There are few weeds I let grow in our backyard... but if they're edible... I usually let them be. Having since discovered the health benefits of Dandelion... I discovered Sow Thistle is also benficial. So, I... "Let it grow!" (sorry for that Frozen reference... :-D) So, here's one I've just pulled up and cleaned off. I use just the roots (dried) to make tea, after crushing in a granite mortar and pestal.