September is perhaps one of the busiest months of the year in the garden! It’s all hands to the pump as you start to clear the beds, harvest the veg and get ready for winter as the temperatures start to drop.
It’s time to plant autumn and winter veg, lay new turf, lift bulbs and do any essential greenhouse maintenance. You may have to dodge the showers later on in the month but that’s no excuse – there’s far too much to do to sit indoors with your feet up! Here’s our guide to what to do in the garden in September.
Your essential September checklist
- Plant up containers with cyclamen and heathers for autumn colour.
- Plant spring bulbs such as fritillaries, daffodils and crocuses, but wait until November to plant tulips.
- Plant prepared bulbs like hyacinths, hippeastrum and amaryllis indoors for beautiful Christmas flowers.
- Rake up fallen leaves and bag them up or store them in a pile to make leaf mould.
- Yew hedges can still be pruned in September, but leave other conifers till spring.
- Remove greenhouse shades and keep a close eye on the temperature to make sure any
sudden cold snaps at the end of the month don’t damage tender plants. Check that greenhouse heaters are in good working order.
- Treat veg beds and borders with Nemaslug Slug Killer nematodes to kill slugs before they lay their eggs.
- Check container plants for signs of vine weevil damage (notched leaves) and treat with Nemasys Vine Weevil Killer.
- Clean out rainwater butts and clear downpipes, ready for the winter rains.
- Give birdfeeders and bowls a good clean with a disinfectant to prevent the spread of a nasty disease called Trichomonosis or ‘fat finch’ disease.
- Lay new turf or sow lawn seed now, before the temperatures drop. Remember to keep off new lawns for a few weeks while they are getting established.
- Rake, aerate and feed existing lawns, and tackle moss with a moss treatment like Westland Moss Master.
- If you have a problem with leatherjackets in your lawn, treat them now with Nemasys Leatherjacket Killer.
Flower beds and borders
- Things are starting to slow down in the flower borders in September, but you can still encourage plenty of early autumn flowering by religiously deadheading.
- Fuchsias are at their best now, and it’s also the right time to take cuttings for next year.
- As the annuals start to die, pull them up and compost them to give your autumn-flowering plants plenty of room. Sow more hardy annuals like cornflowers, nigella, Ammi majus and poppies now, for next year’s flowers.
- Now’s a good time to plant perennials, shrubs and trees, while the soil is still warm. Plant some late-flowering plants like sedums, salvias and asters to support the bees and other pollinators.
- Lift gladioli corms and store them over winter in a dry, frost-free place.
- Lift and divide overgrown clumps of perennials, replanting the divided sections so that they have a chance to establish before the soil cools down.
In the veg plot
- Plant out spring cabbage seedlings.
- Sow green manure on empty beds to keep nutrients from washing out of the soil over winter.
- Plant autumn-hardy onion, shallot and garlic sets.
- Harvest leeks as you need them.
- Cut back foliage on squashes and pumpkins so the fruit can ripen fully.
- Lift maincrop potatoes.
- Keep harvesting sweetcorn, courgettes, cucumbers, chillies, French and runner beans.
- Pick autumn raspberries, and cut back the fruited canes of summer raspberries to ground level.
- Harvest apples, pears and plums, and pick up windfalls.