Jobs to do in the garden in September – Maintenance, planting and harvesting

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  • We show you the jobs to do in the garden during September, from collecting seeds to cutting back foliage

    With Autumn approaching and summer almost over, there is plenty to do in the garden to get ahead before the cold, harsh winter months. Here are the jobs you should be doing in the garden in September.

    Still catching up with August gardening jobs? READ: Jobs to do in the garden in August – Pruning, planning and putting your feet up

    1. Maintain your vegetable garden

    Jobs to do in the garden in September

    Image credit: Tim Young/Country Homes and Interiors

    Clear stems and leaves from vegetable beds and sow final crops of lambs lettuce and oriental salads (the latter can also be sown as an edible green manure, instead of covering beds with compost if you are otherwise going to leave them fallow for a season).

    Water tomatoes, beans and courgettes sparsely as their production period is coming to an end; continue to water autumn and winter vegetables regularly. Make sure you harvest fruit and vegetables regularly this month; leaving crops on the bough can lead to rot and disease setting in.

    2. Continue to collect seeds

    Jobs to do in the garden in September

    Image credit: Polly Eltes

    It is best to harvest and store your own seeds in the middle of a sunny day, when moisture levels are at their lowest. Only harvest ripe seeds that look hard and brown. Store them in paper bags or envelopes; label these with the name of the plant and the harvest date, then snip the seed head off and place the whole thing into the envelope. When you are ready to sort, working envelope by envelope, tip the contents onto a tray and gently remove any chaff. Tip the seeds back into the envelope, seal and store in a dry container.

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    3. Lift and divide summer-flowering perennials

    Jobs to do in the garden in September

    Image credit: David Brittain

    Dividing these plants will help to re-energise them, encouraging them to reboot, to grow back next year with more vigour and true to form once more. If any or all of the plants look as though nothing will restore them to their former glory – although one hopes the latter will not be the case – then be ruthless and take them out altogether and replace them with something else.

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    4. Sow and plant now for colour and healthy plants next spring

    Jobs to do in the garden in September

    Image credit: Annaick Guitteny

    To guarantee you have flowering trees and plants in your garden next spring, you need to sow and plant this autumn. Doing the work yourself now, and watching things grow, will not only save you money (buying seed to sow and grow now is far cheaper than buying plants next spring that have been grown by someone else), it will provide you with healthier plants and the pleasure of knowing you have created your spring garden yourself.

    For inspiration, expert advice, tips and free planting cards to take home, join one of the RHS Autumn Planting for Year-round Colour days at RHS Wisley, Rosemoor, Hyde Hall and Harlow Carr during September, October and November; visit the RHS

    5. Order small ornamental bare root trees

    Jobs to do in the garden in September

    Image credit: Rowan Isaac

    As with plants grown from seed, bare root trees and shrubs (the roots are visible) tend to be healthier and cheaper to buy. Bare root plants should be planted between November and March but you can place your orders with nurseries now. Soak roots in water until you have dug your hole or trench, if you are planting a hedge, and are ready to place them in the ground. Set the plant into the hole, backfill and heel in the soil. Water thoroughly and leave to settle, then water again and mulch.

    6. Plant small ornamental trees this winter

    Jobs to do in the garden in September

    Image credit: Jon Bentley

    Malus ‘John Downie’: native crabapple with good autumn colour and edible fruits that are good for jams and jellies, apple sauce and as a part-ingredient in cider. Enjoys heavy clay but will do well in any moderately fertile, moist, well-drained soil and while it can tolerate some shade, prefers full sun.

    Corylus maxima ‘Kentish Cob’ (Filbert): native hazelnut with yellow-green catkins in early spring and abundant cobnuts from September. Self-fertile, it does not need a pollination companion; enjoys sun or partial shade.

    Cercidyphyllum japonicum (Katsura tree): dome-shaped tree with good autumn colour and foliage that produces an aroma of burnt sugar as the season continues. Enjoys deep, fertile and moist loam with full sun but does not enjoy late frosts.

    7. Clip, cut back and use foliage

    Jobs to do in the garden in September

    Clip hornbeams and give beech hedges their second clip of the year. You can also start to tidy and cut back plants grown for cutting, and make the most of the glorious foliage, hips, berries and haws in flower arrangements.

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    8. Harvest early apples

    Jobs to do in the garden in September

    Image credit: Homes & Gardens

    This early in the season, eat them now and enjoy their rich, fresh flavour; a homegrown apple should be in every coat pocket, picnic hamper or lunchbox this month.

    9. Plant now for Christmas

    Jobs to do in the garden in September

    Image credit: Mark Scott

    In addition to planting your spring-flowering bulbs outside, now is the time to start preparing indoor plants that will flower in time for Christmas. If you are going to give them as presents, enjoy the process not only of planting up but of choosing the container and the plant to suit, to create the perfectly personalised present. Fragrant hyacinths, hippeastrum and narcissi are easy to grow but you could also try poinsettia and cyclamen and orchids.

    Want to get ahead: Jobs to do in the garden in October

    Will you be tackling any of these September gardening jobs?

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