On 30 May 2025, the previously reported invasive Himalayan Balsam (Impatiens glandulifera) plant was confirmed to be growing near the lower Greenside boundary of the hill. A group of volunteers removed a few hundred plants, mainly small ones, on 13 June.
Please tell us if you see any of it in other areas! As always a W3W (What3Words) reference is really useful. We want to keep Calton Hill clear of invasive species.