I create projects for Primary Schools and these are free for schools to download and use. I want to help schools create Bumblebee 'walls'. This will be hanging tubs/containers containing flowers which will attract bumblebees. All this has to be as low cost as possible to allow budget strapped schools to participate. So what flowers, grown from seed would be likely to be 'best value' for schools, i.e lots of flower looking good in a hanging container?