My wild food friend Steph reckons they’re inedible, but they are in the books and I think they are quite spinich-y and even palatable raw. The young tips of Rose Bay Willowherb, can be peeled and cooked like aspasgus and eaten with butter.
Also called Fireweed, its an immigrant from Canada, it can be found on wasteland everywhere, buut you need to catch it young now, before it starts to form flowers.
They are creeping around the edge of my allotment and I spotted them this morning, so they are ripe for picking. Try them and see which side of the fence you come down on!