​Jobs to do in the garden in September

​Jobs to do in the garden in September – Maintenance, planting and harvesting
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The bulk of the summer is behind us, and even this week we have seen the weather change and feel a little cooler – though are gardens will be grateful for the rain. September is almost here are there are a number of jobs that need to be done, from collecting seeds to cutting back foliage.

There is plenty to do in the garden this month to get ahead before the cold, harsh winter months. Here are the jobs you should be doing in the garden in September.

Top gardening jobs for September

• Divide herbaceous perennials
• Collect and sow seed from perennials and hardy annuals
• Clean out greenhouses so that they are ready for use in the autumn
• Order spring flowering bulbs.
• Take semi ripe cuttings of evergreen shrubs if you want to propagate them.
• Clear stems and leaves from vegetable beds.
• Sow final crops of lambs lettuce and oriental salads
• Water tomatoes, beans and courgettes sparsely as their production period is coming to an end.
• Continue to water autumn and winter vegetables regularly.
• Harvest fruit and vegetables regularly this month; leaving crops on the bough can lead to rot and disease setting in.

 
Lawn Care
- 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 weed killers 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. 
 
Lift and divide summer-flowering perennials
Dividing these plants will help to re-energise them, encouraging them to reboot, to grow back next year with more vigour and true to form once more. If any or all of the plants look as though nothing will restore them to their former glory – although one hopes the latter will not be the case – then be ruthless and take them out altogether and replace them with something else.
 
Trees, shrubs and climbers

• 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.

 
Continue to collect seeds
It is best to harvest and store your own seeds in the middle of a sunny day, when moisture levels are at their lowest. Only harvest ripe seeds that look hard and brown. Store them in paper bags or envelopes; label these with the name of the plant and the harvest date, then snip the seed head off and place the whole thing into the envelope. When you are ready to sort, working envelope by envelope, tip the contents onto a tray and gently remove any chaff. Tip the seeds back into the envelope, seal and store in a dry container.
 
Sow and plant now for colour and healthy plants next spring
To guarantee you have flowering trees and plants in your garden next spring, you need to sow and plant this autumn. Doing the work yourself now, and watching things grow, will not only save you money (buying seed to sow and grow now is far cheaper than buying plants next spring that have been grown by someone else), it will provide you with healthier plants and the pleasure of knowing you have created your spring garden yourself. For inspiration, expert advice, tips look at the RHS website.

• 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 a garden centre to see whats available.
• It's okay to plant new perennials as the ground is still warm but moist and 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.
• 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 weed killers to kill most perennial weeds.

Greenhouse and Houseplants

• 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 to kill off any pests.
• Replacing broken glass in your greenhouse is a good idea before the serious rain sets in. Fix leaky shed roofs for the same reason.

Final job, if you still have the energy
If the weather dries up take advantage of it by painting fences, sheds and other wooden structures with a preservative.