 Typically, most carrots take about three months to grow from seed to finish. There are cultivars that take up to 120 days. And what I love about carrots are they're really good for you. In fact, one carrot contains alpha and beta carotene, which is a good source of vitamin K, as well as vitamin B6. Carrot cultivars are grouped into two broad classes. One is called Eastern carrots and one are called Western carrots.