Linda0818
Head Chef
I grew some coriander one year. It did well in terms of seed production after it bolted. I had volunteer coriander the following year. Since I don't like cilantro, we didn't use the leaves.
I have volunteer (tons of it) spring onions every summer. And that's from ONE year, about 12 years ago, of tossing a packet of spring onion seeds into the bed under the kitchen window. Didn't plant them, just tossed them. And they've been coming up every spring ever since.
Funny thing is, I rarely use them for anything. Maybe all summer I'll go out and pick some 3 or 4 times and that's it.