The United Kingdom has experienced multiple heatwaves since May, with forecasts suggesting further hot weather. In response to the dry conditions, hosepipe bans have been implemented in various regions, leading many gardeners to seek advice on maintaining their outdoor spaces.
Jo McGarry, a garden design expert at Caragh Nurseries, has provided guidance on how to manage gardens during heatwaves and water restrictions. She emphasizes prioritizing plant health, conserving moisture, and maximizing water usage.
Water Wisely
Even with a hosepipe ban, watering with a watering can may still be permitted, though gardeners should verify local regulations. McGarry recommends watering plants deeply at the base early in the morning. This approach encourages root growth further into the soil, where moisture is more likely to be retained. Priority should be given to newly planted items, shallow-rooted plants, and those that require significant moisture, such as hydrangeas and ferns. Established shrubs and trees are generally more resilient to short dry periods.
Conserving Moisture with Mulch
Applying a layer of mulch can help keep soil cool, reduce evaporation, and suppress weed growth, thereby decreasing the need for frequent watering. Materials like bark, compost, straw, or grass clippings can be spread over damp flower beds. A mulch layer of approximately 5 to 7 centimeters is suggested to help the soil retain moisture longer and protect plant roots from heat. Leaf mould and straw are noted as effective mulches, particularly for vegetable gardens.
Protecting Plants from Sun and Drought
Young plants and vegetables can be particularly vulnerable during extended hot weather. McGarry suggests moving potted plants and hanging baskets to shadier areas of the garden during the hottest parts of the day. Shade netting can also be employed to shield vegetable beds and delicate plants from intense afternoon sun.
Container plants require special attention as pots tend to dry out more quickly than ground beds. Gardeners are advised to check the compost a few centimeters below the surface for dryness and water thoroughly if needed. Checking containers both in the morning and evening is recommended. Grouping pots together can also help create a more humid microclimate.
Rainwater Collection and Plant Stress
Installing a water butt is presented as a valuable long-term investment for collecting rainwater, providing an additional water source during dry spells. Incorporating compost or other organic matter into the soil can also enhance its water-retention capabilities.
During heatwaves, it is advisable to avoid heavy pruning, planting, or feeding, as these activities can increase a plant's water and energy demands. McGarry notes that plants expend significant resources on new growth, and heavy feeding can exacerbate stress. The appearance of brown or yellow grass is often a sign of dormancy rather than death, with lawns expected to recover when cooler, wetter weather returns. If mowing is necessary, it is advised to raise mower blades and cut no more than a third of the grass height to allow longer blades to shade the soil and protect roots. Fertilizing should be postponed until temperatures decrease or rain returns, and the soil should always be watered before feeding.
Weeding is also important, as weeds compete with cultivated plants for limited moisture. Removing small weeds can alleviate pressure on flower beds and vegetable plots. Deep digging in hot, dry soil is discouraged due to increased water loss and potential disturbance to plant roots; hand-pulling or surface cutting of young weeds is suggested instead.