Carrots take awhile to mature. They say 75 days average. I started some seeds September 1st and they still are not ready. I think in about 2 more weeks they will be a nice size. If I pulled them now they'd be small. I have pulled 2 of them so far one was regular size and nice. The other was on the small size. But both tasted so good. The carrots you grow are way better than the store kind.
Radishes grow really fast. well, Most of them do, some varieties take longer. Beets are another good winter crop, they take about 60 days. I have pulled one up so far, the other are still a little too small. The good thing about these roots crops is you can kinda tell when they are ready cause part of their root/bulb pops out from the soil so you can see the size. Another way to check is gently wipe away some dirt by the bulb and take a peek at it. If it is too small cover it back up. Cilantro, parsley, dill, lettuce, green onions and leeks all grow good now too. I am growing all this right now.