Carrots are among the easiest vegetables to grow as they can withstand a variety of temperatures, from a light frost to summer heat. In addition, they are relatively fast-growing, and all parts of the carrot are edible, making them one of the most efficient vegetables.
There are several different types of carrots, including:
Chantenay – often the most ideal for clay-heavy soil or for shallow containers as it is shorter and wider, and therefore less likely to be affected by shallow soil
Nantes – a fast-growing variety that is among the best late-season carrot varieties as it can often withstand frost, even when mature
Danvers – your typical wedge-shaped carrot with a pointy tip
Imperator – a sweeter variety of carrot and, as such, is probably the most commonly grown carrot. It is also the longest and narrowest variety of carrot.
Carrots should be direct-seeded in your garden as they don’t transplant very well. Look for a mostly sunny place in your garden. Carrots will grow in part shade, but the taproots will grow larger with more sunlight.
You can plant carrots as early as three weeks before the last frost date. They will be slow to germinate when the soil temperature is cool, but this will give you a head start on planting. Once planted, it’s essential to keep the carrot seeds moist until they germinate. Consider placing burlap or row cover over the newly planted seeds to retain moisture and reduce the amount of cold air hitting the soil. Remove the row cover once most seeds have germinated.
Before planting, be sure to add nutrients to the soil via compost. Carrots are a medium-feeder, so mix 1” of compost into the garden soil before planting.
To further maximize the size of the carrot, plant the seeds into smooth, friable soil. The size of the taproot a few weeks after germination will drive the size of the eventual harvest, so be sure to cultivate the top 10-12” of your garden soil and remove any large aggregates before planting the carrot seeds. In addition, any rocks or aggregates in the soil may cause the carrots to become forked or deformed.
Plant your carrot seeds with 1-2” spacing within rows that are at least 12” apart. Once planted, carrot seeds tend to be immature, so they need to be managed closely after planting. Specifically, make sure that the topsoil remains damp for the first few weeks after planting. We recommend draping row cover or burlap on top of the soil after planting to reduce water loss through evaporation. Remove this cover once most seeds have germinated.
Water the soil regularly as carrots prefer slightly damp soil, but don’t let the soil get too soggy or you may get root rot. As the carrot plants begin to mature (usually halfway to maturity – approximately 30-40 days after planting), add a little bit of extra phosphorus-rich fertilizer to help size up the carrot roots.
When growing the Nantes variety, mound a little bit of soil on top of the shoulders of the carrot (i.e., the top of the carrot root) to prevent these from turning green.
Pests and Diseases
Carrots are susceptible to pests such as carrot rust fly, nematodes, and root rot. To reduce the likelihood of infestation by the rust fly, grow your carrots beneath row cover and rotate your crops each year. Avoid nematodes by planting in early spring, as you’ll harvest the carrots before the nematodes become active. Summer plantings (for harvest in the fall) are more susceptible to nematodes, and crop rotation is the key to avoiding this pest. Finally, root rot is best prevented through crop rotation and planting the carrots into well-draining soil.
In addition to the above, gardeners also have to deal with four-legged animals when growing carrots. Rabbits love to eat the leaves of young carrot plants, while mice and voles will enjoy the tops of the carrot roots when they are fully ripe. The easiest way to prevent them from eating your harvest is by hiding your carrots behind a row of onions, which most rodents avoid, or by placing a cage over top of the carrot bed.
Harvest your carrots when the shoulders reach an adequate size – the shoulders are the visible portion of the taproot. The Chantenay variety of carrots should be harvested on a timely basis before it becomes woody. Other varieties, such as Nantes, can be left in the ground as a form of outdoor storage in the fall if there are no active pests around the carrots. Remove the carrot greens as soon as you harvest them (the greens are edible) and store the roots in a cool, damp place for two weeks.