Gardening in September: What to plant and tidy in your garden this month

There is still time to enjoy ripening crops, but it's time to plant hedges, lift potatoes and forage fruit

Gardening in September: What to plant and tidy in your garden this month
Make the most of late-summer abundance as we slip into autumn  Credit: Christopher Pledger

The last of summer days are fizzling away but not without a final flourish. Ripe tomatoes jostle for space on vines, and corn, tender and bursting with colour, is starting to emerge from its green blanket to be barbecued or roasted.

In September, there might be hot days that require a t-shirt and soft drink; while some mornings will be spent in a light jumper, trimming wilting roses and picking the last of the summer soft fruit. There is still plenty of time to enjoy the abundance of the lighter months, but now is the time to think about change-over jobs. Take a look at the list below for some inspiration. 

Ripen tomatoes

Avoid blackening tomatoes with the help of some garden fleece and a polytunnel Credit: Getty Images

Outdoor tomatoes are in danger of blackening overnight without protection, but experiment with cutting them down from their supports and laying them on fleece before you cover them with a polythene tunnel, so the fruit can continue to grow and ripen for a few more weeks. We had success with that here last year and had at least three more weeks from our outdoor vines. You can ripen tomatoes by covering them with a polythene tunnel. 

It's not too late to sow wallflowers 

Contrary to popular belief, you still have some time to sow wallflowers, like these Erysimum wallflowers, pictured  Credit: Alamy Stock Photo

I always used to think September was too late to sow wallflowers, but last year we direct-sowed them in the first week of the month and, with no transplanting till spring, they did very well. Ideally, sow them when you want them to flower and add tulips in between in a couple of months’ time for a fabulous spring show.

Remove shading from the greenhouse so plants benefit from maximum light. Temperatures can still be quite high, so make sure there is adequate ventilation during the day and shut everything up at night.

Lift potatoes

Late-season potatoes are great barbecued with some putter and paprika  Credit: Andrew Crowley

Lift main crop potatoes before the slugs get the best of them and well before the frosts spoil the tubers. Lift tubers and dry them for a couple of days in the dark. Crumble any soil left on them, but don’t wash them. Store in a hessian sack, cool and dark.

Home houseplants

Any houseplants that have spent the summer outside can now come back indoors. If the plants are a manageable size, tip them out of their pots and check for unwanted visitors, such as slugs or ants. Put them back in their pots and top dress with fresh compost.

Forage fruit

Apples will be ripe and delicious, so take the kids on a foraging hunt to make homemade apple crumble  Credit: Jeff Gilbert

It’s blackberry time. Go on a hedgerow forage and then spend an hour or so making a delicious blackberry and apple pie, remembering to slot in a few leaves of scented geranium just under the pastry crust if you have them in the garden.

It is the start of the main apple and pear-picking season. Apples are ready when they part easily from the tree, whereas pears can be picked while they are still hard. Bring these in and ripen them indoors. 

Time to order hyacinths and narcissi

If you fancy hyacinths and paper white narcissi in your house at Christmas, order now. The beetroot-coloured 'Woodstock’ is my favourite hyacinth, but it’s the dark blues that have the strongest fragrance.

Drink a blackberry

Xanthe Clay's bottled apple and blackberry recipe is bursting with flavours.  Credit: Andrew Crowley

Make a blackberry shrub – a drink, not a plant. Combine 500ml blackberries with 2 tbsp set honey and 125ml cider vinegar. Put the fruit in the bottom of a storage jar. Warm the honey with the vinegar, so the honey melts. Pour into the jar, crush the fruit and mix. Leave for four days, or longer if you put it in the fridge. Strain and use in cocktails or with sparkling mineral water. Or, you wanted to see some more inspirational recipes for late-summer fruit, see Telegraph food columnist Xanthe Clay's guide to bottling apples, pears and berries

Plant a hedge

September is a good time for planting hedges. The soil is still warm and there is usually plenty of rain. It’s traditional to plant a mixed native hedge in the spring, but we’ve had success with autumn planting here. Evergreen hedging can be planted now, too, but don’t leave this any later than October as plants may be damaged by frost.

 You've still time to...