Carrot Plant Care Guide: How to Successfully Grow Carrots

While carrots are common root vegetables and inexpensive to buy in stores, there are several great reasons to grow your own. One of those reasons is that seed catalogs offer purple, yellow, black, and multi-colored carrots in all shapes and sizes, a far cry from their pale and rather hairy central Asian carrot ancestors. Plus, while these close relatives of parsley and dill are slow-growing — about 120-180 days — when you finally unearth your carrots, the sweet, bold freshness is far superior to store-bought. These biennials also make great companion plants for tomatoes and peas. Learn how to grow carrots yourself with some simple care tips below.

How to Plant Carrots

Carrots take up little horizontal space in the garden in return for the harvest they provide. The only challenging aspect of planting carrots is their spacing and slow germination time.

Growing From Seed

Carrot seeds are small, slow to sprout, and hard to sow evenly. If too close together, they will have to be thinned to one and a half to four inches apart — the exact measurement will depend on the thickness of the carrot type. There are handheld seed dispensers that may help, and some seed companies offer seed tape that serves as a guide for perfect spacing. Here is another trick:

• Boil one tablespoon of corn starch in one cup of water for a minute.
• Let it cool to room temperature, and then pour the gelatinous liquid into a zipper-top bag. Mix in the seeds.
• Where you have prepared your soil, make a quarter-inch furrow. Then snip off a corner of the bag to make a very small opening and squeeze the gel and seeds in a line as if you were caulking the bathtub. This spaces them out nicely and keeps them moist until they germinate.
• Cover lightly with soil, and don’t water right away; the gel will take care of keeping seeds moist for a couple of days. 

Some gardeners cover the row of carrots with a plank for several days to keep moisture in, since the tiny seeds can’t be planted too deeply and so risk drying out. The plank must be removed as soon as germination starts in seven to 21 days. A light mulch can also be used to keep moisture in.

Carrot Plant Care

Carrots require well-prepared soil and regular irrigation, but once started, they are hardy and usually fuss-free.

Light

Carrots require full sun but can tolerate a bit of light shade.

Soil and Nutrients

Carrots require well-drained, friable soil, free of heavy lumps and rocks that will cause carrots to be misshapen, stunted, or intertwined. Prepare your planting area with plenty of organic matter, and consider the depth your carrots will need. The National Gardening Association suggests sprinkling a thin layer of wood ashes over the seedbed after tilling; this adds potassium to the soil and produces sweet carrots. They also suggest adding amendments to adjust for any nutrient deficiencies. Just make sure your soil does not have too much nitrogen, as it will cause root branching.

Water

Before germination, seeds must be kept moist by watering them daily and/or keeping them covered. Once sprouted, the amount and frequency of irrigation depend on how quickly moisture evaporates, and this depends on your soil type as well as the weather. Use a moisture meter to make sure carrots are deeply watered.

Temperature and Humidity

Though tolerant of light frost, carrots are temperature sensitive. Certain varietals reach peak flavor in cool weather and some in hot weather. A study at the Kindai University in Japan found that when hydroponically grown carrots’ temperature was in the mid 80s, certain nutrients were more readily absorbed by the plant as it responded to the stress, but the overall size and well-being of the plants decreased. Plants in soil that is too cold will struggle as well, but carrots in temperatures between 60 and 70 degrees F gain good growth for the root.

For moderating temperature, spread mulch or compost around the carrots once they have sprouted. This will also keep soil from making a dry crust or leaving the root tops exposed.

Common Pests and Diseases

The carrot fly is a widespread pest that can damage carrots, turning the leaves rust-colored then yellow. The fly’s underground larvae munch the outside of the root, making tunnels and rendering the root unmarketable and inedible. Since ground-dwelling beetles and spiders eat the larvae, you'll want to make sure they can thrive in your garden. A study carried out in Poland found that interplanting with dill or Welsh onion reduced damage from the carrot fly and increased yields, though the onion was less competitive with the carrot for nutrients and light.

How to Harvest Carrots

Carrots can be kept in the ground until needed, even through a light frost. Before pulling them up, soak the soil to help loosen them. Holding the stems close to the crown of the root, twist as you pull straight up. Store them in a cool place as soon as possible.

Carrot Varieties

Aside from color and shape, the length of the growing season, the time when their flavor peaks, and the depth of soil are all important considerations for choosing your carrot varietal. Since some types of carrot prefer cool, fall weather (until the ground freezes) while others taste best in summer heat, it’s possible to grow one kind or another during most of the year.

• Chantenay carrots are broad at the top, chunky, and short, tapering down to a point. These short varieties tolerate clay soil better than long, tapered carrots.
• Round varietals like Paris Market and short types like Amsterdam grow well in short seasons and in less-than-ideal soil conditions.
• Long and slender types for deep soil include Danvers and Imperator.
• Nantes are medium-sized, cylindrical with a blunt end.
• Multi-colored carrots can be found in heirloom seed catalogs, which offer a rainbow of carrots with great names, such as Dragon, Atomic Red, Black Nebula, Cosmic Purple, or Solar Yellow.

How to Store and Preserve Carrots

For best results, fresh carrots can be stored for several weeks at 33-39 degrees F and relatively high humidity. They can also be placed in a bin or bucket covered with moist sand and kept in a cool place such as a cellar. Carrots can be sliced, blanched, and frozen; pickled; or even dried in a dehydrator to become part of a homemade instant soup.