Prepare the harvest for autumn
The final week of August is about storing what is ready, protecting what is still growing and making a calm transition into September.
Photo: Amie Roussel via Unsplash
The last week of August often feels like a meeting point between two seasons.
Summer crops are still filling baskets, but growth is beginning to slow. The evenings are drawing in, dew sits on the leaves for longer and empty spaces are appearing where earlier crops have finished.
This week’s jobs are about deciding what should be eaten now, what can be stored and what needs a little more time. It is also a good moment to prepare protected spaces for autumn and winter growing.
What to sow indoors or under cover
Hardy winter lettuce
Sow a small number in modules. Choose a variety described as suitable for winter growing rather than an ordinary summer lettuce.
Overwintering onions
Make a final module sowing of overwintering onion seed. Keep the tray in an unheated greenhouse or sheltered cold frame.
Parsley
Sow in pots that can remain under cover. Germination may be slow, so keep the compost moist and be patient.
Pea shoots
Sow closely in a shallow container for a quick windowsill crop rather than growing the plants for peas.
As daylight decreases, seedlings will grow more slowly. Avoid sowing large quantities that will compete for limited protected space.
What to sow or plant outside
- Corn salad: sow in a short row or container for hardy leaves during cooler weather.
- Winter spinach: sow in a sheltered position and protect young plants from slugs.
- Rocket: cooler conditions can produce softer, less intensely peppery leaves.
- Mizuna: sow thinly in a bed, window box or large container for autumn picking.
- Spring onions: sow a hardy variety to overwinter for an early crop next year.
- Spring cabbage: plant out established young plants and protect them with fine netting.
Clear only the space you need. Undisturbed soil covered by growing plants is better protected from heavy autumn rain than completely bare ground.
🥔 Check potatoes before lifting them
Some second-early and early maincrop potatoes may be ready, but later maincrops can remain in the ground while their foliage is still healthy.
Test one plant first
- Choose one plant from the end of a row.
- Carefully lift it with a garden fork.
- Check the size and number of tubers.
- Rub the skin gently with your thumb.
If the skin rubs away very easily, the potatoes are not yet ideal for long storage. Leave the remaining plants for longer if conditions are suitable.
Preparing potatoes for storage
Lift potatoes during dry weather and leave them on the soil surface only long enough for excess moisture to dry. Move them out of sunlight promptly because light can make potatoes turn green.
Store only undamaged potatoes. Use any cut, bruised or pierced tubers first rather than placing them into long-term storage.
What may be ready to harvest
- Damsons and plums: pick ripe fruit before it falls or splits after heavy rain.
- Early apples: lift and twist gently. Store only sound fruit without bruises or insect damage.
- Sweetcorn: eat as soon as possible after picking for the best flavour.
- Beetroot: lift medium-sized roots for roasting, pickling or freezing.
- Carrots: harvest as needed and protect remaining roots from carrot fly.
- Potatoes: test a plant before deciding whether to lift the entire row.
- Tomatoes: collect ripe and nearly ripe fruit regularly, particularly before wet weather.
- Autumn raspberries: pick gently as soon as the berries are fully coloured.
- Beans: gather remaining tender pods and leave selected healthy pods to mature only if you are saving seed.
Store apples carefully
Not every apple is suitable for storage. Early varieties are often best eaten soon after picking, while later varieties may keep for several weeks or months.
- Choose firm, unblemished fruit.
- Do not store bruised, split or insect-damaged apples.
- Place them in a single layer so the fruits don’t touch.
- Keep them somewhere cool, dark and frost-free.
- Check regularly and remove anything beginning to rot.
Damaged apples can still be peeled and cooked immediately. Turn them into apple sauce, crumble filling or stewed fruit rather than wasting them.
Take late-summer herb cuttings
Healthy non-flowering shoots from rosemary, sage and thyme can be used to make new plants.
- Cut a healthy shoot approximately 8–10cm long.
- Remove the leaves from the lower half.
- Place the cutting around the edge of a pot of damp compost.
- Keep it somewhere bright but out of strong direct sunlight.
- Keep the compost lightly moist while roots develop.
Not every cutting will root, so place several around the same pot. They can be separated once they are growing strongly.
Jobs around the garden or allotment
- Remove greenhouse shading gradually as the days become shorter.
- Clean an empty section of the greenhouse ready for autumn pots and winter salads.
- Check leeks for damage caused by leek moth or allium leaf miner.
- Remove badly damaged brassica leaves but leave healthy foliage in place.
- Secure tall Brussels sprouts, kale and purple sprouting broccoli before autumn winds arrive.
- Cut finished climbing bean plants at ground level, leaving their roots to break down in the soil.
- Empty unproductive summer containers and refresh the compost before planting autumn leaves.
- Clear blocked greenhouse gutters and water-butt connections.
- Wash and dry storage boxes, trays and paper sacks before the main autumn harvest begins.
Go on a potato treasure hunt
If a potato plant is ready to lift, let children search through the loosened soil for hidden tubers.
Count the potatoes, arrange them from smallest to largest or weigh the finished harvest. Check the soil yourself afterwards because smaller potatoes are easy to miss.
Children should wear gloves, wash their hands afterwards and be reminded that green potatoes must not be eaten.
This week’s quick checklist
- Sow one container of hardy winter leaves
- Plant out spring cabbage
- Test one potato plant before lifting the row
- Sort sound apples from damaged fruit
- Take rosemary, sage or thyme cuttings
- Secure tall winter brassicas
- Prepare a greenhouse space for autumn
- Check leeks for pest damage
- Clean storage trays and boxes
- Have a potato hunt with children