This monthly guide, put together by Wisley Plant Centre's horticultural experts, is geared to London gardens and their unique conditions, such as our urban microclimate - and limitations, such as lack of time - so don't expect irrelevancies on how to grow cabbages.
These insider tips will be aimed at your lifestyle. Your windowboxes will never look better.
Need to do in your garden this month
* Cut back your buddleja after summer flowering. Aim to take away half to two-thirds of the plant's branches.
* Make sure that, as old foliage starts to die down, you remove it to stop fungal diseases being 'hosted' on the plant over winter. Make sure all diseased parts of plants are removed, to stop it being a problem next year.
* Root some runners off the strawberry plants in containers that have finished fruiting. Peg the end of the runner onto a four-inch pot of John Innes Number Two compost mixed with some multipurpose compost. Leave to root over the autumn, and before severing from the parent plants, give them a tug to make sure they have rooted. Strawberries run out of steam after a couple of years in containers, so this is a good way of keeping fresh plant supplies in readiness.
* Sort out dodgy-looking patches of turf or lawn by raking out the build-up of dead grass and weeds. Spike the surface with a fork and then sprinkle over with lawn sand (you can buy it at the garden centre). Feed during autumn with a general lawn feed. You can expect a healthier lawn come spring.
* If you want to plant snowdrops, aconites or Anemone blanda from bulbs and corms, buy them now whilst they are still plump from being lifted. The longer they are out of the ground, the less likely they are to establish in pots and borders. A tip for anemone corms is to soak them overnight in tepid water before planting, to swell them up.
* Cut back summer-flowering heathers to allow the plants to produce fresh growth on which next year's flowers will develop. Give them a liquid feed.
* If roses have suffered from blackspot this season, rake up and remove all fallen leaves to stop the spores reinfesting the plant next spring. A weak drenching with Jeyes Fluid or Bordeaux mixture will kill off any spores already in the soil. Prevention is always better than cure.
* Make sure you check for pests and diseases when you bring plants back into the house or greenhouse when the weather turns. Eradicating any potential problems before the plants enter a warm haven could save you a lot of effort later.
* As summer-flowering bulbs come to an end, lift them and store in a frost-free place for the colder months. Remove any stems, and sprinkle sulphur powder where the stems were attached, to avoid any rot developing in the bulbs.
* Once you have finished weeding containers and borders, mulch with bark or compost to smother any emerging weeds. Mulching also helps insulate the soil through the colder weather.
Nice to do in your garden this month
* Make a collection of pots just outside your windows, filled with hardy autumn bedding such as pansies, so that even on dull, wet days you have a cheerful show of colour.
* Buy several hellebores for early spring colour. Many of the new varieties have been bred to carry their flowers facing outwards, making these beautiful blooms easier to admire. The label to look for is Harvington Hybrids, bred by hellebore experts Hugh and Liz Nunn.
* Plant prepared hyacinths in 4inch pots of compost to flower indoors before Christmas. Their noses should be proud of the compost. Leave in a cool, dark place to root fully before bringing indoors in December. Protect from frost, but don't bring into the warm too early.
If you prefer to use decorative bowls, use bulb fibre which is specially produced for containers without drainage. Prepared hyacinths need 12 weeks from planting to flowering, so will need to be planted by 24 September to produce flowers for Christmas day.
* Aida wallflowers are now available in the garden centres. Seek out these lovely autumn-flowering bedding plants in jewel shades. They will flower again in spring, so providing a double burst of colour.
* Plant up some herbs to make a fun display on your windowsill. Recyle some old tins by removing the labels, making drainage holes at the base and then planting up with some seasonal herbs. Lemon thyme, oregano, chocolate mint and tricolor sage will all sit happily through the winter, and you can pick off the leaves to use in the kitchen.
* For a smart and welcoming autumn hanging basket or doorstep container, plant up one carex evergold grass with several white mini cyclamen and silver variegated ivy. Deadhead the cyclamen to keep the flowers coming until after Christmas, tugging the stems from the bottom of the flower stalks to prevent rot entering the cyclamen corm.
* Plant saffron crocus bulbs now and you will see the golden stamens of saffron form in the purple flowers soon after. This spice has been used to flavour food for centuries, and weight for weight, is worth more than gold!
* There is still time to plant an autumn crop of radishes in pots to harvest in October. A good mix is Rainbow Mix from Thompson & Morgan, which has several different colours ranging from white and gold to purple, and crops in just 28 days.