If want to grow carrots this year, it helps to know how long they take to germinate (sprout). That way, you can plan ahead for when to start them in the garden.
So, how long do carrot seeds take to germinate? Carrot seeds take 6 to 10 days to germinate under optimal conditions. Carrot seeds germinate faster with proper soil temperature, humidity, and air circulation. You can speed up the germination process by putting the carrot seeds in a humidity dome (purchased or homemade) and keeping the soil at 65 to 85 degrees Fahrenheit (18 to 29 degrees Celsius).
You can see how soil temperature affects seed germination with this app I made!
There are also several factors that affect how fast carrot plants will grow after germination, including water and soil quality.
In this article, we’ll start by looking at how temperature affects carrot seed germination time. Then we’ll go over some ways to speed up carrot seed germination and how to help them grow faster after they sprout.
Let’s get started.
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How Long Do Carrot Seeds Take To Germinate?
Carrot seeds will take 6 to 10 days to germinate under ideal conditions, including:
- Soil temperature at 65 to 85 degrees Fahrenheit (18 to 29 degrees Celsius)
- Soil that is moist but not soggy (do not allow the seeds to dry out or sit in too much water!)
- Soil that gets proper aeration (do not compact the soil!)
- Seeds that are healthy and new (old seeds have a lower germination rate)
Without the proper conditions, carrot seeds can take over 7 weeks to germinate (if they ever sprout at all!)
If you have been waiting for your seeds to sprout, you might be wondering why carrots take so long to germinate. One of the most important factors for carrot seed germination is soil temperature, so we’ll start there.
What Temperature Do Carrot Seeds Need To Germinate? (How Time Varies With Temperature)
According to both Cornell University and the Michigan State University Extension, carrot seeds will germinate within 7 to 21 days under ideal conditions. However, it may take quite a bit longer at borderline temperatures on the low end (around 40 degrees Fahrenheit, or 4 degrees Celsius).
For example, if soil temperatures are lower than 40 degrees Fahrenheit (4 degrees Celsius), you may fail to see any germination at all. If you do, it is likely to take up to 51 days (over 7 weeks!) for carrot seeds to germinate at such low soil temperatures.
You will also see a relatively low germination rate (the percentage of planted carrot seeds that sprout).
You can learn more about germination rates and how to test seed viability in my article here.
Image courtesy of user:
John Elson via:
Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Carrotdime.jpg
In slightly warmer soil temperatures in the 50s Fahrenheit (10 to 15 degrees Celsius), it will take 10 to 17 days (about 1.5 to 2.5 weeks) for carrot seeds to germinate. You should see better germination rates in this case.
In warmer soil temperatures between 68 and 95 degrees Fahrenheit (20 to 35 degrees Celsius), carrot seeds can germinate in 6 to 10 days. The germination rate will be much higher in this scenario.
For a summary, check out the table below, and for more information, check out this article from the University of California on ideal seed germination temperatures.
| Soil Temp Range | Temp (Degrees F) | Temp (Degrees C) |
|---|---|---|
| Min | 40 | 4 |
| Ideal | 65 to 85 | 18 to 29 |
| Max | 95 | 34 |
maximum temperatures for
carrot seed germination.
How To Speed Up Carrot Seed Germination
Generally, carrot seeds should be planted directly into the garden in the spring (also known as direct sowing). The reason is that carrots do not transplant well after they germinate and start to grow.
You can choose your planting date based on the last spring frost. Cornell suggests planting carrot seeds outdoors 2 to 3 weeks before the last spring frost date.
You can find the last spring frost date in your area with this tool from the Old Farmer’s Almanac.
Mother Nature is a bit harder to control than the conditions in your house. However, there are ways to speed up germination even when you have to start seeds outside.
Keep Carrot Seeds & Their Soil Warm
One way to keep carrot seeds and soil warm is to cover the soil with plastic (clear or black). Then, just sit back as you watch the sun work its magic.
The warm rays from our favorite star will heat up the air and soil underneath the plastic. This will let you plant carrot seeds a bit earlier than normal (or speed up germination if you are impatient!)
You can also use a cloche to cover carrot seeds and keep them warmer. A cloche is a covering (usually made of plastic) that protects seeds or seedlings from cold, pests, wind, and other outdoor dangers in the garden.
