September is one of the busiest harvest months in the UK garden. Summer crops such as tomatoes, beans, courgettes and cucumbers may still be producing, while potatoes, onions, apples, pears and other storage crops begin to take centre stage. Some pumpkins, winter squash, leeks and root vegetables may also be ready, although others will benefit from staying in the ground for longer. The key is to judge each crop by its condition rather than the calendar. This guide explains what may be ready in September, how to check and which crops are better left to mature.
What Can You Harvest in September in the UK?
Harvest timing depends on the variety, sowing or planting date, local weather, garden position and whether crops are grown outdoors or under cover. A sheltered southern garden may continue producing tender crops for weeks after an exposed northern plot has slowed down.
| Crop group | What may be ready in September |
|---|---|
| Vegetables | Tomatoes, courgettes, marrows, cucumbers, runner beans, French beans, peppers, chillies, aubergines, sweetcorn, maincrop potatoes, onions, shallots, late garlic, carrots, beetroot, turnips, celery, early leeks, salad leaves and summer brassicas |
| Fruit | Apples, pears, plums, gages, damsons, blackberries, autumn raspberries, figs, grapes and some late strawberries or blueberries |
| Herbs | Basil, mint, parsley, coriander, dill, chives, oregano, marjoram, thyme, rosemary, sage and lemon balm |
| May need longer | Some pumpkins and winter squash, parsnips, celeriac, swedes, winter leeks, Brussels sprouts, winter brassicas, late apples, pears and quince |
Use the table as a starting point, then check each crop for its own signs of readiness.
Vegetables to Harvest in September UK
Tender summer crops still need regular picking while conditions remain mild. Potatoes, alliums and some squash now need to be judged for storage as well as eating. Do not clear productive plants simply because September has arrived.
Courgettes and Marrows
- Ready when: Courgettes are young, firm and around their intended size. Marrows can be left to grow larger, with their skin becoming firmer as they mature.
- Watch for: Powdery mildew, soft patches, slug damage and fruits hidden beneath large leaves.
- September tip: Continue picking courgettes regularly to encourage further production. Bring the final fruits indoors before cold or frosty weather, especially if they are intended for storage.
Harvest Guide: How to Harvest Courgettes and Marrows
Cucumbers
- Ready when: Fruits are firm, evenly coloured and have reached a useful size for the variety.
- Watch for: Yellowing, bitterness, soft ends and rot during cool, damp weather.
- September tip: Greenhouse cucumbers usually continue cropping longer than outdoor plants. Keep ventilation open during mild days to reduce condensation and fungal problems.
Harvest Guide: When to Harvest Cucumbers
Tomatoes
- Ready when: Fruits have developed their expected colour and come away readily with a gentle twist.
- Watch for: Blight, splitting, grey mould and increasingly slow outdoor ripening.
- September tip: Leave healthy fruit to ripen on the plant while conditions remain suitable. If frost or serious blight threatens, harvest mature green tomatoes and ripen them indoors.
Harvest Guide: How to Harvest Tomatoes
Runner Beans
- Ready when: Pods are young, tender and still relatively slim, before the beans inside become noticeably swollen.
- Watch for: Tough, stringy pods and declining production when mature pods remain on the plant.
- September tip: Check plants every few days while they remain productive. Missed pods can quickly become large and fibrous, so pick them even if they are past their best for eating.
Harvest Guide: When to Pick Runner Beans
French Beans
- Ready when: Pods are slim, tender and snap cleanly when bent.
- Watch for: Swollen beans, leathery pods and cold-damaged plants.
- September tip: Pick usable pods regularly. If you want to save seed, leave selected pods on the plant until they become dry and papery.
Harvest Guide: How to Harvest French Beans
Peppers, Chillies and Aubergines
- Ready when: Peppers and chillies have reached a useful size or their intended colour. Aubergines should be firm, glossy and spring back slightly when pressed.
- Watch for: Dull or seedy aubergines, damaged fruit and very slow ripening outdoors.
- September tip: Protected crops may continue for several weeks, particularly in a greenhouse or polytunnel. Exposed outdoor plants are more dependent on the forecast, so harvest usable fruit before cold nights arrive.
Sweetcorn
- Ready when: The silks are brown and dry, and a pierced kernel releases a milky liquid.
- Watch for: Clear liquid, which means the cob needs longer, or thick paste, which suggests it is over-mature.
- September tip: Test individual cobs rather than harvesting the whole crop at once. Cook or eat sweetcorn soon after picking because its sugars begin converting to starch quickly.
Harvest Guide: How to Tell When Sweetcorn Is Ready
Maincrop Potatoes
- Ready when: The foliage has yellowed or died back and the tuber skins no longer rub away easily.
- Watch for: Blight, slug damage, green tubers and damage caused while lifting.
