Is my soil wrong for carrots?

[Lämmchen]

For the first time last year I planted a vegetable garden using the existing space the previous owners had used. They eventually turned the garden into a sunflower garden because there was too much work involved in maintaining a vegetable garden.

I planted some carrots along with some other vegetable and my carrots really didn't grow very well into the ground. Does this happen often? They stayed thin and short and eventually rotted or mutated into something strange looking. Any advice?