What to Do on Your Allotment in August

August is the month of abundance and mild chaos. More produce than you can possibly eat arrives simultaneously — and the smart allotment holder is already thinking about winter. The window for sowing winter crops is short; act now.

What to sow in August

This is your last chance for several key crops: - Winter salads — lamb's lettuce, land cress, winter purslane, hardy lettuce varieties. Sow in rows or scatter in vacant patches. - Spring onions — a late sowing will overwinter and be ready in spring. - Spinach — August is ideal for an autumn/winter cropping spinach. Sow direct. - Turnips — a fast-growing root that tolerates autumn conditions well. - Chinese cabbage and pak choi — bolt-resistant when sown in August. Ready in 6–8 weeks. - Fennel — last chance; earlier sowings will have bolted.

What to harvest in August

The list is long: - Tomatoes — the main crop. Harvest as they ripen; don't let them split on the vine. - Courgettes, cucumbers, and peppers — daily if you can. - Sweetcorn — test ripeness by pressing a kernel with a fingernail. Milky white juice means it is ready. Clear juice means not yet. Dry means too late. - Runner and french beans — still very productive. - Aubergines — harvest while skin is still glossy. - Onions and garlic — if foliage is down, they are ready. Dry thoroughly before storing. - Raspberries and blackberries — peak production. - Squash and pumpkins — leave on the plant until the stalk begins to dry. Skin should resist a thumbnail.

Key jobs for August

Dry and store the allium harvest. Onions, shallots, and garlic need thorough drying. Lay on slatted trays or tie in bunches in a warm, airy space — a greenhouse or shed with good airflow. Properly dried bulbs store for 6–9 months.

Prune summer raspberries after harvest. Cut canes that have just fruited to ground level. Tie in the new green canes that have grown this year — these will fruit next summer.

Net brassicas now. Pigeons are particularly active in August. The cabbage white butterfly second brood hatches; check brassica leaves for eggs and caterpillars.

Pests to watch

• Late blight on tomatoes and potatoes — more common in warm, wet August weather. Monitor daily.
• Carrot fly second generation — the second wave arrives in August. Keep carrots under fine mesh.
• White rot on onions — white fluffy mould at the base of bulbs. Remove and destroy affected plants; do not compost. The fungus persists in soil for 20+ years.

Quick win: check sweetcorn readiness before cutting

Test every cob before cutting: gently pull back a section of husk and press a kernel. Milky juice = perfect. Clear juice = wait a few days. If dry = overripe. Once cut, sweetness declines rapidly — cook within hours for best flavour.