Gardening Through Heat and Drought

Watering & Weather

Jul 22

Periods of unusual heat and limited rainfall place both plants and gardeners under pressure. Crops lose water more quickly, soil dries faster and available water may need to be carefully prioritised.

Heat and drought are related but not identical. A short spell of extreme heat can damage plants even when the soil contains moisture, while a long dry period can gradually exhaust water reserves without exceptionally high temperatures.

The best response depends on your normal climate, soil, water supply and the crops being grown.

Understand Heat Stress

Plants cool themselves by releasing water through their leaves. During very hot, dry or windy weather, they may lose water faster than their roots can replace it.

Leaves may curl, droop or develop scorched edges. Flowers can fall, pollination may be reduced and fruit may stop developing normally. Pale patches can appear on fruit exposed suddenly to intense sunlight.

Some plants wilt temporarily during the hottest part of the day and recover as temperatures fall. Check the soil before watering because midday wilting alone does not prove that the root zone is dry.

Prepare Before Extreme Heat Arrives

Check local weather information regularly during the growing season. If exceptional heat is forecast, water vulnerable areas before the most intense conditions arrive.

Early preparation allows moisture to soak into the root zone. It is more effective than repeatedly wetting the surface after plants are already under severe stress.

Your Growing Companion provides location-aware weather information that can help you anticipate heat and sudden changes. Use it alongside local forecasts and observations from your own garden.

Decide Which Plants Need Priority

When time or water is limited, not every part of the garden should receive equal attention.

Give priority to:

Newly sown areas
Young seedlings
Recent transplants
Containers and hanging baskets
Shallow-rooted crops
Plants flowering or forming fruit
Greenhouse crops
Newly planted trees, shrubs and perennials

Established trees, shrubs and deep-rooted perennial plants may be able to use water stored deeper in the ground. Check their condition and soil before watering automatically.

It is usually better to water a smaller priority area thoroughly than to sprinkle the entire garden without reaching the roots.

Water Deeply and Accurately

Direct water towards the root zone and apply it slowly enough to soak into the soil.

Frequent shallow watering encourages roots to remain near the surface, where they are more vulnerable to heat and drying. A deeper application followed by checking the soil is generally more useful for established plants.

Sandy soil may need more frequent attention because water drains quickly. Clay soil should be watered slowly or in stages so that water can enter without running off.

Very dry soil can initially repel water. Apply a small amount, allow it to soak in and then return with a deeper watering.

Choose the Most Effective Time

Early morning is generally the best time to water during hot weather. Evaporation is lower, and plants can take up moisture before the hottest part of the day.

Evening watering can also be effective in hot, dry climates. Direct water towards the soil and consider local humidity and disease risk before routinely wetting foliage late in the day.

Avoid waiting for a preferred time if a plant is genuinely suffering from a lack of water. Severe water stress should be addressed when it is discovered.

Cover the Soil

Bare soil heats and dries rapidly. A layer of compost, straw, grass clippings, leaves, chop-and-drop material or another suitable mulch reduces direct evaporation and protects the surface.

Apply mulch to moist soil whenever possible. Leave a small space around vulnerable stems and do not create thick, wet piles that restrict airflow.

Mulch depth and material should suit the climate. A substantial layer may be valuable during a hot, dry summer, while the same layer could keep soil excessively cold and wet in a cooler region.

In fire-prone areas, keep dry organic mulch away from buildings, ignition sources and machinery, and follow local fire-safety guidance.

Provide Temporary Shade

Some crops benefit from protection from intense afternoon sun during exceptional heat.

Shade cloth, lightweight screens or temporary covers can reduce leaf and fruit temperatures. Position them so that air can circulate and rain or irrigation can still reach the soil.

Do not make the area completely dark. Plants still require light for growth, and dense coverings can trap heat if ventilation is poor.

Shade is particularly useful for seedlings, recent transplants and crops that prefer cooler conditions. It may also reduce sunscald on exposed fruit.

Use Other Plants for Shade Carefully

Taller crops can provide partial shade to lower-growing plants, while established trees or structures may shelter beds from the strongest afternoon sun.

This can be helpful in hot climates, but surrounding plants also compete for water. Avoid planting so densely that roots, light and airflow become severely restricted.

In cooler regions, excessive shade may reduce growth and keep foliage damp. Adapt the arrangement to the normal conditions in your garden.

Reduce the Effect of Wind

Hot, dry wind can increase water loss dramatically.

Permeable windbreaks such as hedges, mesh or spaced fencing slow the wind without stopping it completely. Solid barriers can create strong turbulence on the sheltered side.

Temporary screens can protect young plants while they establish. Make sure they are securely fixed and do not cast unwanted shade across the growing area.

Look After Containers

Containers can become dangerously hot and dry because their roots cannot escape into cooler surrounding soil.

Move suitable pots away from reflective walls and intense afternoon sun. Grouping containers can reduce exposure to drying wind and shade the sides of neighbouring pots.

Check moisture below the surface and water thoroughly. If compost has shrunk from the sides, apply water in stages so that the root ball is re-wetted rather than allowing the water to run straight through.

Small or root-filled pots dry particularly quickly. Where practical, move plants into larger containers before periods of extreme summer heat rather than during the heatwave itself.

Manage Greenhouses

Greenhouses can become much hotter than the outdoor air.

Open doors and vents as conditions require, and use suitable shading when necessary. Check containers and beds regularly because they receive no natural rainfall.

Water the soil rather than routinely soaking the foliage. Good ventilation is important, especially if evening watering increases humidity overnight.

Automatic irrigation can help, but check every outlet and adjust its duration as the weather and plant size change.

Avoid Adding Extra Stress

During extreme heat, postpone unnecessary transplanting, heavy pruning and root disturbance.

Do not apply concentrated fertiliser to dry soil. Fertilising will not correct water stress and may cause further root damage. Restore appropriate moisture first and wait until the plant is recovering.

Harvest vegetables promptly where this reduces the burden on stressed plants. Remove badly damaged material only where necessary, because remaining foliage may still shade fruit and soil.

Grow With Drought in Mind

Long-term resilience begins with crop and variety selection.

Choose plants suited to your normal growing season, rainfall and temperature range. Locally successful varieties are often more dependable than those selected for a very different climate.

Sow and plant according to local conditions rather than fixed calendar dates. In regions with very hot summers, some crops may perform better when grown during spring or autumn. Elsewhere, the warm season may be short and every suitable week valuable.

Healthy soil, mature compost, ground cover and minimal unnecessary disturbance all improve the garden’s ability to manage limited water.

Plan Your Water Supply

Collect rainwater where it is safe and practical, and increase storage gradually if local rainfall patterns make this worthwhile.

Inspect hoses, connectors and irrigation systems for leaks. Direct water only towards productive areas and repair dripping taps promptly.

Follow any local restrictions affecting mains water, wells, boreholes or surface water. During prolonged drought, household supply, drinking water and official conservation requirements take priority over maintaining every garden crop.

Recovering After Heat or Drought

When cooler weather or rain returns, do not assume that one shower has fully rehydrated the soil. Check how deeply the moisture has travelled.

Resume normal watering gradually according to soil conditions. Remove plants that have died, but allow stressed plants time to recover before making final decisions.

Review which beds dried first, which crops coped well and where shade or wind protection was most effective. These observations will help you prepare for future extreme weather.

A resilient garden is not one that remains unaffected by heat or drought. It is one designed and managed to use available water carefully, protect its most vulnerable plants and recover when conditions improve.