September is generally a cooler, gustier month than August and the days are noticeably shorter, but there’s plenty to be done while you’re outside enjoying the last of the year’s warmth.
Harvesting crops will keep you busy this month if you have a fruit or vegetable patch. It’s also time to get out and start planting spring-flowering bulbs for next year and you can collect seeds for next summer’s colour too.
General jobs to do in the garden:
- Net ponds before leaf fall gets underway
- Keep up with watering of new plants, using rain or grey water if possible
- Start to reduce the frequency of houseplant watering
- Late August and early September is the last time to prune Wisteria.
- Prune lavender into a tidy, compact and neat shape for next year
Jobs to do in the flower garden:
- Plant spring flowering bulbs
- Divide herbaceous perennials as the weather cools and water in the new divisions well.
- Collect and sow seed from perennials and hardy annuals
- How tall are your sunflowers? Leave them in situ for autumn bird food.
- Prune climbing roses and rambling roses once they’ve finished flowering (unless they are repeat-flowering varieties, in which case leave them until later in the year).
- Keep camellias and rhododendrons well-watered at this time of year to ensure that next year’s buds develop well.
- Continue to feed and deadhead hanging-basket and container plants – they will often keep going until the first frosts.
Jobs to do in the fruit & vegetable gardens:
- Dig up remaining potatoes before slug damage spoils them, on a sunny day. Allow to dry before storing somewhere cool, dry and dark.
- Some crops will need protection. Cover leafy vegetable crops with bird-proof netting
- There is still time to sow a few more greens to keep you in salad through the autumn. Try autumn sowings of lamb’s lettuce, mizuna, and other speedy seeds.
- Keep harvesting your fruit and veg, and either use them now or store them. With onions you can string them up, which ensures good air flow around them and enables you to store them for much longer.
- Pick autumn raspberries
- Short on fruit in your garden? Hit the hedgerows for blackberries great for jam, pies and wine.
- Pot up strawberry runners to make extra plants for next year.
- Pick off rotting fruits from pear, apple and plum trees – they will spread disease if left on the tree.
In the greenhouse:
- Clean out cold frames and greenhouses so that they are ready for use in the autumn to reduce the risk of pests and diseases next year
- Water greenhouse plants early on in the day so the greenhouse is dry by the evening.
- Close greenhouse vents and doors late in the afternoon to help trap in heat overnight.
- Remove shading from your greenhouse towards the end of the month so that plants get the maximum light available.
What to do with the lawn:
- Raise the height of your mower blades as grass growth slows down.
- Feed your lawn with an autumn fertiliser which is rich in potassium and low in nitrogen.
- Scarify your lawn with a rake to remove the thatch from your grass.
- Create a new lawn from turf or seed – autumn weather is favourable for good lawn establishment.