There are different kinds of chicory. My types are more properly called curly endive and escarole, and I use them for salad greens, although they can be sauteed and used in soups. A couple of years ago in early spring I bought what I thought were dandelion greens
and forgot about them in the refrigerator. The bunch began sprouting roots, so I whacked off most of the green top and planted it in the garden to see if it would grow. Well, it did and it's the gift that keeps giving, so to speak. I let it flower (it was blue so a broad leaf chicory) and then go to seed. It happily reseeds in my garden and I've also thinned and transplanted it throughout the garden when I have open spots.
I am in MI and the chicory is pretty much a 3.5 season green if I mulch and use a floating row cover. Roots can be roasted and used as a coffee substitute or extender, and this might be more a case of wild chicory, I don't know. I've never done that but I do use chicory coffee
which I add to my regular brew; it gives it a darker, richer flavor. People do use the root medicinally, but I have no knowledge about that.
Some find the greens bitter--my husband won't eat it--but I don't find it any more bitter than other types of mesclun lettuces. I tend toward lower carb eating and I usu. have a huge salad for lunch that includes mixed greens (chicory, swiss chard, Red Russian kale, spinach, baby lettuce...whatever is in season), some berries, a protein (chicken, pork, beef, eggs), feta or bleu-type cheese, a handful of chopped nuts or sunflower seeds, and a home made olive oil-based vinaigrette.
Hope that helps...it really is easy to grow, and it's tasty and nutritious :-)