Testing How To Best Germinate Coriander Seeds

I grow a lot of cilantro. Or coriander, as you may prefer to call it. But regardless of name, the seeds can take time to germinate. And it is a challenging wait.

Waiting 2-3 weeks or longer for the seeds to germinate and sprout the first leaves is not unusual.

And face it, before the seeds germinate, we just do not know if we planted a “dud” or a healthy, viable seed.

It does not help that the expected germination rate is far from a perfect 100%.

Here, I set out to find the best way to germinate coriander seeds to grow cilantro.

Looking for a quick answer? Gently crushing the seeds and removing the husk proved to be the most effective way to germinate coriander or cilantro seeds in my test.

Looking For a Better Way to Germinate Coriander Seeds

I have always planted coriander seeds straight from the seed packet. And it has overall worked well.

And when I grow cilantro from seed, I am a classic over-seeder. I use too many seeds per starter pot to maximize my chances and deal with the risk of overcrowding later.

But surely there must be a better way to germinate coriander seeds? Imagine if we could shorten the time it takes to identify bad seeds.

I prefer over-seeding to pre-germinating coriander seeds as the roots that form are oh-so delicate and difficult to handle.

I decided to test three different methods of prepping the seeds before I sow. 

The plan is to see if the germination time between the three methods will differ.

  1. Seeds straight from the seed packet
  2. Soaking seeds for 48 hours before planting
  3. Expose the actual seed by gently crushing the surrounding husk

Testing 3 Ways to Germinate Coriander Seeds

Here are the rules: 

  • I will use a 50/50 blend of cactus soil mix and regular potting soil and use plastic recyclable starter pots (7 centimeters/ 3 inches).
  • Progress is checked and reported every week. I will pick the winner when the first seedlings are large enough to be transplanted into a larger pot.
  • Eight (8) seeds are planted in each pot, and I need at least two healthy seedlings from any given pot to call a winner.

Start (Day 0): Planting 3 Sets of Seeds

Having prepared the pots, I planted the three sets of 8 seeds in separate labeled pots.

I put a thin layer of vermiculite on top of the soil after planting the seeds to help retain moisture.

I used the same number of seeds (8) for each pot. The soaked seeds and the seeds straight from the seed packet were placed in different holes around the pot.

The crushed seeds were sprinkled across the soil and then covered with a layer of potting soil and a thin layer of vermiculite.

Week 1 (Day 1-7): Crushed Coriander seeds taking the lead

I have to say I am surprised to see the first leaves within as little as one week of planting the seeds.

You may have your favorite, but crushing the seeds seems the most effective way to germinate them faster. 

In a way, it seems logical; seeds in a husk would take longer to germinate, right?

Today, exactly one week after planting the crushed coriander seeds, I see two sets of first leaves.

And the larger of the two sprouted already after four days!

Crushed coriander seeds germinating already week 1
Two sets of first leaves from crushed seeds in week 1.

It would, however, be premature to pick the winner. I need at least 2 strong seedlings with true leaves that will cope with being transplanted.

It will be interesting to see if crushing the seed will affect how quickly the seedling will grow.

And will the seedling grow big from a crushed seed?

Could it be that the other methods catch up?

Stay tuned.

Week 2 (Day 8-14): Soaked & Package Seeds Lagging Behind

The short answer is that the crushed coriander seeds still show the best result.

The soaked seed and the seed taken from the packet is lagging. 

I see the first leaves from the seeds that were soaked for 48 hours before planting. 

The seeds planted straight from the packet show no signs of sprouting first leaves.

Still – as you can see from the photo – the seedlings from the crushed seeds are doing well. I see true leaves from 3 out of 8 seeds and first leaves from 2 more.

Crushed coriander seeds with true leaves in less than 2 weeks.
Crushed coriander seeds sprouting true leaves in less than two weeks.

This gives us 5 out of 8 seeds germinating within 14 days of planting.

As a side note, I have planted new batches of coriander seeds using the same principle – soaked, crushed, and seeds straight from the packet.

If I can replicate the result with this second batch, I will be ready to call a winner next week.

Time will tell. Stay tuned.

Week 3: (Day 15-21): Will Crushed Coriander Seeds Still Be Ahead

I can honestly say that I expected this to be a closer race.

Crushed coriander seeds outperforming soaked and natural seeds
Crushed coriander seeds outperform the soaked seeds in second place.

But now, I feel comfortable stating that crushed coriander seeds germinate faster.

I saw true leaves from the crushed seeds last week (week 2). I am still not seeing true leaves from the soaked or natural coriander seeds.

And yes, I have grown several test pots to confirm the findings, which still hold.

On a side note, I can almost get soaked seeds to germinate as fast as crushed seeds. But not every time. 

But soaking seeds is more work as we have to wait 48 hours before we can plant the seeds.

It is not a big deal, but it is still not as straightforward as gently crushing the seeds and planting them immediately.

Conclusion: Cilantro Growing Germination Test

This is no test that would hold up to academic scrutiny.

Still, I believe the findings to be true and have value.

I have replicated and consistently found that seeds will germinate faster if they are gently crushed, and the husk is removed.

I will use crushed cilantro seeds when starting the seeds indoors or outdoors from now on. 

Mattias Magnusson: Hello, I'm Mattias, a passionate and experienced gardening enthusiast. I am the creator of MattMagnusson.com, your guide to year-round herb and veggie growing. Let's simplify green living, no matter your space or location.