Posted: 24/11/2015 at 16:53
I would mug up on plants and the conditions they like and the heights of them from books and Google but not plant anything until Spring. Conifers make soil dry and remove goodness from it. Have you dug in lots of compost and manure?
Draw out plans of your bed and choose plants you like, putting the shade lovers in the shadier places, taller plants and shrubs at the back. Don't put everything of the same height together, triangle shapes look better.
Then in the spring the Garden centres will have much more choice and you will be more knowledgeable. Also less risk of plants dying in winter cold and wet.