Fantastic as a short-term foliage accent in a big bed, border, or herb garden, milk thistle (Silybum marianum) forms big, bold rosettes of spiny leaves with silvery white veining in its first year. In the second summer, each rosette sends up 3- to 6-foot-tall stems topped with spiny heads of pinkish purple flowers. It is likely to self-sow if you don’t remove the flowers before they form seed. (The flowers aren’t that great, so you may just want to dig out the foliage rosette at the end of the first season unless you really want to harvest the seeds.) Be aware that this species is considered invasive in some parts of the country. Please check its status in your area before buying the seeds: Invasive Plants Atlas map for Silybum marianum.
Full sun. Biennial; Zones 5 to 10.
Collected in 2019 for the 2020 growing season. At least 15 seeds.