Top jobs for September

1. Collect and sow seed from perennials and hardy annuals.

2. Clean out greenhouses so that they are ready for use in the autumn.

3. Start to reduce watering of houseplants as light levels drop.

4. Order spring flowering bulbs.

5. Take semi ripe cuttings of evergreen shrubs if you want to propagate them.



• What some people call a weed others call a wildflower – if you like it then why not look for the seed heads to ripen then pluck off the heads and shake them over a chosen area where you would like to have wild flowers next year. Poppies for example take easily from casual sowing like this. Same applies to your more traditional perennials.

• Buy or order spring-flowering bulbs. Daffodils are traditionally planted September/early October for best results. Tulips are best left until November. There are many other bulbs to choose from so visit our garden centre to see whats available.

• Its okay to plant new perennials as the ground is still warm and moist but they will have time to establish before winter. You can also buy spring-flowering bedding plants such as Bellis, Primula, wallflowers, and violas.

• Continue cutting back any perennials that are fading and dying down.

• Deadheading plants such as Dahlia, Delphinium and Penstemon will prolong the display and give colour well into the month.

• Clear away faded summer bedding plants and plant out Pansies, Wallflowers and other spring bedding plants

• Your hanging baskets will also benefit from a little deadheading and feeding to keep them going until mid-autumn.

• Divide any overgrown clumps of alpines and herbaceous perennials (such as crocosmias) to invigorate them and improve flowering next year.

• You can still apply weedkillers to kill most perennial weeds.  



• Put fruit nets on late fruiting varieties of Raspberries and Blackberries and remember to check regularly that they are firmly attached.

• Harvest early fruiting varieties of Apple and eat immediately as they do not keep very well.

• Plant out new Strawberry beds and remove runners from any new plants.

• Complete the pruning of Tay berries, Loganberries, Raspberries and Blackberries.

• Check stakes and ties on fruit trees and replace if they are worn or rotten.



• Lift onions and dry them before storing them.

• Harvest plants as soon as they are ready to get maximum flavour from them.

• Cut and dry herbs for use in the winter.

• Continue to take precautions against slugs and snails.

• Regular hoeing will keep weeds down and prevent seeds being dropped on to the soil to create problems for the following year.  



 • The weather is still suitable for creating and repairing new lawns with turf or seed. But you are running out of time to use lawn weedkillers to control perennial weeds such as daises and buttercups.

• You may need to strengthen your lawn for winter by applying an autumn lawn feed which is high in potassium to strengthen the roots. Avoid using old summer feeds as these are high in Nitrogen which at the wrong time of year could encourage lawn diseases.  


Greenhouse, Sheds and Houseplants

• Once tomatoes and other greenhouse crops are over, give the greenhouse a thorough clean to prevent pests from making a home in that lovely warm environment, ready to leap into action next spring.

• If you use your greenhouse then remember to clean it before you fill it with plants you want to protect from frost over the winter. Hose it down and then use a safe cleaning product such as Citrox to kill off any pests.


Trees, shrubs, climbers and hedges

• Shrubs that flowered early in the year (Camellia and Rhododendron) should continue to be well watered to ensure a good flower display next spring.

• Remember to use recycled water wherever possible.

• Prune climbing roses once they have finished flowering, cutting sideshoots back a couple of buds from the main frame.

• Late-summer flowering shrubs such as Helianthemum (rock rose) can be pruned this month. As a very general rule prune flowering shrubs either before or after they have flowered.

• Take hardwood cuttings of roses.

• Keep trimming hedges as required to keep them tidy.

• If there are strong winds, beware of falling trees. Trees that still have their leaves are easily blown over in strong winds - especially as wet soils make trees less stable.


Soils, mulching and weed control

• Keep weeding; most perennial weeds are susceptible to weedkiller this month and systemic weedkillers will carry on working throughout the winter. Also clear any debris and diseased material from your garden. Pests and diseases that overwinter in your garden will reappear next spring with a vengeance so get rid of them now. Burn diseased material and put the rest of your garden rubbish (apart from woody stems) in the compost.

• If your soil is heavy clay, start digging it over now whilst it is still relatively dry. Add plenty of organic matter to improve the quality and pea shingle to improve the drainage. It can be left in a pretty rough state over the winter when the cold will break the lumps down, making spring planting infinitely easier!



• Submerged oxygenating plants may need thinning out as they can quickly build up and fill the pond.

• Remove dead leaves from waterlilies as the leaves die back. Now is also a good time to divide waterlilies (and other pond plants) to increase your stocks and control vigorous growth. Ideally planting should cover no more than 50% of the water’s surface.  


Plants which are at their best in September

Crocosmia (Montbretia)


Sedum herbstfreud

Sedum Autumn Joy

Aster novibelgii varieties (Michaelmas Daisy)

autumn glory

Schizostylus (Kaffir Lily)

Gentiana (Gentian)

Hemerocallis (Day Lily)