September brings a shift in the garden - colour deepens, late bloomers take centre stage, and there's a real mix of harvesting and forward planning to get through.
Here's Your September To-Do List
1. Lift your maincrop potatoes. Chop back the foliage first and give it a week or two before digging in. Kids usually love this one. Let the potatoes air-dry for a few hours before bagging them up in paper or hessian, and dig carefully so you don't nick any skins if you plan to store them.
2. Finish off the beans. Keep harvesting French and runner beans while they're going, then cut the plants right down at soil level - leave the roots in place so they can feed nitrogen back into the ground.
3. Prune your summer raspberries. Take the canes that fruited this year down to the base, and tie in the fresh growth - that's what will fruit next summer. If you are looking to add new canes to your fruit patch or expand your crop, follow our step-by-step guide to planting raspberry canes.
4. Get harvesting in the orchard. Plums, pears, apples, blackberries and autumn raspberries are all coming ready this month, so there's plenty to bring in.
5. Plant garlic and autumn onion sets now for a head start next year. It's also worth sowing spinach and spring onions, covering the young seedlings with fleece to keep off any early frost.
6. Get biennials in the ground. Wallflowers and Sweet Williams need time to establish before the cold sets in if they're going to flower well next year.
7. Sow hardy annuals. Nigella, poppies and cornflowers sown now will flower earlier next year than anything sown in spring. Learn how to sow and grow hardy annuals in our detailed guide.
8. Don't let up on deadheading. Dahlias, roses and penstemons will keep flowering well into autumn if you stay on top of it.
9. Cut back fading perennials - but leave some hollow stems standing, as they make useful winter shelter for insects.
10. Divide overcrowded clumps of geraniums, hostas and daylilies. It gives tired plants a new lease of life and hands you free plants to fill gaps elsewhere.
11. Plant new perennials while you can. The soil's still warm from summer and rain tends to be more reliable, so September is a great planting window. If you're looking for inspiration on border plants, read our advice on choosing and planting herbaceous perennials.
12. Start planting spring bulbs - hyacinths, daffodils and crocuses can go in now. Hold off on tulips until November, since cooler soil lowers the risk of tulip fire.
13. Give the lawn some attention. Scarify, aerate, and follow these simple tricks to keep your lawn in tip-top condition using a potassium-rich autumn feed to toughen the grass up before winter arrives.
14. Keep camellias and rhododendrons watered this month - they're forming next year's flower buds now.
15. Clean up the greenhouse. As daylight fades, wash off any shading paint or take down blinds to let more light through.
Need inspiration for your garden? Read our full guide on garden plants to plant in September to find the best varieties for autumn colour and growth.
Ready to get stuck in?
September is one of the busiest and most rewarding months in the garden calendar. Tackle a few of these jobs each week and you'll head into autumn with a tidier plot, a well-fed lawn, and everything in place for a strong start next spring. Pop into us at Carpenters Nursery in St. Albans for seeds, bulbs, feeds and anything else you need to tick off your list.
