@Shirageva and I offered to run a foarging trip along the Grand Union Canal in West London to demonstrate the wild larger which is on our doorstep. We picked several kilos of blackberries in one morning and produced 260 jars of jam for the Canal River Trust. An article with what we did and recipe can be found here – http://canalrivertrust.org.uk/news-and-views/features/towpaths-jam-packed-with-foraged-foods