Why are the tops (and sometimes inside the stem) of my mature garden carrots green?

Question

Why are the tops (and sometimes inside the stem) of my mature garden carrots green?

Answer 1

If the tops of the carrots were sticking up above the soil then they will start producing chlorophyll. It's normal if a bit bitter tasting. To keep this from happening you can bank soil up around the exposed part of the root as they grow.

Answer 2

It is green because the top is sticking up above the soil( or close)  Keep the actual carrot covered with soil well but of course let the leaves out to the sun