- September tip: Lift on a dry day where possible. Allow the potatoes to dry briefly, brush off loose soil and store only sound tubers in a cool, dark, frost-free place.
Harvest Guide: When to Harvest Maincrop Potatoes
Onions, Shallots and Late Garlic
- Ready when: Onion and shallot foliage has fallen naturally and begun to dry. Garlic is ready when several leaves have yellowed, although the exact timing depends on the type grown.
- Watch for: Thick green necks, bruising, rot and bulbs with damaged skins.
- September tip: Cure bulbs thoroughly in a dry, airy place before storing them. Do not store damaged or soft bulbs with healthy ones.
Harvest Guide: How to Harvest and Store Onions and Shallots
Root Vegetables: Carrots, Beetroot, Turnips and Radishes
- Ready when: Roots have reached a useful size but remain firm and tender.
- Watch for: Woody turnips, split roots, pest damage and oversized beetroot.
- September tip: Lift selectively. Smaller roots can usually remain in the soil and continue growing, while larger roots are best used before they become tough.
Early Leeks and Celery
- Ready when: Leeks have formed usable stems and celery plants have reached the desired size.
- Watch for: Leek rust, slug damage and tough or damaged celery stems.
- September tip: Harvest early leeks as required, but leave winter varieties to grow larger. Lift celery carefully so nearby plants are not disturbed.
Leafy Crops and Summer Brassicas
This group includes lettuce, spinach, chard, kale, cabbage, calabrese and cauliflower.
- Ready when: Leaves are healthy and usable, cabbage heads are firm, calabrese heads remain tight and cauliflower curds are compact.
- Watch for: Bolting, splitting, caterpillars, whitefly, slug damage and loose flowering heads.
- September tip: Harvest outer leaves from chard and kale so the centre can continue growing. Cut calabrese with a length of stem attached, as side shoots may follow.
Pumpkins and Winter Squash
- Ready when: The skin is hard, the colour is well developed, the fruit sounds hollow when tapped and the stem is becoming dry or corky.
- Watch for: Soft skin, damaged stalks, slug damage and approaching frost.
- September tip: Leave sound fruit on the plant for as long as conditions allow. Harvest before frost, cutting with a generous length of stem attached and handling the fruit carefully to avoid bruising.
Harvest Guide: When to Harvest Pumpkins and Winter Squash
Fruit to Harvest in September UK
September is a major month for apples, pears and autumn soft fruit. Harvest in stages because fruit on the same plant or tree may ripen at different times. Pick on a dry day and handle fruit carefully, particularly if it is intended for storage.
| Fruit | Ready when | What to watch for |
|---|---|---|
| Apples | Fully sized, properly coloured and easily removed with a gentle lift and twist | Premature windfalls, codling moth damage, wasps and bruising |
| Pears | Mature fruit lifts away when raised and twisted; finish ripening indoors | Waiting until pears become soft on the tree |
| Plums and gages | Fully coloured, slightly soft and easily detached | Wasps, splitting, brown rot and uneven ripening |
| Damsons | Deeply coloured and easy to remove; slightly firmer fruit can be used for preserving | Picking too early or allowing fruit to become overripe |
| Autumn raspberries | Richly coloured and easily pulled from the plug | Mould, squashed fruit and missed ripe berries |
| Blackberries | Completely black, plump and easily detached | Red sections, mould, birds and overripe fruit |
| Figs | Soft, hanging down and beginning to split slightly near the base | Firm upright fruit and wasp damage |
| Grapes | Fully coloured, sweet and properly flavoured when tasted | Uneven ripening, mildew and damaged bunches |
| Late strawberries or blueberries | Fully coloured and easily detached | Slugs, birds, mould and assuming all varieties crop this late |
Eat or preserve soft fruit promptly because it deteriorates quickly once picked. Store only unblemished apples and pears, and check stored fruit regularly. Remove anything beginning to rot before the problem spreads.
Apples
Apples are often ready in stages during September. A ripe apple should have developed the expected colour for its variety and should come away with a gentle lift and twist rather than needing to be pulled. Taste one before picking large quantities. Sound windfalls can be used promptly, but fruit that is bruised, split or damaged by pests is unsuitable for long-term storage.
Pears
Most pears should not be left until they become soft on the tree. Pick mature but firm fruit when it lifts away easily, then allow it to finish ripening indoors. The exact timing varies considerably between varieties, so test individual pears rather than harvesting the whole tree at once.
Plums, Gages and Damsons
Plums and gages are ready when they are fully coloured, slightly soft and easy to detach. Damsons are often firmer and more acidic when picked, making them suitable for cooking and preserving. Pick fruit promptly during warm weather because wasps and brown rot can quickly damage a crop.
Autumn Raspberries and Blackberries
Pick autumn raspberries and blackberries when they are fully coloured and come away easily. If berries resist picking, they usually need longer. Check plants frequently, remove mouldy fruit and protect the crop from birds where necessary.
