Distorted Carrots?

OK - so I move to a new house with a massive 150ft garden. Now I don't know a lot about gardening, but I decided it would be worth a try growing vegetables. I got a good crop of potatoes, especially since they were grown from peelings. Peas and beans were great. My sweetcorn, squash, celery, courgettes (zucchini) are delicious. The tomatoes - well, I'm getting sick of them! The cabbage and broccoli are fine now that I've persuaded the caterpillars to go elsewhere.

My carrots though are pathetic. They grow, but I've never seen such distorted efforts.
Now there must be some knowlegeable gardeners out there. What am I doing wrong?
Does Miracle Grow contain testosterone?