A cloche will help to trap the sun’s heat in the air, and some of that heat will get trapped in the soil as well. This extra heat will help carrot seeds to germinate faster.
You can use a clear plastic milk or water jug as a cloche. Just cut out the bottom and put the whole thing over the spot where you planted the seeds.
A word of warning: don’t let the plant get too hot after it germinates! You can remove the cap of the plastic jug to create an air vent, which will cool things down inside the cloche.
A cold frame or greenhouse is another option to keep carrot seeds (and other plants) warm as they germinate and grow.
You can learn more about ways to keep seeds warm (indoors or outdoors) in my article here.
Keep Carrot Seeds & Their Soil Moist
Aside from maintaining the proper soil temperature, there are some other ways to help your carrot seeds to germinate faster. One of the best ways is to keep the seeds (and their soil) moist.
Even at the ideal soil temperature, carrot seeds will not germinate without enough water. In fact, they will die if they dry out after germination begins.
After sowing carrot seeds in the garden, keep the soil moist by watering as often as necessary. The goal is to keep the soil continuously moist, but not soggy (it should never be wet enough to wash away seeds or soil).
Keep Carrot Seeds At The Right Humidity Level
Humidity is another important factor to consider when germinating carrot seeds. If the air is too dry, then the soil will dry out faster, and the seeds will have trouble germinating.
Image courtesy of user:
Dwight Sipler via:
Wikimedia Commons: https://commons.wikimedia.org/wiki/File:
Carrots_are_up_(2634523693).jpg
Humid air increases the chances that the soil will stay too wet after watering or rain. This can lead to damping off, which happens when affects seeds or seedlings.
Damping off is more likely when humidity is high, soil is wet, and temperatures are cool. For more information, check out my article on damping off of seedlings.
If you find that you have trouble maintaining soil moisture and air humidity, you have some options. One idea is to use a cloche as a makeshift humidity dome.
A humidity dome traps moisture in the air underneath it so that seeds have the humid environment they need to germinate properly. A humidity dome will also help the soil to retain moisture.
This will speed up seed germination, increase germination rates, and reduce the time needed to keep soil moist.
For more information, check out my article on humidity domes.
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Keep The Soil Aerated For Carrot Seeds
In addition to soil and warmth, seeds need also air, just like seedlings and established plants. In fact, they “breathe” to convert oxygen and stored carbohydrates into energy for growth (just as we do!)
If the soil is too wet, it will lead to a lack of oxygen in the soil. Without enough air circulation, your seeds may succumb before they have a chance to germinate.
To keep your seeds from suffocating, there are two key actions you can take:
- First, keep the soil moist (but not wet.) Avoid over watering, and consider using a cloche to keep soil moisture and air humidity at the right level.
- Second, keep the soil loose. Avoid soil compaction – do not push down on soil before or after planting your seeds. Also, avoid walking on the soil! More space between soil particles means more space for air and water (both of which are necessary for seed germination.)
Use New Carrot Seeds For Higher Germination Rates
Even with the proper soil temperature, moisture, and aeration, germination can still fail with old seeds.
For best results, use new carrot seeds, rather than old ones. Newer seeds have a higher germination rate (older seeds will germinate at a lower rate, or not at all.)
Generally, carrot seeds last about 3 years. Beyond that time, the germination rate decreases rapidly.
For more information on the lifespan of carrots and other seeds, check out my article on how long seeds will last.
Can You Germinate Carrot Seeds In A Paper Towel?
You can germinate carrot seeds in a paper towel (without any soil!) However, remember that it is always best to direct sow carrot seeds into soil in the garden (since they do not transplant well!)
The paper towel retains moisture while still letting the seeds breathe. The paper towel also replaces soil, serving as an alternative growing medium.
To germinate carrot seeds on a paper towel, follow these steps:
- First, wet the paper towel until it is damp (but not soaking wet).
- Next, lay out the carrot seeds so that they are separated (not touching).
- Then, put the damp paper towel & seeds in a plastic bag (to help retain moisture).
- Finally, put the bag in a warm spot (to encourage faster seed germination).
The drawback of this approach is that you need to transplant the sprouted seeds into soil by hand. This is tricky with carrots, since the roots are easily damaged (and they make up most of the plant).
