It is important to protect your garden from the cold weather, especially frost. A good method of doing this is to cover your plants with a frost blanket, which can be got from any garden centre or hardware shop.
If you have a pond in your garden make sure the water is turned off and all the leaves and algae are cleaned out.
Rake up all those leaves from your garden that have fallen over the last month or so as this will brighten up your garden once again.
There are lots of Christmas flowers available from your garden centre at this time of year, so drop in and check them out. One of the most famous Christmas plants is the poinsettia, an indoor plant.
There are certain plants that need cutting back at this time of year. A good idea is, again, to check with your local garden centre for some expert advice.
It is also nice to decorate your garden for the Christmas season - you could put a Christmas tree in your garden and cover it with lights; you can also put some colourful Christmas lights and ornaments around your garden as this adds a nice festive feeling. But make sure to get a qualified electrician to install all your outdoor lighting.
If you are looking for a present for the gardener in your life, you could get a few pretty plant labels in, say, slate or terracotta; a selection of seeds to keep them busy in the New Year; or a new pair of secateurs to help with the spring pruning work.
Also don't forget about the birds this Christmas. Put up some bird feeders and fill them with nuts or seeds, which you can get in garden centres, supermarkets and hardware/pet shops. Be generous - it is a small price to pay for the wealth of birdlife that will be attracted to your garden in the cold weather.