Grand Mullein

Mullein leaves make a light gold silk dye.   Plants take 2 years to produce the yellow flowers on tall spikes which are attractively bright.  The fury leaves were used historically to make slow burning torches.

I annoy my allotment neighbours allowing Grand Mullein to grow (up to 7 feet). they are frightened of the hundreds of thousands of seeds dispersal.  I've been told the seeds are narcotic and dangerous to fish, so I havn't used them.