I have acquired some scrap decking from a friend, the intention being to make a large-ish garden planter. There's enough to make about a 4ft by 6ft box, around 8-12 inches deep. It is going in a reasonably shady patch with minimal topsoil (bloody new build properties with their building waste-filled gardens). My questions:
Is this a reasonable size?
What soils do I put in?
What plants thrive in the shade and are pretty to look at?
Can you tell I'm a novice?!