First, look at your seed package to see how many days it takes your chosen variety of carrots to mature.Baby carrots are usually ready to harvest 50 to 60 days from the planting date. Mature carrots need a few more weeks and are usually ready in about 75 days. Most carrots are ready to harvest when the shoulders are 1/2 to 3/4 inch in diameter, but again, there is much variation depending on the variety.
To harvest loosen the soil with a garden fork before harvesting carrots. Cut off the green tops 1/4 to 1/2 inch from the top of the carrot and rinse and dry the roots before storage.