How To Help Carrots Grow Better
If you get a few important things right, your carrots will grow better after sprouting. The key factors are:
- Planting time
- Seed spacing and thinning
- Watering
- Fertilizing
First things first: let’s begin with planting time.
Choose The Best Time To Plant Carrot Seeds
As we learned earlier, soil temperature has a big impact on how long carrot seeds take to germinate. If you plant them too early, a hard frost may kill the seeds or cause young plants to bolt.
Even when they are safe from frost, carrot seeds will germinate slowly (if at all!) when soil temperatures are too cool (below 50 degrees Fahrenheit, or 10 degrees Celsius).
So, when is the right time to plant carrots? The soil should be at least 45 degrees Fahrenheit (7 degrees Celsius).
Generally, this means 2 or 3 weeks before the last spring frost date.
For more information, check out this frost date calculator from the Old Farmer’s Almanac
Use Proper Spacing & Seed Depth For Carrot Seeds
Carrot seeds should be planted about 0.5 inches deep and 1 inch (2.5 centimeters) apart. Later in the season (after germination occurs), thin the seeds to 3 inches (7.5 centimeters) apart.
This will give each plant enough space to grow without competition from neighbors. You can learn more about how and when to thin seedlings in my article here.
Leave 1 to 2 feet between rows (or more if you have the space). This will make it easier to water, fertilize, pull weeds, and harvest later in the season.
Depending on the variety, the carrots themselves can grow up to a foot long. So, if growing in a container, give them enough depth to grow to full size.
For more information about carrot seed spacing, check out my article on how much depth and space carrots need to grow.
Water Carrot Plants Properly
Carrots need plenty of moisture to grow. When watering, soak the soil at less frequent intervals, rather than watering shallowly too often.
You may need to water more often during hot and dry weather, or if your garden has dry soil.
The best soil for growing carrots is sandy, loose, and well-draining, with plenty of organic material. Loose soil is ideal for the root (the part of the carrot we eat!) to grow long and straight without rocks, roots, or soil clumps getting in the way.
You can learn more about the best soil for growing carrots in my article here.
Fertilize Carrot Plants Properly
According to the University of Minnesota Extension, the ideal soil pH for carrots is between 6.0 and 7.0 (slightly acidic to neutral). You can improve nutrient content and soil structure by adding compost in spring or fall.
For more information, check out my article on how to make your own compost, and my article on where to buy compost.
You can also try a balanced fertilizer, such as 10-10-10, to provide extra nutrients. If you are not sure what this means, check out my article on NPK ratios.
Just be sure to avoid fertilizers with herbicides. According to the South Dakota State University Extension, these herbicides can kill weeds and desirable plants alike.
Before you add any fertilizer or supplements to your garden, get a soil test to make sure you really need it! Otherwise, you may be over fertilizing your plants, which can burn them.
For more information, check out my article on how to do a soil test.
Why Are My Carrot Seeds Not Germinating?
If your carrot seeds are not germinating, here are some of the most common causes to look out for:
- Improper temperature – if the soil is too cold (or too hot), carrot seeds will not germinate. At temperatures below 40 degrees Fahrenheit (4 degrees Celsius), expect germination to be slow if it happens at all.
- Improper watering – if seeds dry out during germination, they will die. On the other hand, keeping the soil soggy will prevent the seeds from breathing, which will also kill them. Wet soil can also cause damping off, which can kill seeds or seedling. Keep the soil moist, but not soaked.
- Compacted soil – seeds need to breathe, just like seedlings and established plants. If you compact the soil by walking on it or pressing it down, there is less space for air and water. This can be enough to slow or prevent carrot seed germination.
- Old seeds – if your carrot seeds are more than 3 years old, their germination rate will decline. If a few of the seeds you planted are germinating, but most are not, then old seeds could be the culprit. Use newer seeds for better results.
Conclusion
Hopefully this article gave you an idea of how much time it takes carrot seeds to germinate (6 to 10 days under ideal conditions). You also know how to speed up the process.
Remember that temperature and moisture are two of the key factors in getting carrot seeds to germinate.
Carrot seeds are small, and it can be tough to plant them. You can learn some easy ways to sow small seeds here.
I hope you found this article helpful. If so, please share it with someone who can use the information.
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~Jonathon