What To Sow And Grow In September

Posted in Garden

1 Sep
What To Sow And Grow In September image 1

What To Sow And Grow In September

September might be peak harvest time, but there’s still plenty to sow and grow this month.

Here's a handy list of what to plant in September, along with the flowers, fruits and vegetables you can grow this month:

Flowers To Sow And Grow

In The Greenhouse/Indoors

  • Surface-sow euphorbia seeds now in trays indoors.
  • Sow dierama seed now on the surface of moist compost. Keep in a cool greenhouse over winter.

In The Cold Frame / Under Cloches

  • Sow calendula seeds in pots now and keep in a cold frame, for fruity colour from early summer next year.
  • Sow violas in a cold frame to plant out in the spring.
  • Sow lupins, aquilegia, aconitum and hollyhocks in a cold frame now.
  •  Sow eryngium and echinops in pots and place in a cold frame this month to enjoy their silvery spiky foliage next year.
  • Start verbascum seeds off outdoors now in pots in a cold frame.
  • Sow perennial salvias into pots and trays outdoors and leave in a cold frame or unheated greenhouse through the winter.
  • Sow red hot pokers into pots and trays outdoors for stunning flowers next summer.
  • Sow helenium in a cold frame to attract bees and butterflies into your garden next year.

Direct Sow Outdoors

  • Sow Ammi Majous (Bishop's Weed) directly in the ground now where you'd like it to flower. Autumn sowing will produce bigger, more robust plants to grow.
  • Sow hardy geraniums outdoors and leave them to over-winter.
  • Direct sow hardy annuals, such as cornflowers, poached egg plant, annual poppies and larkspur, for bigger plants next year.
  • Sprinkle California poppies into your borders for stunning colour late next spring.
  • Direct sow Love-in-a-Mist (nigella) - it will over-winter quite happily and will self-seed prolifically!
  • Sow delphiniums this month for flowers next summer.

Plant Outdoors


  • Fill gaps in your borders with autumn-flowering plants, such as sedum and chrysanthemum, to extend the colour to the end of the season.
  • Plant hyacinth and amaryllis bulbs for forcing, to ensure a crowd of colourful blooms at Christmas. Keep them in a dark, cool place like a shed or garage and bring them indoors when the shoots are 5cm tall. Perfect for a homemade Christmas present!
  • Plant spring-flowering bulbs, such as daffodils, crocus and hyacinths.
  • Plant out any biennial plants sown earlier in the year. This includes foxgloves, wallflowers and violas.
  • Plant new perennials, trees and shrubs. Now is a good time as the soil is still warm and increasing rainfall should be on its way.

Vegetables And Herbs To Sow And Grow

In The Cold Frame/ Greenhouse/ Under Cloches

  • Direct sow spinach now and offer cloche protection as the weather cools. This will ensure harvests throughout autumn and winter.
  •  Sow spring cabbages, such as 'April' and 'Durham Early' into modules in the greenhouse.
  • Sow pak choi under cloches now for an autumn supply of baby salad leaves.

Direct Sow Outdoors

  • Sow corn salad (lamb's lettuce) now - it’s a fully hardy crop which can be sown outdoors now for cropping throughout the autumn and winter.
  • Sow 'green manures' on empty beds now to help improve your soil structure and prevent weeds establishing over winter.
  • Sow 'Hi Keeper' onions into a well-prepared seedbed - these are the best variety of onion for autumn sowing. Only thin your onion seedlings in the spring.
  • Direct sow salad leaves now.
  • Try sowing the very hardy 'Perpetual' spinach outdoors this month for winter harvests later in the year.
  • Sow winter-hardy spring onions, such as 'White Lisbon' and 'Performer' for crops next spring.
  • Make your last direct sowings of summer radishes this month - the cooler autumn conditions are ideal.
  • Sow turnip seeds into well-prepared beds this September, for small roots.
  • Sow winter lettuce, such as 'Arctic King', directly into the ground now.

Plant Outdoors

  • Start planting garlic bulbs at the end of the month for cropping next year.
  • Plant autumn onion sets this month.
  • Plant out any spring cabbages sown during the summer.

Keep One Step Ahead – What To Order This Month

  • Order sweet pea seeds to start in cold frames in October.
  • Buy in autumn onion sets for an early summer harvest next year.
  •  Order rhubarb crowns and asparagus crowns to plant next month.

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