Talkback: Plants for green roofs with soil depth of 50mm

Hmmm. The other plants are lovely and would be very suitable for this, but am not sure about the Acaena. It should only be a monoculture plant as it sends multiple wiry tendrils everywhere, swamping competition. It is generally brown and rather dead looking with burrs meaning it uses you to spread its seeds throughout the garden. Unattractive and thuggish - not the very best qualities,I think.