September in the Garden
The season of gathering and planting for tomorrow 🍎
September signals the turning point between summer and autumn. The air feels cooler, the evenings arrive sooner, and the garden begins to slow — yet it’s still full of life and harvest. It’s a month for reaping rewards, tidying up, and planning ahead for next spring’s colour. While many plants wind down, there’s still plenty to sow, harvest, and enjoy in the late-season sunshine.
Top Jobs for September
- Sow for next season – As the soil cools, planting slows, but there’s still time to sow winter and spring cabbages, winter spinach, and White Lisbon spring onions for harvesting early next year.
- Harvest summer fruiting vegetables – Pick the last of your broad beans, peas, tomatoes, chillies, and peppers while they’re still in good condition.
- Enjoy your harvest – Gather carrots, beetroot, broccoli, and early Brussels sprouts as they mature.
- Plant green manure – Once beds are cleared, sow comfrey, alfalfa, or grazing rye to cover bare soil and enrich it for next spring.
- Cure squashes – Lay squashes on straw or cardboard to keep them off damp soil, preventing rot. Once ripened, cure them in the sun to harden their skins before storing in a cool, dark place.
- Lift maincrop onions – When foliage dies back, pull onions and dry them in a well-ventilated space (but not in direct hot sun). Hang or spread them out to prevent rot.
- Harvest apples and pears – Check fruits for ripeness; they should detach easily when twisted. Store apples in a cool, frost-free place for up to two months; pears can be kept in the fridge for about a week.
- Prune berry bushes – Cut down fruiting canes to the ground and tie in this year’s new growth to a support — these will fruit next summer.
- Harvest maincrop potatoes – Gently dig a test clump; if they’re mature, lift the rest before slugs or frost damage them.
- Tidy greenhouses – Remove old leaves from tomatoes and clear out shading from windows to make the most of autumn light.
General Garden Care
September brings cooler winds and shorter days, but the soil still holds warmth. It’s an ideal time to divide perennials, collect seeds, and plant spring-flowering bulbs for next year’s display. Keep watering new plants during dry spells, but start reducing watering for houseplants as they slow their growth. Clean out cold frames and greenhouses, and get them ready for overwintering tender plants.
Top 10 Jobs This Month
- Divide herbaceous perennials.
- Pick autumn raspberries.
- Collect and sow seeds from perennials and hardy annuals.
- Dig up remaining potatoes before slug damage occurs.
- Net ponds before leaves start to fall.
- Keep watering new plants using rain or grey water.
- Reduce watering for houseplants.
- Clean and tidy greenhouses and cold frames for autumn.
- Cover leafy vegetable crops with bird-proof netting.
- Plant spring-flowering bulbs such as daffodils, crocus, and tulips.
What’s in Stock This Month 🌿
At Newquay Garden Centre, September is all about harvest and preparation for next spring. You’ll find:
- Spring-flowering bulbs — daffodils, tulips, crocus, and hyacinths
- Winter and spring vegetable plants — cabbages, onions, and spinach
- Green manure seed mixes to improve soil for next year
- Fertilisers, compost, and mulch to replenish tired summer soil
- Autumn perennials and ornamental grasses for late-season colour
- Garden netting, ties, and plant supports to prepare for autumn winds
Whether you’re harvesting the fruits of summer or planting for spring, our team is here to help you make the most of the changing season.
Cornwall Gardening Tip
Cornwall’s mild coastal climate means the growing season lasts longer, so you can keep harvesting and sowing well into September. However, autumn storms can arrive early — stake tall plants and secure greenhouses or cloches before strong winds hit. The moist sea air also encourages mildew and blight, so improve airflow around vegetables and fruit trees by removing old foliage.
