The Best Hydroponic Grow Mediums for Microgreens (Ranked from Worst to Best)

February 3, 2023

Hydroponics is the practice of growing plants in water without using soil. It's one of many "aquaculture" methods, and over the past 7+ years it's become the way we grow nearly all of our microgreens at On The Grow. The reason we love hydroponic growing is the level of control and the long list of grow medium options. You can mix and match different mediums with different nutrient programs to dial in exactly the right recipe for your crop, your space, and your operation.

To grow microgreens hydroponically, you'll typically use a "growing medium" instead of soil. The medium gives the roots something to grab onto so the plant can stand itself up and grow well. Some crops, like pea microgreens, are aggressive enough rooters that they can be grown directly on a bare mesh tray with no medium at all. Most microgreens, though, will grow faster, stronger, and more evenly with a good medium underneath them. The job of the medium is to hold water through germination and give the roots a stable surface to anchor into.

After more than 7 years of testing grow mediums on the On The Grow YouTube channel, running countless experiments with different crops, watering methods, and seed-to-harvest comparisons, we have strong opinions on what works and what doesn't. This blog ranks 10 of the most common hydroponic grow mediums for microgreens from worst to best based on our own real-world testing. If you're brand new to microgreens, our beginner's guide to growing microgreens is a great place to start before diving into medium choice.

Quick Answer: What Is the Best Hydroponic Grow Medium for Microgreens?

After 7+ years of testing, our top pick is the reusable silicone grow medium, followed by coco coir for beginners and Biostrate for single-use commercial hydroponic setups. Reusable silicone wins on cost-per-tray (rated for 20 to 30+ growing cycles), food safety (virgin food-grade platinum-cured silicone, FDA compliat, LFGB Tested & Compliant), sustainability (no single-use waste), and ease of cleaning. Coco coir is the best entry-level option because it's forgiving and beginner-friendly. Biostrate is the strongest single-use mat for commercial growers needing consistent results. Mesh trays alone work well for aggressive rooters like peas.

How We Rank Grow Mediums

Every ranking on this list is based on our own hands-on growing experience in our Texas grow space. We rank based on:

Germination consistency: Does the medium give us even germination across the whole tray, or do we get bare patches?
Water retention: Does the medium hold the right amount of moisture during the critical germination phase without going swampy?
Root development: Can the roots get through and grab the medium easily? Or do they struggle?
Harvest cleanliness: When we cut microgreens, do we end up with medium debris in the harvest? Or is it clean?
Cost per tray over time: Reusable mediums get cheaper with every grow. Single-use mediums lock in a permanent cost per tray.
Sustainability: Compostable, reusable, or single-use waste headed to landfill?

One thing to keep in mind: our grow space has its own climate, lighting, and watering rhythm. Your results may vary. We always suggest testing 2 or 3 mediums in your own setup before committing fully. If you want to see the actual side-by-side experiments, visit our video library for the full grow medium playlist.

The Ranking: 10 Hydroponic Grow Mediums for Microgreens, Worst to Best

#10. Jute Grow Mats

Jute grow mats are made from long, soft, shiny bast fiber spun into coarse, strong threads from the jute plant. The big upside is sustainability. Jute is a renewable plant fiber, several brands sell mats made from it, and a quality one will be free of fillers and binders.

The big challenge for us has been inconsistent germination. There's usually some part of the jute mat that doesn't germinate as well as the rest. We suspect this comes from uneven water retention across the mat surface, but we've never been able to fully solve it. If you've had better results, we'd love to hear about it. For us, jute lands at the bottom of the rankings.

#9. Coco Grow Mats

Coco grow mats are thickly woven coconut fibers pressed into a 10x20 mat shape. They're sustainably harvested, fit our Bootstrap Farmer 1020 trays perfectly, and have a clean look in the tray.

