Winter is approaching - we've had the first frosts which have blackened the Dahlia foliage and killed off the half-hardy Zinnias. My Cosmos seem to have escaped this fate owing to their height (over 6 ft this year!) and are still in full flower.
Once dahlias have been blackened by frost, it's time to cut them down and either dig them up for storage inside over the winter or to apply a thick mulch to protect them. Annuals which have given up the ghost should be removed and composted and empty beds given a covering of organic matter - compost or manure. It can be left on the soil surface for the worms to drag down and enrich the soil over the winter. Where I have planted out biennials, I just mulch around them.
As an avid watcher of predicted overnight temperatures, I dug up my frost-tender Chrysanthemums before any danger of frost. Late-flowering Chrysanthemums like the elegant 'Avignon Pink' don't start flowering until the end of October and will flower up until Christmas. You can either grow them in pots which can be brought in under cover or plant out over the summer and then carefully dig them up with an intact root ball and place them in large pots in a greenhouse/conservatory or potting shed. I find them really useful additions to fresh Christmas wreaths as they are very long-lasting flowers once cut.
I sowed some hardy '10 week' Stocks and Chinese Forget-me-nots late in June and these are still full of flower, so along with some Borage and Feverfew still in flower, a suprisingly summery jug of flowers can be picked even in November.
Viburnum tinus is a shrub that is overlooked for a lot of the year but come October/November it is flooded in fragrant white flowers. These are invaluable just when the herbs that I use for foliage/filler material in a vase (like Borage, Mint and Feverfew) are coming to an end. The baton is handed to this evergreen shrub for most of my winter flower displays and trimmings look good in a fresh Christmas wreath.