Posted: 09/03/2014 at 12:35
Bsy Lizzies (Impatiens) are ideal for shade and you can pick them up quite cheaply at GCs, nurseries and DIY stores for a summer display to go with the Sarcococca Ceres mentioned. Lots of colours. Osteospermums (Cape daisies) will grow in the window boxes - they're easy to get too like the Busy Lizzies and plenty of colours available. They're both annuals so will only last through the summer/early autumn. Primulas and Polyanthus will grow in shade and you can pick them up now. Some of mine flowered on and off all summer and winter. You can get small ivies to trail from the window boxes as well. I got some for a £1 in Morrisons recently. In autumn you could put some early bulbs - daffs and crocus - in pots or the window boxes once any annuals are finished. They'll give you some nice colour at this time of year and are inexpensive. In fact, you'll get little pots of daffs cheaply just now in Garden Centres.
Did you want a few more evergreens to give structure? You could get some box balls or cones which you could take with you if you move and they will give you something to look at in winter along with the Sarcococca (Christmas box)