Flowering Carrots?

First time gardener mistake, letting fruits and vegetables grow for too long.  Over the weekend my carrots grew a foot and flowered. Pretty, but I think I was supposed to pick them before this. Clearly I'm still learning. I found this article by Lisa Green from the Examiner.com for future reference on when to harvest carrots, thanks Lisa!

Have you ever made a gardening mistake? Please feel free to share any tips to help others prevent future garden mishaps.