Edible? Every day’s a school day
“After flowering between June and October, the plant forms seed pods 2 to 3 cm (3⁄4 to 1+1⁄4 in) long and 8 mm broad (1⁄4 in), which explode when disturbed,[6] scattering the seeds up to 7 metres (23 feet).
The green seed pods, seeds, young leaves and shoots are all edible. The flowers can be turned into a jam or parfait.[7]”
The best way to collect the seeds from ripe pods is to carefully put a large bag over the top then hold it closed below the pods, then squeeze the bag, you’ll feel the pods explode. One problem is that the plant often grows along river banks, so getting to it can be problematic.
It’s easier to control than many invasive plants, just hacking the plants down or digging them up before they flower, or at least before the pods ripen – it’s the fact they can send the seeds so far that’s the main issue, plus the seeds float downstream and spread even further that way.
Good on salads, apparently, there are recipes around for using Himalayan Balsam.