Hi everyone, my name is Ali and I bounce between London and Amsterdam. In the UK, most of the land is private land. Therefore, foraging is usually only allowed if you have permission from the landowner.
As for whether foraging is popular, I am not sure, at least not in my friend circles and people I am familiar with. Sometimes people I know or am out with might pick a flower or a plant casually, but not necessarily as a hobby.
I do live next to a Wetland, and I just discovered that there is an association that manages it. I try not to interfere however with the wildlife or plantation, as the wetland is quite new, and there appears to be a very deliberate effort on behalf of the council and local volunteers to ensure that the ecosystem is a certain way.
Looking forward to learning more about this practice!