Hedgerows (to me) are people's property, parks are the property of someone or organisation, all land in GB is owned by someone - even commons are not common to everybody, so how and where in this land does anyone 'forage for free'?
it is an interesting question.
as i say im ok with foraging from country lanes - road side. technically its someones hedge but i dont see it being a problem.
you dont need to buy foreign apples though. i know lots of folk giving away apples right now - several houses in my village have a box outside their doors with a 'please help yourself' sign - and there are pleas for people to come and pick via freecycle etc. perhaps you should ask on freecycle?