What to Plant in September (UK)

September is the great handover: the summer crops are still pouring in while you quietly set up next year. The light is softening, the first cool nights arrive, and there's plenty to harvest, a little to sow, and some valuable overwintering jobs to crack on with.

This is a quick monthly checklist. For the year-round picture, see the month-by-month gardening guide, and to check exact timings for your area, use the planting calendar.

Sow indoors

A short list this month — most sowing is heading outdoors or under cover now.

• Winter salad leaves — sow in modules to plant out under cover, for winter salad leaves to crop through the cold months.
• Hardy herbs like parsley and coriander on a windowsill for a fresh supply into autumn.

Sow outdoors

The soil is still warm, so quick crops and overwintering sowings establish fast.

• Winter salad and hardy lettuce — sow now for cut-and-come-again leaves under a cloche or cold frame.
• Spinach — a final sowing for overwintered pickings.
• Radishes — a last fast crop before the cold; ready in 4–6 weeks.
• Hardy peas and broad beans (end of month) — an autumn sowing for an early spring crop. See sowing broad beans in autumn.
• Green manures — sow field beans, grazing rye or phacelia on any bare bed to protect and feed the soil over winter. A great companion to a no-dig approach.

Plant out

September is prime planting month for crops that sit through winter.

• Overwintering onion sets — plant now for an earlier crop next summer.
• Garlic (from the end of the month) — it actually needs a cold spell to bulb up well.
• Spring cabbage — plant out young plants for tender spring greens.
• New strawberry runners — pot up or plant rooted runners now so they settle in before winter and crop well next June.

Harvest now

The pantry-filling month. Pick regularly to keep plants productive and to beat the first frosts.

• Maincrop potatoes — lift on a dry day, let them dry, then store in paper or hessian sacks somewhere cool and dark.
• Squash and pumpkins — leave to ripen and "cure" in the sun; harvest before the first frost.
• Sweetcorn — pick when the tassels brown and a squeezed kernel runs milky.
• Apples and autumn raspberries — pick apples when they twist off easily; raspberries every few days.
• Tomatoes — keep picking; bring any green ones indoors to ripen as nights cool.
• Courgettes, beans and beetroot — still cropping; harvest often before they go over.

Jobs for September

• Start clearing spent crops — pull out finished beans, courgettes and tomatoes once they stop producing.
• Compost the lot — add spent plants (minus anything diseased) to the heap. New to it? See how to make compost.
• Net brassicas to protect spring cabbage from pigeons.
• Order garlic and onion sets if you haven't already, and browse seed catalogues for next year.
• Reduce watering and feeding of greenhouse crops as growth slows.

Not sure where to begin? The easiest crops for beginners are a gentle starting point, and our guide to starting a vegetable garden covers the basics.

Whatever you get done this month, every job nudges you towards next year's harvest. Pick a couple from the list, and check the planting calendar for what's coming in October.