7 Seed Starting Mixes Tested! Top Choice Was…

Curious which seed starting mix actually works best? In this video, we test 7 popular seed starting soils—from organic to conventional—to find out which one gives the strongest germination, healthiest roots, and fastest growth. Whether you’re a beginner gardener or a seasoned pro, these results might just surprise you!

We compare mixes based on:
• Seed germination rate
• Root development
• Water retention
• Algae, mold, and fungus issues
• Overall plant health

Don’t waste money on bad soil—watch this before you buy your seed starting mix!

Products Tested Include:
• Organic & conventional seed starting mixes
• Peat-based and peat-free blends
• DIY and store-bought options

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👩🏻‍🦰 A B O U T M E:
Ashley has had a passion for plants since she was a small child. In the long summers as a child, she would garden alongside her grandmother and it was then that she realized her love for greenery. With years of great studying, Ashley had begun her post-secondary education at the University of Saskatchewan.
At first, her second love, animals, was the career path she chose but while doing her undergrad she realized that her education would take her elsewhere. And with that, four years later she graduated from the University of Saskatchewan with a bachelor’s degree in science and a major in Soil Science.
Some of Ashley’s interests are YouTube, in which she posts informative videos about plants and gardening. The focus of Ashley’s YouTube channel is to bring science to gardening in a way that is informative but also helpful to others learning to garden. She also talks about the importance of having your own garden and the joys of gardening indoors. Ashley continues to study plants in her free time and hopes to expand her YouTube channel as well as her reach to up-and-coming gardeners.
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[GardeningInCanada]

GIC Crew here are your 🔗’s!




Peat pods with cotton (no netting) -

[Garden-nq]

Your channel, content, and topics are the BEST. Hands down my favorite channel. As a lifelong gardener, you always answer the things that I've spent years testing myself. I truly appreciate you! Thank you! ❤

[nicohelpdesk]

You should test out sand. Which should be fairly similar to vermiculite / perlite. Have seen someone doing sprouts with sand with great results

[AcrylDame]

I germinated my peppers in perlite and added a "start fertilizer" very high in phosphorous. Great results, can recommend.

[arshsingh]

I like having the best of both world with seed starting mix and vermiculite. I fill the cells up basically most of the way with seed starting mix and put the seeds on top. Then I sprinkle a layer of vermiculite on top, seems to work great for me at least :)

[hughbrackett]

I got good results for peppers using sifted rotted wood chips. I put them through a quarter inch screen.
I had problems starting tomatoes in the large mesh pods. After planting out, they weren’t growing as expected. I dig one up and found the roots weren’t getting out of the mesh cover. I ended up digging them all up and slicing up the mesh with a razor knife. The plants did fine after that.

[Plug]

Your vermiculite trick worked extremely well with my German chamomile and lavender poppy seeds.. I just use it as a topping though.
Thank you

[DahVoozel]

Definitly experienced spotty, slow and salty with the Miracle Grow starting mix this year.

[LEDewey_MD]

Awesome video! (Also explained why my last seeds planted a few weeks ago failed!) Garden on! 😊

[OrbitalCookie]

Good information. This leaves me wondering, however, what is the actual optimal seed starting medium, including the way it's watered. It would be nice if the water was not shared between the test cases.

I had tried completely different setup, 2 cases basically:
- Coco coir tablets. I jammed the expanded tablets in the same tray you have used in the video (don't do that, it's hard to take out). I noticed they have property of holding moisture very evenly (very good capillary action), but when it's gone, it's suddenly gone and the seeds are dry. I think that the seedlings are between two extremes - constantly soaked or starving for water. I recommend potting up any seedlings that germinated in pure coco coir ASAP.
- Plain potting mix for the peppers/tomatoes, which I manually sifted and removed any big chunks. It was mostly fine peat. It had 15-10-16 fertilizer. It had this property of clumping up, when watered, it tends to get compact. Harder to remove seedling roots than from coco coir. I think it holds water well, has good capillary action. But I had great success with it - almost everything germinated.

In both cases I have not left the tray in water. I just let the trays to soak up the water for a minute and then left them be. It felt like it would get way too damp otherwise, with these particular growing mediums.
I did not like the stress of coco coir. I liked the piece of mind the peat with some fertilizer gave me. Now I am wondering how best to improve it for the next season. I am probably going to add something to help roots breathe more and ensure the soil does not clump up. I have time, so I might mix in the coco coir into the peat, to make it more loose, and also add quite a bit of perlite. Not sure about vermiculite, both growing mediums hold the moisture little too well.

Ah, forgot to mention - what's annoying about the coco coir is washing it. And "buffering". Not sure about the science of that, at all.

[johannebilodeau]

Great gardener!thank you so much for audio translation! Very usefull!

[BigWillDoggintheSoil]

Hydro Crunch Coconut Coir is the brand I tend to buy most. It’s usually available on Amazon and is triple washed and treated to avoid magnesium and phosphorus lockout.

[Plug]

I only use coconut coir as a medium for my tarantulas.... For growing stick with some sort of peat mixture. (Peat, vermiculite, worm castings, small amount of lime to offset peat acidity.)

[Wanhope]

Heatmat for peppers do better with a dome. Then gradually adjusting airflow. They really love the higher humidity

[Gardenfrog]

Thanks for the results of your experiments with seed starting in different mediums. Interesting results. Speaking of experiments, have you tried sowing in early spring under cloches in your garden beds? I have done winter sowing in milk jugs but this year I’m thinking I might sow my broccoli and cabbage directly in the beds and putting a milk jug with the bottom cut out over top as a cloche. Sort of no transplant winter sowing.

[leahnichol]

Well, that was interesting. None of those seed starting mixes look like what I have been using. It is the only thing I have used (I am new so no judgement there.). It is Gardenworks organic seed starting mix. It says it is peat mass, coconut coir, aged organic compost, organic soil, natural zeolite, organic kelp, and perlite. Minimum guarantee is nitrogen 0.1%, phosphoric acid 0.04%, soluble potash 0.1% moisture 60% and organic matter 30%. It looks tan when dry and dark when wet. So very low ferts and high moisture retention. It has been working well for me so far. I have been growing pretty straight forward things this year.

[danielburns]

Found the jiffy pellets with the mesh are best used for small seed like tyme and other herbs.I use the same green starters with domes and like the way they preform for peppers and tomato good job.

[raypearce]

I've had good luck with rockwool and a weak hydroponic mixture

[cjvilleneuve]

Thanks again, , this might be a soil problem that made me loose my precious seed😢😢, , iwill transfer the only one that germinated into another kind of soil....bt w ialso used fluval clay soil into little moss terrarium, , it is unbelivable, , in glass ball smaller than my head i had over 20 species of moss growing beside another, i had to make sure some wouldbnot choke other, but it was so cool to look at, i was hypnotise by this thing, that i made it into a the suspended light over the kitchen table 😂😂😂.

[aperturist]

It's so interesting how the wild card preformed! I'd love to see more tests with it