Open today 9:00 - 17:00
Open today 9:00 - 17:00
September marks the transition from summer into autumn, but warm soil and generally increasing moisture make it an excellent month for planting and dividing. Harvesting is still in full swing, while shortening days and cooler nights signal the time to start autumn lawn care, plant spring-flowering bulbs and begin preparing the garden for the season ahead.
Start planting daffodils, crocuses, hyacinths and other spring-flowering bulbs in borders and containers. September is particularly good for daffodils, while tulips can usually wait until later in autumn.
September is a good time to plant hardy perennials while the soil is still warm and autumn rainfall can help them establish. Keep newly planted perennials watered during dry spells.
Move wallflowers, foxgloves, honesty and other biennials raised earlier in the year into their flowering positions. Planting now gives them time to establish before colder weather arrives.
Hardy annuals including cornflowers, poppies and calendula can be sown outdoors where they are to flower. Autumn sowing can produce earlier flowers next year, although success will depend on the plant and local winter conditions.
Lift and divide overcrowded clumps of suitable herbaceous perennials once flowering has finished. Replant healthy divisions promptly and water them in well, particularly if September remains dry.
Continue deadheading dahlias, roses, penstemons and other plants that are still flowering. Removing faded blooms can encourage them to keep producing flowers into autumn.
Cut back herbaceous perennials that have collapsed or finished for the year, but there is no need to clear every border. Healthy stems and seedheads can provide winter structure, food and shelter for wildlife.
Apples and pears are reaching harvest time, along with crops including plums, blackberries and autumn-fruiting raspberries. Harvest individual varieties when ripe rather than relying on the calendar alone.
Once summer-fruiting raspberries have finished cropping, cut the old fruited canes down to ground level. Tie in strong new canes, which will carry next year’s crop. Do not cut down autumn-fruiting raspberries at this stage.
Maincrop potatoes can be lifted as the foliage dies back and the crop reaches maturity. Potatoes intended for storage should be lifted carefully in dry conditions, allowed to dry and checked for damage before storing.
Continue picking runner beans and French beans while they remain productive, along with courgettes, tomatoes and other late summer crops. Regular harvesting helps many productive plants keep cropping for longer.
Plant onion sets specifically intended for autumn planting for a crop next year. Newly planted sets may need temporary protection from birds until they have rooted firmly into the soil.
There is still time to sow suitable varieties of spinach, winter lettuce, rocket and other fast-growing salad leaves. Growth will slow as temperatures and daylight fall, so earlier September sowings generally establish more readily.
As conditions become cooler and damper, September is a useful time to repair summer wear. Scarify lawns with excessive thatch and aerate compacted areas once the soil is moist but not waterlogged.
Reseed worn or bare areas when the soil is warm and moist enough for grass seed to germinate. Keep newly sown areas watered if rainfall is insufficient and avoid heavy use while the grass establishes.
Lawns growing poorly can be given a lawn feed specifically formulated for autumn use. Avoid high-nitrogen summer feeds, which encourage soft leafy growth rather than helping the grass prepare for colder conditions.
→ Read our guide on organic lawn care and see our seasonal lawn care calendar
Do not assume autumn rain will provide enough water for recently planted trees, shrubs and perennials. Check the soil during dry periods and water thoroughly where needed while roots establish.
Do not allow container-grown camellias, rhododendrons and other ericaceous plants to dry out during prolonged dry weather. Flower buds for the following year are developing during late summer and early autumn.
Remove diseased plant material and vegetation that is collapsing onto neighbouring plants, but avoid stripping borders unnecessarily. Leaving some healthy seedheads and stems provides food and shelter for garden wildlife through autumn and winter.
As temperatures and light levels fall, remove or reduce greenhouse shading when it is no longer needed. This allows plants to make the most of the decreasing autumn light.
Clear away old plant material and clean growing areas before tender plants are brought under cover for autumn and winter. Check glazing and other greenhouse fittings while access is still easy.
Clear leaves from ponds as they begin to fall or fit netting before leaf fall becomes heavy. Leaves left to decay in the water can reduce water quality, but check netting regularly to ensure wildlife cannot become trapped.
Visit us in Kington. September is a useful time to choose spring-flowering bulbs, hardy perennials and autumn planting supplies, as well as seeds, lawn care products and tools for the jobs ahead.
