Organic Gardening - what to sow in September

September marks the start of autumn, a time to enjoy late blooms, prepare for winter, and start planting for next spring. This month, focus on harvesting produce and tidying up.

Flowering Plants

Flowering Plants

  • Sow hardy annuals like cornflowers and calendula for early blooms.
  • Direct sow wildflower seeds onto light, sandy soils this month.
  • Plant spring bulbs like daffodils, crocuses and hyacinths.
  • Plant allium bulbs for striking flowers in late spring.
  • Cut back faded summer-flowering perennials.
  • Take cuttings from tender geraniums and fuchsias to overwinter in a sheltered greenhouse.
  • Plant winter bedding like pansies and violas for autumn and winter displays.
  • Divide clump-forming herbaceous irises.

Vegetables

Vegetables

  • Sow leafy greens like winter lettuce, spinach, and chard.
  • Plant autumn garlic cloves in well-drained soil.
  • Sow hardy broad bean varieties for an early spring harvest.
  • Start spring onions from seed in a greenhouse or cold frame.
  • Plant autumn onion sets for a head start.
  • Sow pak choi and Asian greens for autumn cropping.
  • Harvest late potatoes and store in a dark, cool place.
  • Pick any remaining green tomatoes to ripen indoors or make chutney.

Fruit

Fruit

  • Begin planting currant and gooseberry bushes.
  • Harvest apples, pears, and plums as they ripen.
  • Net fruit bushes to protect against birds, but check them often.
  • Move fallen or overripe fruit to a quiet area of the garden to feed the birds.
  • Mulch around the base of berry bushes to retain moisture.
  • Harvest late blackberries and raspberries and freeze any surplus.
  • Feed strawberry plants after the final harvest using a balanced fertiliser.

General Garden Jobs

General Garden Jobs

  • Clear leaves from lawns to prevent dampness and moss buildup.
  • Start turning your compost heap to accelerate decomposition.
  • Clean and store garden tools for winter.
  • Use a net to keep ponds clear of fallen leaves and other debris.
  • Remove weeds to keep borders tidy.
  • Collect seeds from the dry seedheads of flowering plants.
  • Ventilate greenhouses on warm days.
  • Cut back overgrown shrubs to maintain shape.

Pots & Containers

  • Replant containers with autumn bedding plants like polyanthus.
  • Move tender container plants indoors before frost.
  • Reduce watering as temperatures begin to cool.

Wildlife

  • Make a log pile using untreated logs to provide shelter for insects.
  • Create a mini-wildlife pond if you don't have one.
  • Leave some seed heads on plants as winter bird food.

Pruning

  • Cut back spent growth on perennials.
  • Cut back summer fruiting raspberry canes (floricanes) after they finish producing berries.
  • Lightly prune fruit bushes to remove overcrowded stems.

Organic Gardening Tip: Sow green manure seeds in empty beds. This protects the soil from erosion, suppresses weeds, and adds nutrients when turned back into the soil in spring.

Sophie Essex

Written by: Sophie Essex, garden writer

Sophie Essex is a freelance garden writer with a passion for horticulture and environmental conservation. She's qualified with a BSc in Botany/Plant Biology from the University of Plymouth and a MSc in Biodiversity and Taxonomy of Plants from The University of Edinburgh.

Sophie has also worked as a professional gardener and landscaper, developing her practical skills at Cornwall's Eden Project, the National Trust for Scotland, and the Royal Botanic Garden Edinburgh.