UK growing guide · Autumn
What can I plant in September?
Last updated
September is a change of gear. Vegetables to plant in September in the UK are the overwintering ones: autumn onion sets, spring cabbage, winter salads, and in mild areas a first sowing of broad beans.
It is also storage month. Potatoes, apples and squash picked carefully now are what you eat in November. Bruises and damp are what you throw away.
What to sow in September
Vegetables to plant in September in the UK, split between sowing under cover and sowing outside.
Indoors or under cover
A cold frame or greenhouse is useful for winter lettuce and spinach if outdoor nights are already cool. They don't need heat, just protection.
Lettuce — winter varieties, under cover
Spinach — in modules- Broad beans — in pots, if your garden is cold or wet
Outdoors
Sow while the soil is still warm. Germination is quicker now than it will be in October, and the plants establish before the short days.
- Spinach — for winter picking
- Lettuce — hardy winter kinds
Radishes — a quick last row- Spring onions
- Broad beans — late in the month, mild and well-drained plots
What to plant out in September
Plant onion sets and spring cabbage into ground cleared of summer crops. Don't plant them into a bed that grew onions last year.
Autumn onion sets — overwintering types- Cabbage — spring cabbage, firmed in well
- Lettuce — winter varieties, under a cloche if you have one
- Spinach
What to harvest in September
Lift maincrop potatoes on a dry day. Pick squash and pumpkins once the skins are hard and the stalk has dried, and get them in before a hard frost.
Potatoes — maincrops, stored dark and dry
Tomatoes — ripen green ones indoors as nights cool
Courgettes — they're slowing- French beans
Sweetcorn
Pumpkins — hard skin, dry stalk, before a hard frost
Beetroot
Carrots- Apples and pears
September jobs on the plot
Clear, store and cover. A tidy September plot is easier to plant in October.
Lift maincrop potatoes
Leave them to dry for a few hours, then store unwashed in paper sacks, in the dark. Light turns them green.
Clear spent crops
Bean stalks can be cut at the base so the roots stay in the soil. Diseased tomato and potato growth goes in the bin, not the compost.
Net winter brassicas
Pigeons get hungrier as other food fades. Net kale, cabbage and sprouts before the damage, not after.
Start a leaf-mould cage
Autumn leaves piled in a wire bay become leaf mould. It is the best thing I know for seedbeds, and it costs nothing.
Frost and where you garden
North and south in September
The first light frosts are possible late in September in northern England, Scotland and on high ground. Tender crops — tomatoes, courgettes, pumpkins — need picking or covering if a frost is forecast. The south is usually still mild, but it is worth having fleece to hand.
Further north, and high ground
In northern England and Scotland, don't delay lifting potatoes and squash. A September frost is much more likely than it is further south. Get spring cabbage and onion sets in while the soil still has some warmth.
The south and sheltered coasts
Mild southern and western gardens can sow overwintering broad beans outside towards the end of the month, in free-draining soil. Winter salads sown now establish well. Heavy clay can wait for a drier week.
Easy mistakes in September
September losses are usually in the shed, not the bed: damp stores and uncovered brassicas.
Washing potatoes before storage
Damp skins rot. Brush off the soil once they are dry and leave them unwashed.
Leaving pumpkins out for the first hard frost
A light frost may not finish them. A hard one will. Get them into a shed.
Planting onions after onions
Give the onion family a different bed from last year, and from garlic and shallots.
Keep September on the dashboard
Sproutly is a web garden diary for UK fruit and veg growers. Add the plants and the jobs, then see what's due on your dashboard.
Record your sowings
Note what you sowed in September, and which bed it went in.
Plan the month's jobs
Add planting, covering and picking as tasks with a due date.
See what's due
Your dashboard shows what's due and what's overdue. Sproutly does not email you or send a push to your phone.
Sketch the beds
Use the garden planner to try a layout before you plant it for real.
Ready to plan your September garden?
Add this month's plants and jobs to your diary. Basic is free for up to 3 plants and 3 tasks. Pro is £5 a month if you want more, including recurring tasks.
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Gardening advice is provided as a general guide based on typical UK conditions. Weather soil and local climate can vary so always use your judgement and adjust timing as needed for your own garden.