Carrots are a root vegetable that are not difficult to grow. Like other root vegetables they are a cool weather crop that grow best with air temperatures from 55-70 degrees.
Carrots are a high reward crop based on what it takes to grow carrots and what they yield in return. Many nutritional experts have raised the carrot into the superfood category because of the amount of vitamins, minerals, and antioxidants packed into each carrot.
Carrots are the taproot of the carrot plant. When we think of roots of a plant we usually think of a fibrous root system that has lots of branches going in all different direction. A taproot system is when a plant sends one major root straight down deep into the ground and side roots grow sideways off of the taproot.
Grow Sweeter Tasting Carrots
A carrot will get its flavor from the sugar content and the amount and type of terpenes in the carrot. Carrots develop terpenes that can give a carrot a piney, soapy, bitter, or spicy flavor. Terpenes also give a carrot its smell, piney, soapy, or floral are common aromas that terpenes give off.
For a carrot to develop a high sugar content the right temperature conditions during its last month of maturity is important. Highs during the days around 70 and lows at night around 50 make sweet carrots. The warm sunny days allow the carrot plant to make sugars and the cool nights allow the carrot to rest and not burn the sugars off.
Best Soil For Carrots
The best soil for carrots is similar to the best soil for most vegetables and that is loamy soil or sandy loam soil. Loamy soil is a mixture of 40% sand, 40% silt, and 20% clay. This mixture of different size particles allows air, water, and growing roots to pass through freely but will retain moisture and nutrients. A sandy loam soil is a soil that has more sand in it. If the soil is too sandy it will not hold water or nutrients.
The best way to improve the soil you already have it to add aged compost to it. To get access to large amounts of compost call your local city government and find out if the city has mulch piles. Many cities will collect grass clippings and leaves and put them into huge piles where you can get as much compost as you want.
Potting soil is nice because most come with all the fertilizer you need for the growing season already mixed in. If you’re looking for potting soil Miracle-Gro is a good standard soil and Organic Plant Magic is a reputable organic brand.
Best Fertilizer For Carrots
Fertilizer is labeled with three numbers N-P-K. These are the main nutrients plants need to grow and produce. The letters stand for the macronutrients that plants need, Nitrogen-Phosphorous-Potassium. There are three secondary nutrients plants need: magnesium, sulfur, and calcium, and then there are the micronutrients boron, chlorine, copper, iron, manganese, molybdenum, and zinc. This soil test will check for 13 nutrient levels.
Carrots are divided half into top growth and half into root growth. Nitrogen is mainly for above ground foliage growth, and potassium and phosphorous are for root and fruit growth. There is no fruit growth with carrots but the root growth is what we’re after and it takes potassium and phosphorous.
For carrots applying an all-purpose fertilizer at the beginning of their growth and then a fertilizer with a 1:2:2 ratio the rest of the season makes sense. Jack’s Classic is a great standard water soluble fertilizer that measures 20-20-20. Organic Plant Magic is my favorite. It measures 6-5-5 and has over 55 trace minerals and 13 different beneficial bacteria strains. Garden-Tone and Jobe’s Organics are other good organic brands.
Lilly Miller has a standard fertilizer with a 5-10-10.
Can Carrots Survive Frost
Carrot foliage can survive light frost from 28-32 degrees but will freeze and die off with a hard frost. Carrot growth below 50 degrees is slowed significantly so don’t count on much growth in a month with highs regularly below 50 degrees.
Carrots themselves can overwinter underground in a dormant stage until the spring comes. This is a mechanism plants that have biennial growing seasons have adopted. Even with air temperatures below 0 degrees carrot roots can survive underground especially with a layer of snow on the ground acting as insulation.
If you’re are proves troublesome to overwinter carrots you can add mulch or row covers to insulate and increase soil temperature. Clear row covers can increase soil temperatures up to 10 degrees whereas black coverings will raise soil temps around 5 degrees. The reason farmers use black row cover is that they don’t let sunlight in and so keep out the weeds.
How Often to Water Carrots
Water carrots with 1″ of water a week including rainfall. It’s best to water carrots and other garden plants with less frequent deeper waterings as oppose to more frequent shallow waterings. The reason for this is twofold.
- A deeper watering will go down 6-8 inches into the ground and force roots to grow deeper and more extensively to reach the water.
- Frequent shallow waterings leave the shallow roots of plants constantly drenched which can invite root rot and plant death.
Using a rain gauge or a rain barrel you have measured will give you an accurate reading of how much rain has fallen. Watering right after a light rain is usually a good idea.
To get an idea of whether or not to water reach down about 4 inches in the ground. If it’s moist let it be and if it feels dry water.
Do Carrots Need Full Sun
Carrots can grow in partial shade but do like full sun and should get about 6 hours of direct sunlight. Use mirrors, water, or glass sculptures to increase the sunlight in a garden.
Carrot Pests & Diseases
To organically control all foliage diseases and insect problems I reccomend regular neem oil and manual eradication. Neem oil is an organic substance made from seeds of a neem tree. Spraying neem oil on the leaves of vegetable plants covers them with a wax like coat that is not appetizing to insects and doesn’t allow disease like powdery mildew to come into direct contact with the leaves.
Neem oil also has a natural active ingredient, Azadirachtin, that will eat away at insect eggs and mature insects exoskeleton. When I get an insect infestation or foliage disease I’ll spray neem oil on the plants 2-3x a week. Manual eradication by walking through the plants and throwing bugs in a bucket of soapy water and squashing them is time consuming but effective. The combination of manual eradication and neem oil gets foliage disease and insect problems under control quickly.
Carrots are a root vegetable so soil bacteria and insects are also a major problem. As far as I know for most of these conditions the only thing to do is preventative actions. Move carrot crops around from year to year. Be sure to dig soil up once a year 8-12 inches down to let sun, warmth, and air to penetrate the soil.
For more specific information on carrot pests & diseases check out this article from University of Georgia Extension.