Germinating carrots is difficult enough without the added stress of summer heat. But it’s worth it because as the weather cools down, in fall, carrots will begin to thrive. Their roots will fatten up and you’ll get a much sweeter crop than you did in spring. So, if you’ve had trouble germinating carrots, don’t dismiss them just yet.
In this article, I’m going to show you how to get homogenous rows of carrots even in the hottest summer months – no patchy empty spots! And it’s so easy – no digging or crazy setups involved.
Carrots take a long time to germinate in spring when the weather is cool, but only take days to germinate in summer. The key to great germination is keeping the ground moist, cool, and shaded. You can accomplish this by using wood boards on top of your rows, cardboard, or fleece row covers.
Use this method for improving carrot germination
Now, if you’ve never tried this before, I suggest you go with the wood boards. In my experience, any shading cloth or fleece row cover material is too light to keep any real moisture or allow the ground to remain cool.
If you don’t have wood boards lying around, you can buy them and cut them to fit the width of your raised beds – you’ll only have to do this once, and any wood will do. It’s an effort, but you’ll be able to reuse the wood for this purpose for decades to come.
If wood is not an option for you at the moment, you surely must have some cardboard lying around. Use thick cardboard or multiple layers and secure it with rocks so that it doesn’t get blown away.
Germinating carrots in the summer time basically looks like this:
- Add fresh compost to your raised bed, filling it to the top – no digging required (your soil levels likely dropped after the previous harvest);
- Pre-water the compost a couple of days before sowing your carrots, and the day of sowing;
- Make shallow drills – 2cm / 1-inch max – in the fluffy compost (I like to press a wood board’s edge in the compost, and voila – rows are done);
- Sow the carrots and cover them lightly with compost- don’t press down too hard;
- Do your sowing in the evening, so your carrot seeds have a chance to establish and swell with water;
- Add the wood boards or cardboard on top of your rows;
- Water without removing the wood boards or cardboard – the water will run through;
- Water consistently (morning and night) for at least 5 days, and check daily for germination;
- When enough seeds have germinated, remove the wood boards but continue your watering routine.
Here’s a video I made describing this exact method. My spring carrots didn’t germinate so well because I experimented with fleece, so I returned to my trusted wood method.
Why this works
Carrots are fickle seeds. They need warmth to germinate – about 70°F (20°C), which they don’t get in early spring. They will germinate at 40°F though, but it will take a really long time – even as long as 21 days. Unfortunately, they can only be direct sown, as they hate having their roots disturbed or transplanted.
As for summer weather, carrots WILL germinate in the summer heat – they like temperatures as high as 85°F (30°C), but they hate dry, crusty soil. And in the dry months of July and August, keeping the ground constantly moist is a challenge.
The ‘wood boards’ method works because:
- It doesn’t allow humidity to escape from underneath the wood
- It doesn’t allow birds to come feast on an easy meal
- It provides a constantly cool and dark environment that’s perfect for germination
- It protects the delicate seeds from heavy summer rains and hail
- It allows water to seep through the cracks when watering
- It ensures easy, repeatable success with germinating carrots and any difficult seeds
The best part about this method is that you can use these same principles for getting stellar germination for any of the plants you’re struggling to grow directly in the ground. You just have to be careful not to leave the wood on top of the rows for too long, or you’ll get leggy, spindly seedlings.
Extra things to consider when planting carrots in the summer
First of all – it can be done. You CAN grow carrots in hot weather. And you CAN grow carrots in no-dig soil that, at this stage, may look a little hard and compacted – you just need the top layer to be fluffy.
Secondly, carrots will germinate much faster when it’s hot outside – mine germinated in 4-5 days in mid-July.
And thirdly, they will need much more water than you would use in spring, at least in the seedling stage.
You’ll want to sow your winter carrots 10-12 weeks before the first frost (that’s mid-July in my area) – and this will give you a nice fall harvest.
After carrots seeds germinate, make sure you give them some time to grow before you start weeding (if you have any weeds, that is). Carrot seedlings are delicate and small and you can easily pull them out accidentally when weeding.
On the same note, wait for a few weeks before thinning carrots. To give them enough room to grow, thin carrots every 1 1/2 to 2 inches apart, making sure you keep the strongest seedlings. (Oh, and try not to sow seeds too thickly, or you’ll have a lot of thinning to do). If you do the thinning early on, the carrot roots will have plenty of room to grow.
Unfortunately, carrots sown in summer seem to be far more susceptible to carrot root-fly damage than the ones sown in spring. Protect your carrots with insect netting and a simple frame as soon as you can – this is much easier if you have carrots in just one compact raised bed.
Carrots take about 70 to 80 days to germinate, so keep that in mind when sowing winter carrots. My favorite variety for winter storage is Berlikum, but I also love to have fun with multicolored, heirloom varieties.
- If you’re looking to have fun with heirloom carrot seeds, you can choose from this selection.
Lastly, you might not be aware of this, but carrots store for many months if given the right conditions – we ate our last carrots from the root cellar 6 months after harvest! The trick to keep them from shriveling is to bury them in sawdust or sand, in plastic bins with lids on top – they will last for ages.
Check this article if you’re interested in storing your harvest for a very long time.
Conclusion
Carrots are a staple in any gardener’s diet. That’s why so many of us sow carrots in succession so we can have them all year round. The only hurdle to get through is ensuring great germination every single time. Give carrots what they love: fluffy soil, good drainage, enough sunlight and humidity, and you’ll have a great harvest to last you through the winter months.
