Carrots (Daucus carota var. sativus) are cold-hardy biennials that thrive in U.S. Department of Agriculture plant hardiness zones 4 through 10. Though carrots will survive winters in the coldest zones and live to flower and go to seed the following year, they're grown as annuals in most gardens. From seed to harvest, it takes 50 to 80 days to grow a carrot to maturity. You can begin harvesting baby carrots in 30 days when they're at least the width of your pinkie.
From seed to harvest, carrots mature in 50 to 80 days. You can harvest baby carrots approximately 30 days after planting seeds.
About Carrots: East and West
Carrots are loosely grouped into "eastern" and "western" types. The "eastern" cultivars are often purple or yellow, similar to the carrots originally domesticated in Persia (now known as Iran). The familiar orange carrots developed in the Netherlands approximately 500 years ago are the "western" cultivars.
In addition to the purple, yellow and orange carrots, there are red carrots, which contain more lycopene (an anti-oxidant plant nutrient), and mild, sweet, white carrots. Carrots can be long and slender, short and stubby or round like radishes.
Plant the Garden Bed
In spring or early summer, put on your garden gloves, safety goggles and closed-toe shoes before you till the garden bed and remove plant debris, sticks and rocks. Dig in 2 to 4 inches of well-decomposed compost or commercially prepared garden soil to a depth of 12 inches. Soak the carrot seeds for several hours or overnight in warm water. Plant 1/4 to 1/2 inch deep and 1 inch apart in rows spaced 12 to 24 inches apart.
Lightly cover the seeds with moist soil, peat moss or vermiculite. Keep it moist until the seeds germinate in 14 to 21 days. While carrots will germinate in temperatures as low as 45 degrees Fahrenheit, cooler temperatures slow germination.
In colder climates, protect your carrots from late-spring freezes by covering them with a thick layer of straw mulch. Where winter climates are mild, plant the carrots in fall for the winter garden. Carrots grow best in temperatures of 60 to 65 degrees.
Grow Carrots in Pots
When the soil is poor, rocky or boggy, consider growing carrots in containers or raised beds. The 2- to 4-inch-long Daucus carota 'Little Finger,' 5- to 6-inch-long Daucus carota 'Royal Chantenay' or round Daucus carota 'Round Romeo' and Daucus carota 'Thumbelina' cultivars are suited for containers. Use an organically rich potting soil and plant the seeds in circles in round flowerpots or rows in square or rectangular containers or raised beds. Monitor closely to ensure the potting mix doesn't dry out.
Care for Carrots
Thin the seedlings when they reach 2 inches tall, spacing the plants 2 inches apart. Snip off the tops with sterilized scissors; don't disturb the roots by pulling up the weaker seedlings. After 30 days, begin harvesting every other seedling to enjoy as baby carrots in the kitchen.
Remove weeds as soon as they appear so you don't disturb the carrots. Fertilize the carrot bed by side-dressing with compost midseason. Alternatively, apply a low-nitrogen 5-10-10 slow-release fertilizer approximately six weeks after planting. Always water after fertilizing.
Keep the soil evenly moist and mulch along the carrot rows, keeping the mulch 2 to 4 inches away from the carrot tops. When the carrot shoulders appear above the soil, brush a little mulch over them to prevent them from turning green and bitter. Harvest the carrots when they reach 3/4 to 1 inch in diameter about 50 to 80 days after planting.
Ruth de Jauregui is the author of 50 Fabulous Tomatoes for Your Garden. She writes numerous home and garden articles for a variety of online publications. She got her start as a book and cover designer in San Francisco for William (Bill) Yenne at American Graphic Systems. In addition to designing books, she wrote her first book, Ghost Towns. With several nonfiction books under her belt, de Jauregui recently published her first novel, Bitter.