Sorrel is a perennial. Completely different than lettuce and spinach which are annuals. Once lettuce and spinach bolt, they get bitter and die after they produce seeds (if you let them). That's just their nature. They won't come back unless you let them self seed (self sow?).

Rodney

Ah, I didn't realize that. So when those bolt pull 'em.

Good to know about the sorrel. I'll just leave them as a border plant.

What about Chard and Kale? Do those keep coming back or bolt and die?

Same thing with kale and chard. Once bolted, they're done. But, I've yet to see a kale plant bolt and both are good for a year or 2 as long as you keep the root zones somewhat cool. Mulching heavily really helps.

Kevin

Good info.

Thanks guys.

Chard and kale are biennial. So technically, they will overwinter for one winter.
You could always seed seeds of cold-hardy greens (any, including spinach) in early fall for a spring harvest.

In some climates chard and kale will persist another year or so if you cut off the flowering stems but they become rangy and scruffy. Both self sow in climates with mildish winters.

Do not harvest sorrel leaves that grow in the very hot summer months - they collects to much of oxalic acid in hot weather and it is not good for your kidney. I usually pick leaves till June, then let them grow and bolt. In August I cut all the leaves to the ground, fertilize, and let it grow again. Now it can be picked till frost.

Also, be careful with sorrel, it tends to reproduce with reckless abandon. I believe it is in the mint family...

Sorrel is in the Polygonaceae, so not the same family as mint (Lamiaceae.)

gallinis, thanks for the tip. Every year I wonder if it's ok to use the new leaves that grow late in the season.

"Same thing with kale and chard. Once bolted, they're done. "

Not so, for sure, IME. I have had chard plants go 3-4 years in well-protected locations. Kale plants are well known to produce for longer than that in greenhouses or very mild climates, though I have not had one go for more than about 3 years.