If you are planning on growing carrots in your garden this year, you might be wondering how big they will get. That way, you can plan the number of plants and the amount of space you will need for your crop of carrots.
So, how big do carrots get? Carrots have roots that grow from 2 to 12 inches (5.1 to 30 centimeters) long and up to 1.5 inches (3.8 centimeters) wide, and have green tops that can grow up to 12 inches above the ground.
Of course, the quality of your carrots (if you get any at all!) depends on the care that you give your plants. Let’s take a closer look at carrots, including size, growing conditions, and time to maturity.
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How Big Do Carrots Get?
The roots of some miniature varieties of carrots may only get 2 to 3 inches (5.1 to 7.5 centimeters) long, while the roots of some can reach a length of 10 to 12 inches (25 to 30 centimeters).
Most of the time, carrots can reach a width of 1.5 to 2 inches (3.8 to 5.1 centimeters) at most. The green tops of carrots grow above ground, and can reach a height of up to 12 inches (30 centimeters) above ground.
How Do You Know When to Harvest Carrots?
You should harvest carrots when they are 0.5 to 1.5 inches (1.3 to 3.8 centimeters) in diameter. Smaller carrots will be sweeter and taste better.
If left to grow too long, or exposed to high temperatures, carrots will grow hard and fibrous, and will be tough to eat. On the other hand, carrots taste much better after a frost, since this encourages storage of sugar in the roots.
Depending on variety, they take 55 to 80 days (8 to 12 weeks) to grow from seed to mature carrot.
Finally, remember that carrots can take 2 to 3 weeks to germinate, so don’t worry if they don’t sprout within the first week!
Why Are My Carrots So Small?
There are many possible reasons that your carrots are small. It could be that you chose a variety that grows short, or it could be that the soil ran out of nutrients.
A lack of proper spacing between plants can also cause small carrots, due to competition with each other for nutrients and water. To solve this problem, thin your carrots after planting.
For more information, check out my article on how to thin seedlings.
You may get small carrots if the roots run into some type of hard object (such as a rock, root, or soil clump). However, this is more likely to cause deformed carrots than small carrots.
For more information, check out my article on why carrots get small, bumpy, cracked, or deformed.
What Do Carrots Look Like?
When they are still growing, only the green tops of carrots are visible. These green tops look somewhat like parsley or other herbs when they are young and small. As the carrots get older, the green tops grow a longer stalk.
The main root of a carrot is the part that we usually grow it for. The roots are usually orange, but there are many carrot varieties, some of which can have red, yellow, purple, or even white roots.
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Are Carrots Hard to Grow?
Carrots are a hardy, cool season biennial. This means that if they are left in the ground, they will produce seeds the 2nd year! Carrots are best planted in early spring.
Before sowing carrots seeds, make sure soil is smooth. There should be no rocks, roots, or soil clumps down to a depth of 1 foot (30 centimeters).
For more information on how to sift rocks out of soil, check out my article on how to remove rocks from soil.
A raised bed can work well as a place to keep sandy, smooth soil specifically for carrots.
The soil pH for carrots should be in the range of 6.0 to 6.8 (slightly acidic). Do not use compost or manure when growing carrots.
Sandy soil is smoother and softer, and is much better for growing carrots. It is ok to use mulch to protect carrots tops from the sun.
There are many other factors that affect carrot growth, including temperature, watering, fertilizing, and spacing. Let’s start with temperature.
Temperature for Carrots
The minimum temperature for carrot seed germination is 40 degrees Fahrenheit (4.4 degrees Celsius). If the soil is any colder than this, you will see low germination rates – that is, if you can get any seeds at all to germinate!
This is nature’s way of protecting carrot seeds from sprouting at a time when they will be unable to survive.
The maximum temperature for carrot seed germination is 95 degrees Fahrenheit (35 degrees Celsius). If the soil is any warmer than this, germination rates will decrease.
Combined with high humidity, high temperatures can encourage the growth of mold, which is another threat to your plants.
You should sow carrot seeds directly into the soil outdoors 3 to 5 weeks before the last spring frost date.
The ideal (optimal) temperature for carrot seed germination is between 65 degrees Fahrenheit (18.3 degrees Celsius) and 85 degrees Fahrenheit (29.4 degrees Celsius).
Keep in mind that these temperatures refer to soil temperature, not air temperature. If you want to find out the soil temperature, use a probe-type thermometer to check.
If the thermometer reads a temperature that is too low, then you have some options. One option is to wait until the sun warms up the soil.
To speed up this process, clear away any debris, such as leaves or grass clippings, from the soil surface. Also make sure to choose a location for planting that gets plenty of sun, so that it can warm up the soil faster.
If you are worried about a short growing season, you can also use a cloche (a plastic or glass cover) to trap some heat and warm up the air and soil near your carrot seeds.
A cloche can be made from a plastic water bottle to retain warmth and humidity in the soil for seeds or seedlings as they grow.
For more information, check out the table below, and check out this article from the University of California on ideal seed germination temperatures.
| Seed Germination Temperature | Temperature (degrees Fahrenheit) | Temperature (degrees Celsius) |
| Minimum | 40 | 4.4 |
| Ideal | 65 to 85 | 18.3 to 29.4 |
| Maximum | 95 | 35 |
Watering for Carrots
Carrots need regular watering. Keep the soil moist by watering frequently and shallowly. This is especially important in sandy soil, which drains quickly and does not hold water for long.
Putting mulch on top of your soil will help to retain moisture, especially during periods of hot, dry weather. If you find that you have a problem with dry soil, check out my article on how to treat dry soil.
On the other hand, over watering your carrot plants (or any plants for that matter) can lead to root rot and eventual death. The best way to decide when to water is to feel the soil with your fingers.
If the soil feels dry 2 or 3 inches below the surface, then go ahead and water. For more information, check out my article on over watering your plants.
Try to water early in the morning, rather than at night, to allow water to soak into the soil before evaporating.
Fertilizing for Carrots
You should not add compost or manure to your soil before planting carrots. Instead, use sandy soil, as mentioned above.
For more information, check out my article on the best soil for growing carrots.
After planting, use a nitrogen-based fertilizer (such as 21-0-0) 6 weeks after emergence of the carrot seedlings.
For more information, check out this article on carrots from the Utah State University Extension.
Spacing for Carrots
Carrots seeds should be sown directly into the ground outdoors. Do not transplant them, since they are delicate when young, and the roots (the part you want to eat!) can be damaged easily.
Sow carrot seeds 0.25 inches (0.6 centimeters) deep. When thinning, leave 3 to 4 inches (7.6 to 10.2 centimeters) between plants.
Also, make sure to leave 1 foot (30 centimeters) between rows of carrots to allow space for watering, weeding, fertilizing, and harvesting.
For more information, check out this article on carrots from the Old Farmer’s Almanac.
Conclusion
Now you have a much better idea of how big carrots get, in terms of both the root below ground and the greens above ground. You also know a bit more about the care that is necessary to ensure a healthy crop of carrots in this year’s garden.
I hope you found this article helpful – if so, please share it with someone else who can use the information.
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~Jonathon