Why Small Gardens Struggle in a Heatwave

Small outdoor spaces — courtyards, balconies, narrow back gardens — heat up faster than their larger cousins. Paving, brick walls and fence panels soak up the sun all day and then radiate it back at night, so your pots and beds never really cool down. Add a dry spell and a hosepipe ban into the mix and even tough plants start to look sorry for themselves. The good news is that a few hours of preparation in late spring will carry your garden through the worst of July and August. None of it is expensive, and most of it takes an afternoon.

Mulch: The Cheapest Shade You Can Buy

If you do only one thing, do this. A layer of mulch over bare soil slows evaporation dramatically, keeps roots cooler and helps suppress weeds that would otherwise compete for every drop of water. Spread a 5–7cm layer of well-rotted garden compost, bark chippings or leafmould over damp soil — mulch over dry ground simply locks the dryness in, so water first if you need to. Keep it clear of stems and crowns by a few centimetres to avoid rotting them off.

In small beds you can be generous with gravel or horticultural grit around Mediterranean herbs such as rosemary, thyme and lavender, which prefer sharp drainage anyway.

• Top up mulch mid-summer; it thins out as worms pull it down into the soil.
• Mulch containers too — a centimetre of grit or gravel on the surface of a pot cuts water loss noticeably.
• Don't mulch dry, dusty soil and expect a miracle. Soak it first, then cover.

Install a Water Butt Before You Need It

A water butt is the single best investment for a small garden. Even a modest 100–200 litre butt filled by a downpipe from a shed or house roof will keep a balcony or courtyard going for weeks. Fit it now, while rain is still likely, and check that the diverter is set correctly so it actually catches the runoff.

If space is tight, look at slimline or wall-mounted butts, or link two smaller ones together with a connector kit. Keep the lid on — standing water is a magnet for mosquitoes — and site it where gravity helps you: raised on a sturdy stand so a watering can fits underneath, or high enough to feed a soaker hose.

• Use a watering can rather than a hose. It forces you to water properly and uses far less.
• Add a tap and a short length of hose to reach the back of the border.
• Empty and clean the butt in autumn so it doesn't stagnate over winter.

Move Containers Into Partial Shade

Containers are the first casualties of a heatwave. A terracotta pot in full sun can dry out in a single afternoon, and roots pressed against hot walls get cooked. Before the really hot weather arrives, move pots to a spot that gets morning sun and afternoon shade — east or north-east facing is ideal.

Group pots together so their foliage shades the compost surface and the cluster creates its own humid microclimate. Stand them on saucers, gravel trays or a shallow tray of water-retaining granules. Raise pots onto feet so water drains freely instead of sitting under the base.

• Double-pot: slip a smaller pot inside a larger one with damp newspaper or compost between the two for insulation.
• Move salads, leafy greens and young seedlings first — they bolt or wilt fastest.
• Shade greenhouses and cold frames with a wash or netting; a few degrees makes a real difference.

Watering That Actually Works

Little and often is the worst thing you can do. It encourages shallow roots that fail the moment a heatwave hits. Water thoroughly, then leave it. Aim for a good soak two or three times a week rather than a daily sprinkle, and check by pushing a finger into the compost — if it's damp 5cm down, you can wait.

Water in the early morning or late evening, when less is lost to evaporation. Direct the flow at the soil, not the leaves: wet foliage in strong sun can scorch, and damp leaves overnight invite mildew. Newly planted shrubs and trees need the most attention in their first two summers; after that they should manage largely on their own.

Planning Ahead for the Rest of Summer

Choose plants that shrug off dry spells: lavender, sedum, rosemary, oregano, hardy geraniums, ornamental grasses and silver-leaved plants such as Stachys byzantina. They look good in small spaces and need far less coddling than thirsty bedding.

Don't sow or plant into parched ground in July — you'll spend the rest of the summer fighting a losing battle. Wait for rain, or start seeds in modules in the shade and plant them out once the soil is workable again. Keep a little patch of shade for yourself too, with a chair and a jug of something cold. A garden you actually enjoy sitting in is the whole point.