If you visit the garden centre now you are likely to see the Christmas Rose in bloom. It is not actually a rose; it is a relation of the buttercup and will flower in December under the right conditions.
The best way to get a flowering plant in December is to buy one already in flower at the garden centre, as forcing them in December – although possible – requires experience. To have a go at encouraging this early flowering yourself though, grow in potting compost in a frost free greenhouse or sunroom. If you plant seeds in September you should see flowering by December. In the garden, they prefer a shady or partially shady area in rich, well-drained soil.
The Christmas Rose will grow to about 40cm tall and 45cm wide. If you aren’t seeing a good bloom, a general purpose fertiliser will help, along with mulching with leaf mould each autumn. You may also wish to prune some of the older leaves as the flower buds emerge, as they can cover the flowers. The Christmas Rose can be divided around September, but regrowth can be difficult and slow.