Everything you need to know about growing carrots
Find a video version of this growing guide on my YouTube channel HERE.
Carrots are easy to grow once you understand their specific requirements to germinate and grow properly. They are ready for harvest in about 4 months from seed.
Cultivar Selection
⦁ Color - colors range from orange, white, yellow, purple, and black.
⦁ Flavor - To be honest they all taste pretty much the same. The darker color cultivars tend to be a little more savory.
⦁ "Imperator" - carrots that produce long roots. Needs very loose and deep soil.
⦁ "Danvers" - medium length carrots. This type does better in compact/hard soils.
⦁ "Nantes" - Carrots are almost coreless which is great for juicing. They are the same diameter from top to end of the root.
⦁ "Chantenay" - The best cultivar for rocky and heavy soils. Roots are more stocky.
⦁ Heat tolerance - there are some varieties that tolerate more heat than others, which is what I grow exclusively.
⦁ My personal favorites - Danvers and Japanese types - just very reliable, nice uniform sizes
When to Sow Seeds
⦁ Direct Sowing ONLY - Root crops will send down a large tap root that must not be disturbed.
⦁ When to sow - general guidelines are to sow seeds about 2 to 3 weeks before the last spring frost date at soil temperatures between 40F-75F. Check out www.plantmaps.com to get an idea of your average last spring frost date.
⦁ This doesn't apply to warmer zones like +8 - carrots need 4-5 months of a growing period in the coolest part of the year. For zones +8 that is fall, winter, and spring. If it is too hot, they get stunted and don't grow.
⦁ If your in a warm zone - follow growing during its ideal temperatures AND grow the heat tolerant cultivars for better success. Ideal temperatures is between 40F to 80F. Using my garden in zone 9B as an example, www.plantmaps.com shows that my monthly average max temperatures is below 80F during the months of November thru March. Therefore, I direct sow seeds in November and usually harvest by February. Some of the more heat tolerant cultivars, like the black carrots or Manpukuji, can be started earlier in September. December is the last month I will direct sow to make sure I harvest before March.
Sun & Soil Requirements
⦁ Sunlight - Pick a spot that has +8 or more direct sunlight. This is going to be North to South orientation.
⦁ They need loose soil - sandy soil is great if its loose. Can mix in some peat moss to loosen it up. Or grow in a raised bed or deep containers filled with very loose potting mix.
⦁ I recommend garden beds/containers that are at least 8-10 inches deep for regular carrot cultivars. If it is an extra long type, like Manpukuji, they need 24 inches or more.
How to Direct Sow Carrot Seeds
⦁ A good trick to ensure that you get a nice straight row of carrots, is to use a stick or broom handle to push an indent into the soil. This gives you a little indent in the earth in which to place the seeds. Sprinkle seeds over the soil surface, press down, barely cover with soil.
⦁ KEEP THEM MOIST or they wont sprout. I water the area daily. If you cant manage that, place a board over them to lock in moisture. Check on them daily and as soon as you see good germination, remove the board because they now need sunlight
⦁ Thin seedlings out once they are 1 inch tall. Remove/thin out seedlings to about 4 inches apart to allow each root the space it needs to grow in size.
***Extra tip*** You can direct sow radishes seeds along with the carrots. Radishes germinate quickly, which helps mark where the carrots have been sowed. The radishes are harvested in 30 days which frees up the space for the carrots to continue growing in.
Now that they are growing
⦁ Water Requirements - Carrots need at least 1 inch of water per week. Soak the soil thoroughly when watering. Carrots grown in dry soil may become misshapen, crack, or develop a bitter taste. Since I grow carrots over fall, winter, and spring here in FL, this is also our dry time of the year so monitor the carrots closely.
⦁ Growth Habit - They get bushy, the more leaves the better. Leaves = more energy production = bigger roots. Do not prune leaves unless its diseased.
⦁ Fertilizing - Good application of something high in nitrogen (blood meal) at the beginning is essential to promote a lot of rapid leafy growth. ONLY initially. Then half way thru the growing period, switch to fertilizers higher in potassium & phosphorus which encourages large root formation.
Pests
⦁ Nematodes - microscopic worms that attack the roots cutting the plant off from water and nutrients. They especially love warm, wet, sandy soils. Add organic material into your soil. Rotate crops. Do not plant nematode sensitive crops in the same spot year after year. If needed, solarize during the summer with a clear plastic tarp. Add crab meal to the soil. Grow lots of marigolds and use them in your compost or "chop and drop" marigolds into your soil.
⦁ Carrot rust fly larvae and root maggots - The fly is not the problem, its their larvae that eat into the root. Use row covers or yellow sticky fly traps.
⦁ Worms - the leaves will look munched on or you will find small orange/green/black balls on the leaves (worm eggs and poop). You probably wont find the worms because they tend to be nocturnal. Spray with BT (bacillus thurigensis) or Spinosad. Both are considered organic.
⦁ Thrips are tiny yellow insects with wings. They suck the juices out of plants. Setup blue sticky traps, use row covers, spray with neem oil or other strong smelling essential oils, attract beneficial insects that eat them, plant trap crops like nasturtiums.
Diseases
⦁ Rotting roots - Moist conditions are usually the cause. Grow in containers or raised beds for better drainage. Do not water until the soil has completely dried out.
⦁ Leaf diseases - mildew, blight, yellowing spots. I treat all leaf diseases with 1 cup of hydrogen peroxide (3%) per gallon of water.
Harvest
You want to find the sweet spot where the roots get as big as possible but before they get woody in texture and/or warmer weather arrives. This will vary per cultivar.
⦁ Most seed packets will say ready for harvest in 90 days. I think that is not realistic. I recommend to harvest at the 4 month mark to make sure you are harvesting large carrots.
⦁ In my experience, when I harvest around the 3 month mark, they are still too small and have a weird taste. Carrots taste bitter or soapy because they contain terpenoids. Carrots harvested early have not had a chance to develop its sugar content to counter act the terpenoids.
⦁ Test one carrot at the 4 month mark and decide if it is ready before harvesting all of them.
⦁ If your ground freezes, harvest the carrots soon after the first frost or protect them with a deep layer of mulch or straw.
⦁ If hot weather is expected, it is best to harvest all of them since heat causes them to taste bitter.
⦁ Harvest in the evening when the carrots have the highest concentration of sugar.
Storage After Harvest
⦁ 2-4 week storage in the fridge - Wash the roots and cut off the leafy greens. Place in a bag with a piece of paper towel to absorb excess moisture. Allow them to dry before storing in the bag.
⦁ Can process the harvest by freezing, canning, or pickling.
⦁ Can leave them in the ground until you are ready to use them if your in a colder climate. Make sure you cover them with straw or mulch if a hard freeze is expected. Harvest all of the carrots before spring arrives. Eat them spoon after harvesting as they wont last very long.
⦁ 6 month storage in a root cellar - store in a cool, dark place where the temperature is 32°-38°F. Do not wash the carrots. Brush off the extra soil and let them dry for a few days. Pack them standing upright in a box or container with sand, sawdust, or mulch for insulation.