This is one of those mediums where it does alright, but you wish it did better. The biggest issue we ran into was poor water retention during germination, which meant we had to babysit our trays more than usual to keep them from drying out. We think coco grow mats would shine in a true hydroponic system like an Ebb and Flow or NFT setup, where water is moving constantly. In a basic tray-based microgreens grow with a humidity dome and bottom watering, it ranks low for us.

[IMAGE: side-by-side hydroponic microgreen grow mats showing hemp, coco mat, coco coir, and Biostrate for comparison]

#8. Micro Mats and Confetti

Micro Mats and the Confetti version are essentially the same product, just in two different forms. Both are made from sustainably harvested wood fibers and come in a dehydrated state. The Mat version is a pre-cut sheet sized for a 10x20 tray. The Confetti version is just the mat shredded up, and the company charges roughly $0.40 more per tray for the privilege.

The Mat version is finicky to place. Even though the sheets come pre-cut to fit a 1020 tray, the second you add water the mat ripples, becomes soggy, and tears extremely easily if you have to reposition it. We've also noticed the mat stays dense even when fully wet, which makes it harder for roots to push through. Some crops still turn out great. Others struggle to break through.

The Confetti version, despite costing more, allows roots to get through more easily. The downside is that the shredded fiber kicks up dust clouds during handling that get everywhere in the grow space. Both products land in the lower third of our rankings.

#7. Peat Moss

Peat moss is dead fibrous material formed when mosses and other organic matter decompose in peat bogs over thousands of years. That's actually the biggest knock against peat moss: it takes millennia to form, which makes it less than ideal from a sustainability standpoint compared to coco coir or hemp.

That said, peat moss is naturally sterile, which is a real plus, and it has solid water retention. You'll usually see it mixed into soil to improve drainage in heavy clay-based mixes. As a standalone microgreens medium, we've heard from plenty of growers who use it successfully. Our own testing with peat moss has been limited compared to the mediums higher up the list, so we're keeping its rank conservative for now.

#6. Vermiculite

Vermiculite is a naturally occurring hydrated magnesium iron aluminum silicate mineral. When it's heated in a furnace, it expands and takes on an accordion-like shape. People usually mix it into soils for drainage and rooting, but it can also be used standalone, similar to how perlite is used in a Dutch bucket system.

Vermiculite is technically reusable. You can wash and sterilize it, though the process is involved enough that most home growers won't bother. We don't have a ton of head-to-head testing with vermiculite as a standalone microgreens medium yet, but it's been recommended to us enough that we wanted to give it a fair spot in the rankings. If it behaves similarly to perlite (which it likely does), it could move up the list with more testing.

#5. Paper Towels

Paper towels have grown on us as a grow medium. The biggest perks are that they're cheap and available everywhere. The drawbacks are real though, and you need to manage them carefully.

First, paper towels dry out faster than most other mediums depending on the brand and ply. Second, if you over-water, the stagnant water trapped between the layers smells terrible fast. Third, brand matters a lot. 1-ply and 2-ply paper towels behave completely differently, different brands are woven differently, and some are made from different fiber blends. Most importantly, many paper towels are bleached with chlorine compounds or made from recycled paper that may contain ink, dyes, or chemical residues that are not food-safe. If you're growing food you intend to eat, you need a paper towel that's specifically labeled as unbleached and food-safe.

Some crops also struggle to push through the paper towel during germination. We've found this is largely solved by adding extra weight on top of the tray during the blackout phase. Our recommendation if you want to try paper towels: use a 2-ply unbleached food-safe brand, double-layer it in the tray, and don't over-water. Useful as a backup or a fun experiment, but not what we'd reach for daily.

#4. Perlite

Perlite is amorphous volcanic glass that occurs naturally and expands dramatically when heated. You've probably seen it as the small white pebbles mixed into commercial potting soils. In hydroponics, it's most commonly used in Dutch bucket systems for growing tomatoes because it holds water for the roots while still giving something firm to anchor into.

For microgreens, perlite holds onto water surprisingly well and spreads easily in a tray. The big downside is the dust. