Suitable plants for shallow trough
Last year we had new decking installed which has a narrow wooden trough all along one side. The trough has holes drilled in the bottom but is quite shallow and narrow - about 15cm deep by 15cm wide. Ideally I'd like to plant something that doesnt grow too tall (no more than 15-20cm high as the kids step over this sometimes to get into the garden and looks fairly natural and will spread of its own accord but not sure if I can do it in this space. It receives sun for most of the day. Any ideas really appreciated.