Figs and Grapes
Figs are ready when they soften, hang down and may begin to split slightly near the base. Grapes should be fully coloured, sweet and properly flavoured when tasted. Bunches do not always ripen evenly, so remove damaged grapes and harvest the best clusters first.
Herbs to Harvest in September UK
September is a useful time to take final substantial harvests from tender herbs and preserve surplus growth. Avoid stripping hardy perennial herbs completely, as they still need enough foliage to remain healthy through autumn and winter.
| Herb | What to harvest | What to watch for |
|---|---|---|
| Basil | Healthy shoot tips and leaves | Cooler nights, yellowing and blackened leaves |
| Mint and lemon balm | Young leafy shoots | Coarse, damaged or rust-affected growth |
| Parsley | Outer stems cut near the base | Yellowing leaves and slug damage |
| Coriander and dill | Young leaves or mature seed heads | Damp seed heads and coarse flowering growth |
| Chives | Fresh leaves cut close to the base | Rust and tough older leaves |
| Oregano and marjoram | Healthy leafy shoots | Woody or spent flowering growth |
| Thyme | Young non-woody shoots | Cutting too deeply into old wood |
| Rosemary and sage | Young healthy shoots | Overharvesting and damaged leaves |
Dry woody herbs such as rosemary, sage, thyme, oregano and marjoram in small bunches or on trays in a warm, dry, well-ventilated place. Freeze softer herbs such as basil, parsley, chives and coriander where drying would weaken their flavour. Collect herb seeds only when the seed heads are fully dry, then store them in labelled paper packets.
Crops That May Not Be Ready in September
September is not a deadline for clearing the plot. Many autumn and winter crops are usable now but will continue improving if left in suitable conditions.
| Crop | Why it may need longer | What to do in September |
|---|---|---|
| Pumpkins and winter squash | Skin, colour and stem may not yet be mature enough for storage | Leave them growing unless frost, disease or damage threatens |
| Late maincrop potatoes | Foliage may still be green and tuber skins may not have set | Leave healthy plants to finish or test one plant before lifting |
| Parsnips | Roots continue swelling and often become sweeter after frost | Leave in the ground unless needed |
| Celeriac | Normally begins cropping from October | Keep watered during dry weather and allow roots to develop |
| Swedes | Usable from early autumn but can remain in the soil | Lift only what is required |
| Winter leeks | Stems may still be increasing in size | Harvest early varieties and leave winter types |
| Brussels sprouts | Buttons may still be loose or undersized | Support plants and remove yellowing lower leaves |
| Winter brassicas | Heads, shoots or leaves are still developing | Protect from caterpillars, pigeons and whitefly |
| Late apples, pears and quince | The variety may have a later natural picking window | Test individual fruits rather than stripping the tree |
| Outdoor tomatoes, peppers and chillies | Healthy fruit may continue ripening during a mild September | Monitor the forecast and harvest before frost or serious disease |
Parsnips are often better left in the ground because colder weather improves their sweetness. Swedes, winter leeks and some brassicas can also remain in place, provided they are protected from pests and severe weather. If you are unsure about a crop, lift or pick one specimen and assess its size, texture and flavour before harvesting the rest.
How Weather and Location Affect September Harvests
Southern, sheltered and urban gardens may continue harvesting tender crops well into September, while northern, exposed and higher-altitude plots usually cool sooner. A greenhouse or polytunnel can extend the season for tomatoes, cucumbers, peppers, chillies and aubergines, although shorter days and cooler nights will still slow growth and ripening.
Damp conditions increase the risk of blight, mould and fruit rot, particularly where foliage remains wet overnight. Use crop condition and the local forecast rather than treating the month as a fixed deadline. A mild, dry September may allow crops to remain outside for longer, while an early frost or prolonged wet spell can bring the harvest forward.
September Harvest Tips for UK Gardeners
- Keep picking productive crops: Beans, courgettes, cucumbers, tomatoes and autumn raspberries still benefit from regular harvesting.
- Watch the frost forecast: Prioritise tender outdoor crops when colder nights are expected.
- Harvest storage crops in dry weather: Potatoes, onions, squash, apples and pears store better when gathered dry.
- Store only sound produce: Use bruised, split or pest-damaged crops first.
- Do not wash potatoes or storage roots: Brush away loose soil and allow them to dry before storage.
- Cure onions and squash properly: Dry skins and good airflow reduce storage losses.
- Handle orchard fruit gently: Bruised apples and pears deteriorate quickly.
- Leave hardy crops where practical: Parsnips, swedes, winter leeks and several brassicas can remain in the ground.
- Manage greenhouse humidity: Reduce watering as growth slows and maintain ventilation during mild weather.
