Green roof!
By Badger
United Kingdom 
Thanks all, I am a insect fanatic, and will try to create a Chalk downland roof, so any help and advice would be fantastic, Ive never worked with chalk soils
badger
badger
17 Jun, 2009
Answers
I saw a picture in a book recently and they'd used the yellow-leaved form of origano (along with other things). It looked really nice.
17 Jun, 2009
Some short grasses are supposed to do well on green roofs. Probably something like blue fescue that can withstand drought.
17 Jun, 2009
Remember you will need a tin roof and more supports underneath. Sedums are one of the best subjects to grow.
17 Jun, 2009
Certainley golden Sedum or Stonecrop Badger, we had it on our cottage roof when we bought it. I took it off and relocated it to the garden. A type of succulent with stunning yellow starry flowers all summer. I would think anything that needs a free draining site and can withstand drought too. How about looking at alpines, the Saxifrages would make soft matts of bright green with the added bonus of scarlet or white flowers in Spring.....:o)
I wouldn't use anything that would have flowers over6ins tall though.
17 Jun, 2009