I planted woad from seed last year intending to use it to dye cotton fabric which I would later turn into paper. I had not read the full instructions on the process before I purchased and sowed the seeds. It is a complex process to create a blue dye from the leaves, therefore I did not attempt it last summer. According to the book, Wild Colour, the leaves will produce pink or tan color when processed the usual way other plants are to extract color. The seeds will produce a third set of color: mauve, grayish green, grey.
Traditional advice regarding the cultivation of woad is to dig it up in the fall after the first year of planting or leave it if you want to save some seeds the following year. It is recommended to get rid of it after it has served its purpose - that is producing leaves in the first year for a blue dye. The reason for this is if allowed to go to seed, it will become a pervasive weed. (Having mustards and Dame's Rocket sprouting up all over each year, I can believe this!)
I allowed the plants to stay, thinking I might try the seeds as a dye. I'm so glad I kept them! They quickly began growing in early spring (being a brassica, it loves cool weather). About two weeks ago flower buds appeared and now has been in bloom for a week. The cloud of chartreuse flowers is gorgeous! Standing close, you can smell its delightful faint fragrance.
Being a brassica, it is a good pollinator plant, attractive to an assortment of bees and butterflies as well as a host plant for the larva of cabbage whites.
