What to Plant in September: UK Sowing Guide
September's split between two jobs — squeezing in the last quick crops and starting the bulbs that flower next spring.
September is a hinge month — the last realistic window for a few quick crops, and the start of bulb-planting season for a spring display you'll thank yourself for in March.
Vegetables to sow now
Only the fastest crops still have time to mature before growth slows for winter:
| Crop | Sow | Typical harvest |
|---|---|---|
| Spring cabbage | Now, direct or modules | March–May |
| Winter lettuce & land cress | Now, under cover | 6–8 weeks |
| Japanese onion sets | Mid–late September | Following June |
| Overwintering broad beans (e.g. Aquadulce) | Late September–October | Following May–June |
Everything else — beans, courgettes, most salads — is done for the year. Sowing them now wastes seed; the light and warmth simply aren't there to finish the job.
Bulbs to plant
Trumpet daffodil, Narcissus 'Aunt Betty'
September is early for most spring bulbs, but not for all of them:
- Daffodils (narcissus): plant now through November — early is better, since they establish roots before winter and flower stronger for it.
- Crocus, snowdrops (in the green) and alliums: plant from September onwards.
- Tulips: hold off until November. Planting tulips this early raises the risk of tulip fire, a fungal disease that thrives in warm soil.
Other jobs for September
- Take semi-ripe cuttings of shrubs like lavender, rosemary and hydrangea while the wood is firm but not yet woody.
- Start a compost bay with the first flush of autumn leaves and spent summer bedding.
- Lift and divide overcrowded perennials — the soil is still warm enough for roots to settle before winter.
- Net ponds before leaves start falling in earnest, so you're not fishing them out all autumn.
Quick reference
- Sow: spring cabbage, winter lettuce, Japanese onion sets, overwintering broad beans
- Plant: daffodils, crocus, snowdrops, alliums — not tulips yet
- Hold off: tulips (wait for November), anything summer-sown
Compare bulbs and autumn essentials across UK retailers on GrowMuir, and see our guide to daffodil bulbs for planting depth and spacing.