Too much or too little water can wreak havoc on the health of plants, but it’s not just the frequency of watering gardeners should pay attention to. According to experts, the time of day plants are watered is just as important.
Sarah Dixonm a spokesperson for Hozelocks explained: “Sometimes extreme summer temperatures leave plants struggling to survive.
“Many plants can withstand temperatures up to the high 20˚C mark before they begin to suffer. By watering your plants at the right time of day, you can help them survive a heatwave and continue to flourish.”
What is the best time of day to water plants?
Kate Turner, Miracle-Gro’s Gardening Guru advised: “I always recommend watering in the morning when asked when is the best time to water plants.
“It’s obviously a lot cooler in the early hours of the day, so the water has more of a chance to work its magic, without being evaporated by the heat of the day. This ensures the water gets down to the roots, helping the plant stay hydrated.”
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As for why the start of the day is preferred, Josh Papworth from Haws, the oldest manufacturer of watering cans in the world explained how the “cooler temperature in the morning means the water has a chance to get down to the roots, rather than evaporating in the heat of the sun”.
This means “plants have a reserve of water to use throughout the day so that they don’t end up parched”.
If morning watering doesn’t fit in with your schedule, then the early evening is the next best option – but only once the peak heat of the sun has gone.
The only downside to watering in the evening is damp leaves and soil can provide the perfect conditions for mildew, which, in turn, encourage slugs and snails.
How much water do plants need?
During hot weather, it may be tempting to water plants just enough to keep the soil damp. But shallow surface watering discourages deep root development.
Therefore, gardeners should opt for a less frequent watering routine that thoroughly saturates the soil as this encourages the plant’s roots to reach deep for residual water, even when the surface of the soil appears dry.
The standard rule of thumb is to give flowers and vegetables the equivalent of one inch of water per week – and as much as double that amount in the peak of summer.
How to check if plants need water?
Garden plants can suffer when the soil dries out, but they also don’t like “wet feet”, meaning they suffer if roots are sitting in water and not getting sufficient oxygen.
On a hot, windy day, the soil’s surface may appear dry, but beneath, the soil is moist, so it’s essential to perform a quick check to ensure the plant is not overwatered.
Keep a wooden plant label – similar to a lollipop stick’ – and insert it a few inches into garden soil, pull it out and check it. Moist soil will stick to stick, but if it comes out clean, the soil is dry, and it’s time to water.
Do you have to water plants after it’s rained?
As for whether you should water plants after rainfall, Gardening Etc says “the best time to water [plants] is after it’s rained when the soil is softened and more receptive to a good soaking”.
The experts added: “Extra water after a downpour tops up the rainfall, so it can penetrate further down into the soil. This is a great way to build up moisture around plant roots.”
To help plants retain moisture after watering, flower beds can be topped with bark or peat-free enriched compost.
A sprinkler or water irrigation system can also be installed, with auto timers for the water to automatically come on in the morning or evening, thus reducing the need for gardeners to physically water plants themselves.