The tall, pretty pink flower spikes of rosebay willowherb, a useful nectar source for pollinators, are a common sight on railway banks and disturbed woodland in the UK. In a wild cottage garden it is truly impressive, and is able to compete easily with other vigorous specimens, spreading by seed and rhizomes. But in the more restrained environment of a neatly manicured garden its vigour makes it likely to try to take over, so care must be taken situating this plant.
For best results, sow immediately onto a good soil-based compost. Cover the seeds with fine grit or compost to approximately their own depth. They can be sown at any time, and germination can sometimes be quicker if kept at 15 to 20 degrees C. We sow most seeds in an unheated greenhouse and wait for natural germination, as many seeds have built-in dormancy mechanisms, often waiting for natural spring germination, hence giving them a full season of growth.
Common name:Rosebay Willowherb, Chamaenerion angustifolium, Fireweed