For me, two very different things come to mind when I think of carrots (Daucus carota ssp. sativus): Good eyesight and Beatrix Potter’s Peter Rabbit! While these might be significant in a cultural sense, they admittedly have very little to do with the actual carrot plant.
Carrots are root vegetables that use a thick taproot to store energy for future flower and seed development. In the home garden, though, it’s rare to see these plants complete a full life cycle.
In this article, I’ll walk you through the various carrot growth stages and explain how we take advantage of its natural life cycle to cultivate a delicious, nutritious vegetable crop.
Conditions for Growing Carrots
Carrots grow well in USDA zones 3 to 10. They are cool-season vegetables that grow best in the spring and fall. In cooler climates, however, they may be grown and harvested in the summer as well.
Since the main prize of a carrot plant is the large taproot, soil conditions are crucial to producing a good harvest. Carrots perform best in very loose, sandy soil that doesn’t restrict root development.
Raised beds are an ideal growing environment for carrots because they offer the flexibility of easily amending or completely replacing the native soil with something more suitable. For most carrot varieties, I recommend using raised beds with a depth of at least 12 inches.
You can also successfully grow carrots in individual pots. Again, containers should be at least 12 inches deep and just as wide to allow for root growth.
While most of the action takes place below the surface, carrots still need plenty of sunlight. An average of 6 to 10 hours of direct light per day is recommended for optimal growth.
Irrigate with 1 inch of water per week throughout the growing season. The soil should drain quickly and never be allowed to turn soggy.
Traditional nitrogen-rich fertilizers will encourage carrots to develop more top growth versus focusing on root development. In addition to amending the bed with compost before planting, I personally recommend a no- or low-nitrogen formula with an NPK ratio similar to 0-10-10 or 5-15-15 throughout the growing season.
Be careful when weeding, mulching, or fertilizing around carrots. The taproots can be very delicate, especially early in the plant’s life cycle, and disturbing the soil could damage the crop.
Carrot Plant Growth Timeline – Timelapse Video
Growth Stages Of Carrot
According to South Dakota State University, carrots require on average 55 to 80 days from planting to harvest. The main factors that will affect this time frame are the type of carrot grown and general growing conditions.
You can technically harvest carrots at almost any time during the growing season. But carrots pulled before the above maturation period has ended will have low-quality flavor and texture.
Garden carrots are broadly grouped into 4 categories based on size and shape. These include:
- Danvers — Long, thin, and tapered; classic carrot appearance.
- Nantes — Same thickness throughout with rounded ends; the best option for heavy soils.
- Chantenay — Long, smooth, and tapered; thicker than Danvers carrots.
- Imperator — Short, stout, and slightly tapered; well-suited to more compacted soils.
Out of these different carrots, Nantes is the fastest-growing, with many cultivars maturing in as little as 65 to 75 days.
While carrots are harvested in their first year, these plants are actually biennials. Biennials take two years to complete their life cycle. For carrots, the first year is focused on storing energy within the edible taproot. In the second year, this energy is then utilized to send out a flower stalk and reproduce.
1. Seed Germination
Every carrot starts as a small, brown seed. If you’re wondering where those seeds come from, remember that the edible part of a carrot is a root (there are no seeds hidden inside!). The seeds of a carrot plant are instead produced in the second year from a tall flower stalk.
Carrot seeds will germinate as long as the soil temperature is at or above 45°F. Optimal germination occurs when the soil temperature is warmer, up to 80°F.
Because carrots require cooler temperatures to sprout than other garden veggies, germination also tends to take a bit longer. You should expect viable seeds to germinate in 14 to 21 days at an appropriate temperature.
Moisture and soil temperature work together to trigger seed germination. The first structure to emerge from the seed is the radicle.
The radicle is the primary root of a plant seed. In carrots and many other species, this root will eventually develop into the main taproot.
As the radicle anchors itself into the surrounding soil, an embryonic stem and two cotyledons will also emerge from the seed. These structures will grow upward and break through the soil, transforming the germinated seed into a young seedling.
Carrots are dicots, which means that each seedling has two cotyledons. Cotyledons are simple, embryonic leaves that develop inside the seed itself.
Carrot cotyledons are relatively long and very thin. The cotyledons provide valuable energy while the seedling waits for its first ‘true’ leaves to grow. The very first ‘true’ leaf typically appears between the cotyledons after 2 to 7 days.
Unlike the cotyledons, this new foliage will look like a miniature version of a mature carrot leaf. It’s normal for the cotyledons to fall off at this point since the seedling no longer needs them.
3. Vegetative Growth
Mature carrot leaves are soft and frilly. The leaves emerge in a rosette shape from the base of the plant.
According to Pennsylvania State University, most carrots have 8 to 12 leaves. The overall size and growth rate of the leaves varies between the different carrot types — for example, Imperator carrots produce extremely vigorous top growth.
4. Root Development
At the same time as the plant is putting out new, larger foliage, the taproot is developing below the soil’s surface.
The taproot — which started as the seed radicle — will gradually lengthen and thicken throughout the growing season. It will start to resemble a very thin carrot after about 30 to 45 days.
Of course, the main taproot is not the only root of a carrot plant. Shortly after the taproot begins growing, it will develop secondary roots that reach out into the soil. These secondary roots are usually white, thin, and fibrous.
If a carrot plant is left to overwinter after its first year, it will produce a flower stalk the following spring. The stalk will develop an umbel-type flower in early summer.
A single umbel flower is made up of dozens of white inflorescences that look a bit like lace. Each inflorescence is capable of turning into a seed after being pollinated by the wind or insects.
Carrots are self-fertile, so inflorescences within a single umbel can pollinate each other.
When To Harvest Carrots
The best indicator that a carrot is ready to harvest is the number of days that have passed since planting. As your carrots near their expected harvest time, you can brush away the soil around the crown to double-check the taproot’s size.
For more life cycle articles, here’s a link to Growth Stages of the Potato Plant that you may also find helpful.
FAQ Carrot Plant Stages
- South Dakota State University Average days to harvest of carrot
- Pennsylvania State University Foliage of a carrot
Ben's horticultural interest grew when graduating from Hertfordshire University in 1997. Having contributed to numerous publications including Better Homes & Gardens, Garden Design Magazine, and The English Garden. He is also the author of Propagating Houseplants Made Easy.