Red claw crabs food

[Red_claw]

Hi all, I’ve read that red claw crabs will eat almost any leaves they get hold of. Does anyone know what leaves I could pick naturally (within the uk) that they can safely have? No probs with them taking spinach and kale but was thinking if I can pick a few leaves from trees and shrubs why not.
Thanks

 

[Sgooosh]

you can farm some lettuce
i have found that Butter Lettuce/buter head lettuce is easy to grow
you can also easily grow duckweed in a small container and crush up some leaves so they sink

 

[Red_claw]

Nice one thanks