greenhouse and garden product suppliers, Two Wests & Elliot.

Julian Palphramand, Head of Plants at British Garden Centres seconds this, saying 'Watering your plants in the direct sunlight is generally not advisable as a significant portion of the water will evaporate before it penetrates the soil, making it an inefficient watering method.'

Buys to help your watering

Gardena Micro-Drip-System Drip Irrigation Set Balcony (15 Plants): Starter Set, Ready to Use, Water-Saving Irrigation System, Simple & Flexible Connection Technology (13401-20)
Gardena Micro-Drip-System Drip Irrigation Set Balcony (15 Plants): Starter Set, Ready to Use, Water-Saving Irrigation System, Simple & Flexible Connection Technology (13401-20)
Gardena Micro-Drip-System Drip Irrigation Set Balcony (15 Plants): Starter Set, Ready to Use, Water-Saving Irrigation System, Simple & Flexible Connection Technology (13401-20)
Gardena Micro-Drip-System Drip Irrigation Set Balcony (15 Plants): Starter Set, Ready to Use, Water-Saving Irrigation System, Simple & Flexible Connection Technology (13401-20)

A smart drip system is an easy way to program a watering schedule for the perfect times. This size is great for balconies and small patios.


Verve Red Woodchip Mulch 100l Bag
Verve Red Woodchip Mulch 100l Bag
Verve Red Woodchip Mulch 100l Bag
Verve Red Woodchip Mulch 100l Bag

Good quality mulch will help keep your plants hydrated even in the full glare of the sun.


Hozelock - Watering Timer Sensor Controller : Automatic and Easy Watering With Its Light Sensor, Daily Watering at Sunrise And/or Sunset, Manual Watering Function [2212 0000]
Hozelock - Watering Timer Sensor Controller : Automatic and Easy Watering With Its Light Sensor, Daily Watering at Sunrise And/or Sunset, Manual Watering Function [2212 0000]
Hozelock - Watering Timer Sensor Controller : Automatic and Easy Watering With Its Light Sensor, Daily Watering at Sunrise And/or Sunset, Manual Watering Function [2212 0000]
Hozelock - Watering Timer Sensor Controller : Automatic and Easy Watering With Its Light Sensor, Daily Watering at Sunrise And/or Sunset, Manual Watering Function [2212 0000]

Using a light sensor, this smart device waters your plants at the perfect time.


When should you water plants

Having established that it's not a good idea to water plants in sun – you'll be wondering whether it is better to water plants in the morning or at night.

'We recommend for optimal hydration, it's best to water your plants either early in the morning or late in the evening,' advises Julian Palphramand, Head of Plants at British Garden Centres.

'Morning watering allows plants to absorb moisture before the day’s heat intensifies, while evening watering provides time for the foliage to dry before night and reducing the risk of fungal diseases. Remember to water deeply but infrequently to encourage strong root development and improve your plant's drought resistance.'

watering flowers with watering can
watering flowers with watering can

If you only water plants in sun then the evaporation will likely cause the plants to be underwatered. However, if you water in full sun as well as in the morning and evening, then you run the risk of overwatering your plants in summer.

To avoid this, stick to a regular watering schedule – either morning or evening. Also invest in a good-quality mulch, which you can pick up on Amazon, as this will reduce the amount of evaporation and will help to keep your plants hydrated during the warmer weather.

smart watering system attached to garden tap which is attached to the exterior wall of a house with the garden lawn and house in the background
smart watering system attached to garden tap which is attached to the exterior wall of a house with the garden lawn and house in the background

If you aren't able to water your plants in the morning or evening, then a smart watering irrigation system will prove incredibly useful. These can range from sprinklers or drip systems that work on a timer to smart systems that utilise location and weather data. They are also one of the easiest way to keep plants watered while on holiday.