As the UK endures relentless heatwave after heatwave, the scorching and parched conditions are taking a significant toll on gardens and plants alike. More than two-thirds of England and the entirety of Wales are now experiencing drought, resulting in hosepipe bans (also referred to as Temporary Use Bans) being imposed by nine water companies across England and Wales.
The Common Plant Watering Mistake Everyone Makes
While it might appear that the ideal time to water a parched lawn or thirsty plants is during the height of the day's heat, this is actually far from the truth. The RHS explains: "Timing makes a big difference to how effectively plants use water." The guidance is clear: "Avoid watering in the heat of the day - much of the water evaporates before reaching the roots."
Watering plants in direct sunlight during the hottest part of the day is inadvisable, as the majority of the water will evaporate before it even reaches the plant's roots. Plants are unable to absorb the necessary level of moisture through this method, making it far less effective for their wellbeing.
The Optimal Time to Water
The optimal time to water your garden plants and lawns is early in the morning, while there's still a whiff of coolness in the air. RHS advice clearly states: "Watering early in the morning is the best time. There will be less evaporation, and plants can use the water through the day." While watering in the evening is also acceptable, there is one thing to be mindful of. The RHS warns: "Evening watering is acceptable, but damp leaves overnight can encourage pests and fungal diseases."
Speaking to Gardens Illustrated, Stuart Thompson, senior lecturer in plant biochemistry at the University of Westminster, reveals that plants have a tendency to consume their own weight in water on a hot and sunny day. Thompson makes a further distinction for UK gardeners, explaining that plants which are not in pots and planters specifically will benefit most from being watered in the morning or evening. This is because the water droplets will have sufficient time to properly seep down into the soil and reach the actual roots of the plant.
Tips for Drought-Tolerant Plants and Lawns
The RHS offers a helpful tip to make your plants 'drought athletes': "Deep, occasional watering encourages deep roots and drought-tolerant plants. Train your plants to be 'drought athletes.'" Echoing this advice, Matt J Adams, founder and lead gardener at The Relentless Gardener, shares the most effective way to water yellowing, parched lawns in this heat: "Water smarter, not harder. A thorough soak every few days is much more beneficial than a light sprinkle every evening. Deep watering encourages the roots to grow further into the soil, making the lawn better equipped to cope with the next dry spell. Water early in the morning or later in the evening to minimise evaporation and avoid scorching the grass."
