Echium pininana, aka Tower of Jewels, Giant Viper’s Bugloss, Tree Echium, and Echium pinnifolium.
These are tropical plants but they can survive in London if the winter’s not too cold. They are biannuals, which means they grow in one season and then flower in their second. After flowering the plant dies back, but happily, if in a suitable spot, echium readily self-seed, and can also be raised in seed beds.
Once mature echium plants grow exceptionally tall and develop a huge flower spear that is covered in pale purple or blue blossoms. Think a butterfly bush on steroids, reaching for the sky. Sure to be an eye-catcher, the flowering plant is also favoured by butterflies, bees and other essential pollinators.
We’ve planted one into the back patch meadow area and have high hopes for its development.