Soil vs Hydroponic Microgreens: Why We Grow the Way We Do
Even though microgreens are relatively new to the farming industry, there is a plethora of grow mediums to choose from. Originally, it all started with trays of soil. Then came coco coir, flood systems, and the Kratky method—the list goes on.
To keep this short and sweet, let's dive straight into the great debate: soil vs. hydroponics.
How The Microgreens Industry Came About
Have you wondered how the microgreens industry was born? I actually have.
You cannot quote me on this, but I think it went something like this: I believe a person with a small garden was doing their annual "seed starts" inside "X" number of weeks before their area's last frost date. They had individual small pots laid out in standard-size grow trays.
In the wings, they had grow lights on timers ready to turn on when needed—all in a room that was much warmer than the colder temperatures outside.
They filled each pot with a good grade starter soil mix that had plenty of nutrients. Next, they made sure the moisture content of the soil was like the bed for Goldilocks' nap: "just right." For some reason, they heavily over sowed the seeds in those small pots. Then, they covered the pots for the germination stage.
Once the seeds germinated, they removed the cover and placed them under the grow light to continue the growing cycle. They watered them and let the timers on the lights go on and off to mimic day and night outside.
Part of the seed growing cycle is to thin the germinated seedlings down to the single strongest one 🌱 to give it room to grow.
Well, I think they got busy or just forgot. By the time they remembered, it was too late—they had a dense canopy of tiny plants at the first true leaf stage.
"Humm, let's see where this can go..." 🤔
On the second attempt, they did away with the individual pots. They did the same over sow process and, in the end, created a full tray of tiny plants at the first true leaf stage. 💡
A new form of farming was born: Urban Farming (Indoor Farming) of tiny "Micro" green leaves. Microgreens. That small idea has grown (pun intended) into a thriving industry.
Soil Trays: The Original Microgreens Grow Method
Originally, a standard soil setup includes:
* **Three standard 10x20 grow trays:** Two without holes and one with drainage holes.
* **A good quality soil mix:** A mix that holds moisture yet drains well becomes the perfect nutrient-packed medium to support the plants until harvest, right when their first true leaves form.
* **A heavy weight:** Growers use a weight, like a brick, to put the necessary pressure on the seeds so the roots sink deeply into the medium.
* **Grow lights with timers:** To mimic the natural day/night cycle required for steady growth.
* **Ventilation fans:** These mimic the winds of nature against the stems.
> 💡 **Pro-Tip:** The fans serve a dual purpose: they promote stability and strength in the plant's stems to support the expanding leaves, and they prevent mold growth within the dense canopy.
Hydroponic Trays: Modified Microgreens Grow Method
A hydroponic setup is hardware-wise identical to the standard soil method, with the sole exception of the grow medium used. While there is a myriad of hydroponic mediums out there, my preference is a mesh silicone mat—just like the ones used in dehydrating systems.
The tray that holds the grow medium has holes to allow for proper hydration.
* **In the soil method,** those holes allow water to escape into the reservoir tray so the soil doesn't get waterlogged.
* **In the hydroponic method,** those holes allow the roots to grow directly down into the water reservoir to access their nutrients.
Because most microgreen varieties have incredibly small seeds, using a standard holed tray alone wouldn't work. Have you ever heard the scripture, "If you have faith as small as a mustard seed, you can say to this mountain, "Move from here to there," and it will move."? 📜 Have you ever actually seen a mustard seed? They are teeny-tiny! 🔍 They are so small they would fall right through the standard holed tray holes.
That is where the silicone mat comes in. Because its mesh holes are much smaller, the silicone safely suspends the seeds out of the water to germinate, allowing them to send their roots down into the water reservoir below.
It keeps the main plant stems and leaves growing cleanly above the waterline, while the roots thrive in the nutrient-rich grow solution in the reservoir below. Because the delicate canopy is elevated entirely away from the root system where harmful bacteria usually like to hide, it prevents contamination. This clean, physical separation is exactly why indoor-grown hydroponic microgreens are so much safer than traditional sprouts!
Soil vs Hydroponic: Why We Grow the Way We Do
When choosing how to cultivate microgreens, the grow medium changes everything from daily labor to final safety.
No dirt, no heavy lifting, just thriving greens. 🚫💪 Here at Tasty Little Leaves Microgreens. LLC, we skipped the original soil route entirely for a system that’s clean, lightweight, and highly efficient.
Hardware-wise, both setups are completely identical. They use the exact same trays, the exact same lights, and the exact same fans. The only true exception is the grow medium itself. But for me, that single difference changed everything. It all came down to the heavy weight of the trays and what happens *after* the harvest.
With the soil method, that grow medium becomes a single-use waste product. Unlike the plastic trays, you can't just wash it and reuse it. Instead, you're left with a heavy, dense block packed tight with entangled roots that has to be thrown away.
With the hydroponic method, the silicone grow medium is simply scraped clean, washed, and sanitized. It is used over and over again.
After harvest, wet soil trays are incredibly heavy. Because I am unsteady when walking, managing that kind of awkward, heavy lifting on a weekly basis just wasn't safe or sustainable for me. With the hydroponic method, the trays are essentially empty at harvest. Yes, they still have to be cleaned and readied for the next grow rotation, but it is a lightweight task I can manage.
Now, add the logistical nightmare of disposing of that dense soil waste. And let's be honest, there is a lot of it!
Let's look at the math using a modest setup of just 5 trays: 5 trays multiplied by every grow rotation. Using an average 12-day grow cycle, that is roughly 25 rotations a year. That equals **125 trays of heavy, dense waste** you have to find a place for every single year.
We won't even dwell on the other issue staring us right in the face: 💲💲 the constant financial cost of purchasing and shipping heavy soil, and then paying to dispose of it.
Yes, I compost for my personal outdoor garden. But remember, I'm an urban farmer. I live in the city, and quite honestly, I do not have the physical strength, the space, or the desire to be both a premium microgreen grower *and* a commercial compost manufacturer.
Why Hydroponic Microgreens Win for Urban Farming
So, the Soil vs Hydroponics debate? For Tasty Little Leaves Microgreens, LLC, it’s no contest. 💧🌱 Not only is hydroponics incredibly clean (perfect for keeping things sterile indoors!), it completely gets rid of the heavy lifting. Bonus: Just look at those healthy roots!
🛒 Ready to add some crunch to your next meal prep? We plant every tray to order so your microgreens are as fresh as physically possible. Take a look at our full lineup of varieties and claim a spot in our next grow rotation!
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