Organic Gardening - what to sow in August

August is a time to reap the rewards of summer growth, prepare for autumn planting, and keep the garden productive. Enjoy the peak of your harvest as your garden thrives.

Flowering Plants

Flowering Plants

  • Direct sow wallflowers, forget-me-nots, and biennial seeds like foxgloves.
  • Direct sow perennial lupins for blooms in spring.
  • Sow hollyhock seeds to flower next summer.
  • Collect and store seeds from favourite blooms as seed heads appear.
  • Trim lavender after flowering to maintain shape.
  • Deadhead dahlias and roses to prolong blooming.
  • Remove faded leaves on hostas and other perennials.
  • Towards the end of the month, lift and divide bearded irises.

Vegetables

Vegetables

  • Sow pak choi, kale, chard and spring cabbages.
  • Direct-sow carrots for an autumn harvest.
  • Sow hardy Chinese cabbage now for autumn and winter harvests.
  • Plant out leeks for winter crops.
  • Sow lettuce and rocket for late-season salads.
  • Start radishes for a quick, late-season crop.
  • Feed and water pumpkins and squash regularly.
  • Harvest garlic and onions, then dry in the sun before storing.

Fruit

Fruit

  • Harvest soft fruits like blackberries and raspberries.
  • Prune floricane raspberries by cutting the older canes that have finished fruiting. Tie in the short young green stems that will produce next year's fruit.
  • Train and tie in blackberry canes for next year.
  • Protect ripening grapes from birds by covering them with netting. Check it regularly.
  • Harvest early varieties of apples and plums.
  • Net strawberry beds to keep birds away.
  • Move any fallen, overripe fruit away from fruit trees to feed the wasps and wildlife.
  • Mulch blueberries with ericaceous compost.

General Gardening Jobs

General Gardening Jobs

  • Water potted plants every evening in warm weather.
  • Raise your mower blades in very hot weather to increase your lawn's resilience to drought.
  • Remove weeds from paths, borders, and beds.
  • Deadhead summer bedding and perennials.
  • Harvest vegetables regularly to keep plants productive and avoid gluts.
  • Ventilate greenhouses and check for pests.
  • Refresh pond water in hot weather and clear any algae.
  • Aerate compost heaps by turning regularly. Add a good mix of shredded green and brown to the heap to keep it composting happily.

Pots & Containers

  • Water pots and containers daily in warm weather.
  • Feed and top up hanging baskets and containers.
  • Deadhead flowering plants to encourage more blooms.

Wildlife

  • Cut back lavender, being careful not to prune into old wood.
  • Prune established peach and nectarine trees with clean, sharp secateurs to remove diseased wood and crossing branches.
  • Trim wisteria after flowering is over to encourage next years blooms. Reduce this year's growth to five leaves on a shorter stem.

Pruning

  • After flowering, prune wisteria side shoots to around 20cm or until only five or six leaves are left on each of this year's stems.
  • Prune berry bushes like currants and gooseberries to encourage airflow.
  • Trim lavender after flowering to maintain a compact shape.

    • Organic Gardening Tip: Improve soil quality by adding green manures such as mustard or clover. These enrich the soil, boost microbial activity, and set your garden up for autumn.

    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.