With all the rain, these grew like crazy (and indeed, the darker-leaved one has already developed a bright mustard-yellow flower), so I harvested a few leaves as part of tonight's dinner. May I recommend? They had a particularly sharp, but not bitter mustardy bite. I'm looking forward to the seeds ... some I'm trusting will self-seed; others I'll cook with. I hadn't realized that it's actually a member of the Brassica family - like cabbage, or brussel sprouts: Brassica nigra, B. alba, B. juncea, and then B. kaber, or field mustard, which is what runs rampant all over Griffith Park (and then turns into a fire danger). I hadn't known. either, that a lot of Californian vineyard owners plant it as ground cover, and then plough it back into the soil because it releases lots of nitrogen. These plants are tasty, anyway, and apparently (famous last words) not generally vulnerable to pests.