15 garden tips for September

As September arrives, the garden starts to glow with rich colour, and late-flowering plants look stunning in the soft autumn light. With fruit and veg to harvest and plans to be made for spring, there’s no shortage of jobs to do, and here are our top 15 gardening jobs for September.

Top 15 gardening jobs for September

1. Cut off the foliage on maincrop potatoes and wait a couple of weeks, then start digging up the potatoes – kids will love this job! Leave the potatoes to dry for a few hours before storing them in paper bags or hessian sacks. (Take care not to damage the potatoes when digging them up, if you want to store them.)

2. Keep picking the last of your French and runner beans, then cut the plants down to ground level and leave the roots to release their stored nitrogen into the soil.

3. Prune summer raspberries, cutting down the fruited canes to ground level. Tie in this year’s new growth to support – these stems will bear next year’s fruit.

4. It’s a fruit bonanza in the orchard this month! Plums, pears, apples, blackberries and autumn raspberries are all ready to harvest now.

5. Plant autumn-planting onion and garlic sets for an earlier crop next year. Plan for spring by sowing spinach and spring onions, and covering the seedlings with fleece to protect them against frost.

6. Plant out biennials like wallflowers and Sweet Williams, giving them time to settle in before winter, ready to flower next year.

7. Sow hardy annuals like nigella, poppies and cornflowers for a fabulous late spring display – they’ll flower earlier than annuals sown next spring.

8. Keep up the deadheading – late summer stalwarts like dahlias, roses and penstemons will keep on flowering into autumn if regularly deadheaded.

9. Cut back perennials as they start to fade, remembering to leave a few hollow stems standing to provide homes for insects over winter. 

10. Lift and divide overgrown clumps of geraniums, hostas and daylilies. As well as rejuvenating the plants, this also gives you a free supply of extra plants to fill any gaps in the garden.  

11. September is a good month to plant new perennials, while the soil is still warm from summer, and there’s likely to be plenty of rain to keep them watered.

12. Start planting spring bulbs like hyacinths, daffodils and crocuses. Wait until November to plant tulips, as the colder temperatures reduce the risk of the bulbs being affected by viruses like tulip fire.

13. Now’s the time to do lawn maintenance. Scarify, aerate and feed your lawn, using an autumn lawn feed high in potassium which will help to harden the grass before winter.

14. Keep camellias and rhododendrons well-watered this month while they develop their flower buds for next year.

15. As light levels drop, wash any shading paint from greenhouse windows or remove blinds.

Get your garden ready for next year with our wide range of seeds, plants and garden equipment. Come in and see us today!