Observing the process of a seed grow into a vibrant, crunchy, and sweet orange vegetable is fun and rewarding. By learning the different stages the root vegetable goes through, you will become a better gardener. Each step is essential to the overall development of the plant.
Taking a close look at its life cycle provides insights into what the plant needs in each step of its development.
Days to Maturity
The amount of time it takes from planting a carrot until it are ready for harvest depends on the type you grow and, to some degree, your local climate. On average, they are ready to harvest in 75 to 80 days.
We typically grow carrots as annual crops, harvesting them when the fleshy tuber is ready to eat. However, in nature they (Daucus carota) are biennial plants, meaning it takes two full growing seasons from the time they germinate until plants fully mature and start producing seeds.
To give you a better understanding of how long it takes to grow these delicious orange vegetables, let’s break it down into the individual growth stages.
The first season in a its growth focuses on growing the tops and developing the tubers.
Carrots are a cool-season vegetable that needs cooler temperatures to germinate and grow compared to other plants in your vegetable garden. You can plant seeds in the early spring for a summer harvest or later in the growing season for a fall harvest.
Spring: Plant your seeds ahead of warm-season vegetables. Sow seeds 2-3 weeks before the last frost if using a floating row cover or after the frost threat has passed.
Fall: Wait until mid to late summer to plant, approximately ten weeks before the first typical autumn frost in your area.
After sowing your seeds, you can expect germination to take two to three weeks. Be patient — this is slightly longer than many other garden vegetables that sprout within ten to fourteen days and is due to colder soil temperatures.
Once planted, keep the soil moist at all times. Viable seeds contain an embryo and food reserves, wrapped up securely in a seed coat for protection. Moisture softens the seed coat in a process known as imbibition. The moisture then enters the seed triggering the internal cells to respire and metabolize the food reserves. Cell growth and elongation begins.
The first step in germination is the emergence of the primary root known as the radicle. Carrot roots anchor the plant in the soil, and the radicle is the first root to start absorbing soil moisture and nutrients.
Shortly after the root begins to absorb moisture, a shoot forms from the seed. The plant relies on natural gravitational forces to determine which way to grow. Sprouts grow up and emerge from the soil, reaching toward the sunlight.
Taproot and First True Leaf Forms
During this stage, growth is slow. The seedling still relies on its internal food stores to power all of the metabolic processes, but these stores are dwindling.
A large, central root forms, known as the taproot, and small secondary roots develop. This taproot is a specialized food storage system that will, in time, develop into a carrot.
The first true leaf appears now, too, resembling a smaller version of the mature leaves, and photosynthesis begins. The seedling is now capable of producing its own food.
Taproot Begins Lengthening and Expanding
Once photosynthesis begins, growth quickens. The taproot grows deeper into the soil, allowing it to access more moisture and nutrients in the root zone. It also begins expanding in width.
This stage is when the soil preparation becomes essential. If the taproot encounters rocks, hardpans, or other impenetrable layers, it will deform instead of growing straight down, as it needs to change its “route” to avoid obstacles.
It is critical now to ensure plants don’t receive an abundance of nitrogen fertilizer that promotes foliage growth. Instead, root crops need fertilizer with higher levels of phosphorus and potassium to encourage root growth.
Third True Leaf Forms
Growth is now occurring at a rapid pace. Hormones within the plant — known as phytohormones — continue to work in overdrive, developing new leaves. The third set of true leaves form to increase photosynthesis.
Tuber Expansion Continues
At this point, the carrot tops in your garden are filling out nicely and taking in sunlight to produce glucose within the leaves. This glucose not only fuels all of the cellular growth processes but begins to accumulate in the tuber.
During this stage of growth, keep the soil consistently watered to prevent the carrots from cracking. You will begin to see their “shoulders” at the soil surface.
Ready for Harvest
Approximately 75 to 80 days after planting, your plants are ready for harvest.
For many home gardeners, the life cycle halts here, and plants are pulled from the ground. However, if the plants are left in the soil, they continue through the second season of growth, reaching full maturation.
When temperatures drop, and the first hard frost hits, water within the carrot cells freeze, rupturing the cell walls. The tops die back to the soil surface.
Many home gardeners never let their carrots see the second season of their life, except for a small percentage that prefers to let their plants self seed.
If plants are allowed to overwinter in the ground, they begin to grow the following spring again to set seeds and complete their life cycle.
Flowering Stem Emerges
When springtime temperatures begin to climb, hormones will trigger cells to start elongating, much like when germination occurred the first spring. The root system developed the previous spring, so the plant can focus entirely on sending up a shoot.
This shoot turns into the flowering stem as it ages.
As air and soil temperatures start to climb in early summer, the carrot plants will quickly shoot up stems in a process called bolting. A plant bolts as it nears the end of its life cycle to produce seeds that will carry on its genetic information through future generations. These large umbrella-shaped structures known as umbels are the beginning of what becomes the seed heads.
Formation of Seeds
At this time, all of the food resources internally will be translocated from the carrots and used to set seed, making the tubers woody and fibrous.
Once seeds form, the plant no longer needs to grow — its life cycle is complete. After directing so many resources towards setting seeds, little remains to drive further growth. Phytohormones induce the genes driving senescence, and the carrot plants perish.