SEPTEMBER IN THE GARDENAster_Monch_in_border_Oct_07_LMWHelenium 'Sahin's Early Flowerer'

This should be the time of mellow fruitfulness, so it’s time to enjoy the garden and fill in those gaps left by other plants that have gone over.  If you use perennial plants you won’t have the same gaps again next year, which will save money and effort in the long run.

What to do if you haven’t much time

  • Plant perennials for autumn colour and for next year. Try asters (there are now new, compact forms that don’t get mildew), rudbeckias and Japanese anemones
  • Deadhead perennials, bedding and basket plants
  • Mow lawns as required



Other jobs

Trees, Shrubs & Hedges

  • Move evergreen shrubs
  • Plant container-grown shrubs and trees – they’ll have time to start getting established before the winter, ready to grow fast in spring. Use Rootgrow when you plant to speed up this process and so improve their chances of surviving if we have another harsh winter
  • Start pruning climbing roses


  • Keep collecting seeds
  • Cut down and divide perennials, adding soil conditioner as you do so
  • Support tall-growing clumps of perennials such as asters



  • Plant spring flowering bulbs, including bulbs to naturalise in grass


Annuals and bedding

  • Sow hardy annuals
  • Lift tender annuals before autumn, for overwintering in a greenhouse or cool porch
  • Plant out spring-flowering biennials and bedding perennials such as sweet williams, wallflowers and foxgloves



  • Plant autumn containers – if done now, they’ll get going before the cold weather and look better all through the winter. Don’t forget to use a little controlled release feed like Osmocote.
  • Stop feeding permanent plants growing in containers. If you used controlled release fertiliser in the compost, it will slow down or stop releasing nutrients as the weather gets cooler.


  • Start mowing less frequently
  • Remove thatch from the lawn and aerate the soil if it’s compacted and drains poorly
  • Top-dress immediately after aerating
  • Treat broad-leaved weeds with a lawn weed killer
  • Established lawns can be fed now, with an autumn feed
  • Sow grass seed or lay new turf


Vegetables and herbs

  • Cut down asparagus foliage
  • Pick marrows, pumpkins and squashes
  • Begin lifting root vegetables
  • Get onions under cover to dry out and store
  • Sow a winter variety of lettuce
  • Plant out winter cabbages and autumn onion sets
  • Continue harvesting fruit; protect your crop from birds with netting
  • Prune blackcurrants


Under cover

  • Remove shading
  • Start preparing your greenhouse or polytunnel for winter – clean up all debris, disinfecting with Jeyes fluid or similar to cut down on overwintering of disease spores
  • Reduce watering and ventilation. Change to watering in the morning if possible, so plants don’t got to bed wet
  • Bring in tender plants
  • Sow the last spring cabbages