Invasive

Himalayan Balsam, related to Busy Lizzie. An Asian annual plant which has spread across most of Europe.
From a single seed it can grow up to 2.5 metres in one season. It takes over large areas, especially river banks, and suffocates many of our smaller wild plants. Huge efforts are being made to control it but it is probably here for good along with Japanese Knott weed which can force its way up through tarmac paths and New Zealand Pygmy weed which can completely cover ponds and waterways.