Carrots can be difficult to germinate because they are sensitive to a lack of moisture. However, with the right techniques, you can improve your carrot seed germination rates and get a better carrot crop.
Great Carrot Crops Start With Good Carrot Seed Germination
1. Prepare the Soil
Fine, Loose Soil
Carrots like a well-drained, loose soil that’s free of stones and clumps. This allows the tiny seeds to establish roots easily and the carrot to form properly. Till the soil deeply (at least 30cm or 12 inches) and remove any debris for best results.
pH Balance
Carrots prefer a slightly acidic to neutral pH (6.0 to 7.0). Test your soil and amend it if necessary. To raise the pH and lower acidity or sweeten the soil (as the old gardeners would describe it), add lime. To lower pH and increase acidity you can add sulphate of ammonia or urea which are high nitrogen fertilizers or sulphur.
2. Pre-Soak the Seeds
Carrot seeds have a hard outer shell that can slow down germination. Soak the seeds in warm water for 24 hours before planting. This softens the seed coat and helps speed up the process.
3. Chit the Seeds
Some advice from The Wartime Weekend Gardener published in 1940!
… but there is a little indoor job we might do during the evening, and that is “chitting” the Carrot seed ready for sowing. Not many amateur gardeners take the trouble to do this , but I strongly advise it, because with Carrots a good start is everything.
It is not a long job either. Take a clean piece of flat boarding and moisten it. Now spread out the Carrot seed on this, making sure, as far as possible, that one seed does not touch another, A large darning needle is an ideal tool for separating them when you have laid them out on the board.
Now set the board on a sunny window-ledge or in some similar position. See that the board is kept damp but never too wet. Soon you will see the seed beginning to germinate, and when that happens we can sow with a light heart, know that it has a good start.
4. Moisture Management for Germination
Consistent Moisture Improves Carrot Seed Germination
Carrot seeds need consistent moisture to germinate. After planting, water the seeds gently but thoroughly, and keep the soil consistently moist until the seeds sprout. Avoid letting the soil dry out, as this can delay or prevent germination.
Worse still, a dry spell just after the seed has begun to germinate can kill the seed / seedling resulting in no carrot seed germination at all.
Cover with Sacking or a Board
To retain moisture, lay a piece of sacking, a wooden board, or horticultural fleece over the seedbed after sowing. Check daily, and remove the cover as soon as you see seedlings emerging, usually within 7-14 days.
Be aware that slugs like to congregate under boards and will feast on tender seedlings. Turn the boards over at least once a day to check.
Water Daily
In dry weather, water daily. If the sun is strong you may need to water two or three times a day. Use a fine rose on watering cans and if using a hosepipe with a sprayer, a mist setting is ideal.
Water prior to sowing
Before sowing water the seedbed well. Just prior to sowing, use a watering can without a rose to soak the sowing drill.
5. Sowing Depth & Covering
Proper Depth
Sow carrot seeds shallowly, about ½ cm or ¼ inch deep. They need light to germinate, so don’t bury them too deeply. A light covering of sand or vermiculite will hold the seeds in place.
Ensure the seeds have good contact with the soil. After sowing, lightly press them into the soil. I just pat along the row with my fingertips to do this.
6. Fluid Sowing
Fluid sowing not only spaces seeds, the sowing gel also ensures the seeds remain moist and thereby improves germination. Read more on Fluid Sowing here.
7. Temperature Control
Optimum Carrot Seed Germination Temperature
Carrots will germinate in a wide range of temperatures, from 4ºC to 35ºC. Their optimum temperature is surprisingly high, 27ºC. At that temperature they will germinate in just 4 days on average.
Carrot Seed Germination Temperature Range
Practically carrot seeds germinate best in soil temperatures between 13-24°C. If it’s too cold, germination can be slow or erratic. In cooler climates, wait until the soil has warmed up, or use a cloche or row cover to warm the soil.
8. Control Slugs
Slugs can be a real problem with newly emerged seedlings. At times I have thought seeds had not germinated when in fact they had germinated but been eaten almost immediately on emerging from the soil
9. Mulching
After the seeds have germinated, a very light layer of mulch can help retain soil moisture and keep the soil temperature stable. Just make sure the mulch is fine and not too heavy, as heavy mulch will hinder the growth of the delicate seedlings.
10. Patience
Be Patient! Carrots can take 1-3 weeks to germinate in cool weather, so be patient. Resist the urge to disturb the soil or plant something else over the seeds if you don’t see immediate results.
Sowing a few radish into the drills will serve to mark them clearly.
By carefully managing moisture, soil conditions, and temperature, you can significantly improve the germination of your carrot seeds, leading to a healthier and more abundant crop.
Further Information on Carrots
- Growing Carrots – How to Grow Carrots
- Carrot Growing Tips – Carrot Fly, Growing & Harvesting
- Growing Long Carrots for Show – Long Rooted Carrots
- Growing Stump Rooted Carrots for Show – Preparation
- Growing Stump Rooted Carrots for Show – Cultivation to Showing
