Chicken friendly ground cover plants for garden

[MyfficRaven]

We have a couple of chickens who spend some time every day free ranging in the garden. We also have a scruffy patch of earth by the shed which we are about to dig over, and put some ground cover plants in, the plan being to have evergreen cover, with a few smallish shrubs, and no bare earth. Can anyone recommend any evergreen ground cover plants that are chicken safe (ie non-toxic - although chicken proof would also be good!). If necessary we can fence off this section while they establish.

I've got some heather on my rockery that seems to survive their best efforts at destruction if that helps at all. I've also got a ground cover plant that spreads really quickly and has lovely pink flowers. Unfortunately I don't know what it's called which isn't quite as helpful! Will have a bit of a google to see if I can find out as the girls can't seem to kill it.

Ok, seems it's Sea Breeze beach aster. I've been meaning to find out as I found a bit growing out of some concrete when I went to collect my car after a service and stuck it in the garden where it very quickly took over a large area. Should have guessed really as the garage is right next to the beach!