- Remove diseased produce promptly: Do not allow blight, mould or brown rot to spread through healthy crops or stored harvests.
Managing a September Glut
September gluts increasingly include crops suitable for winter storage as well as produce that needs immediate cooking or preserving. Deal with the most perishable crops first, then prepare sound storage crops carefully.
| Surplus crop | Ways to use or preserve it |
|---|---|
| Runner and French beans | Blanch and freeze, make chutney or leave selected pods for seed |
| Tomatoes, peppers and chillies | Cook into sauces, soups, chutneys or chilli pastes |
| Courgettes and marrows | Add to soups and sauces, make chutney or freeze cooked dishes |
| Apples and pears | Store suitable varieties, cook into compotes, freeze or juice |
| Plums, damsons and berries | Freeze, make jam, cook into compotes or use in puddings |
| Maincrop potatoes | Dry and store in paper sacks somewhere cool and dark |
| Onions, shallots and garlic | Cure thoroughly before storing in nets or trays |
| Pumpkins and winter squash | Cure and store whole if undamaged |
| Herbs | Dry woody herbs and freeze softer leaves |
Check stored crops regularly and remove anything soft, mouldy or beginning to rot.
What to Sow After a September Harvest
Cleared beds can still be used for winter lettuce, spinach, rocket, salad leaves and radishes. Overwintering onion sets and spring cabbage can also be planted where appropriate. If another food crop is unlikely to establish, sow a suitable green manure to protect the soil and reduce weed growth.
Clear weeds and unhealthy crop remains before reusing the bed, and avoid leaving productive soil bare over winter.
For crop-by-crop timings and advice on sowing outdoors or under cover, see our complete guide to what to sow in September in the UK.
FAQ – What to Harvest in September UK
Common September vegetables include tomatoes, courgettes, marrows, cucumbers, runner beans, French beans, peppers, chillies, aubergines, sweetcorn, maincrop potatoes, onions, shallots, garlic, carrots, beetroot, turnips, celery, early leeks, salad leaves and summer brassicas. Readiness depends on the variety, sowing date, weather and growing conditions.
Apples, pears, plums, gages, damsons, blackberries, autumn raspberries, figs and grapes are among the main September fruits. Some late strawberries and blueberries may also crop, particularly in sheltered gardens or where later varieties are grown.
They may be. Check whether the foliage has yellowed or died back and whether the skins remain firmly attached when rubbed. If the foliage is still healthy and green, the crop may benefit from more time. The harvest window can extend into October, depending on the variety and weather.
Harvest ripe fruit in September if the skin is hard, the colour is developed and the stem is drying or becoming corky. Healthy immature fruit can remain on the plant while conditions are mild, but harvest before frost or if disease and damage threaten.
A ripe apple should be fully sized, properly coloured and easy to remove with a gentle lift and twist. Taste one to check its flavour. Sound windfalls can indicate that the crop is approaching readiness, but bruised or damaged fruit should be used promptly rather than stored.
Usually not. Most pears should be picked when mature but still firm, then allowed to ripen indoors. If left until soft on the tree, they may develop a poor texture or begin to rot from the inside.
Yes, but you do not usually need to lift the whole crop. Parsnips can remain in the ground and often become sweeter after exposure to colder weather. Lift only what you need, provided the soil is not waterlogged or frozen.
Prioritise tomatoes, peppers, chillies, aubergines, cucumbers, courgettes, beans, pumpkins and winter squash. Bring in any tender herbs and harvest usable fruit from outdoor plants if frost is forecast.
Shorter days, cooler nights, the variety, a shaded position or late planting can all slow ripening. Leave healthy fruit on the plant while the weather remains mild. If frost or serious blight is forecast, pick mature green tomatoes and ripen them indoors in a warm, bright place away from direct sunlight.
You can sow winter salads, spinach, rocket and radishes, or plant overwintering onion sets and spring cabbage where conditions are suitable. Green manure is another option for beds that will not be used again until spring.
Cure onions, shallots, garlic and winter squash in a dry, airy place before storing. Keep potatoes cool, dark and dry in paper or breathable sacks. Store apples and pears separately, handle them gently and check them regularly. Only store undamaged fruit and vegetables, using bruised or split produce first.
Final Thoughts: September Bridges Summer and Autumn
September combines continued picking with the beginning of the main storage harvest. Keep productive summer crops going while conditions allow, particularly beans, courgettes, tomatoes, cucumbers and autumn raspberries. At the same time, lift potatoes and alliums when they are properly mature, and harvest apples and pears in stages as they reach readiness.
Do not rush crops that benefit from remaining in the ground. Parsnips, swedes, winter leeks, Brussels sprouts and some winter brassicas can continue developing into autumn, while pumpkins and winter squash may need more time to form a hard skin. The most reliable approach is to judge each crop by its readiness, condition and the local forecast rather than by the date alone.
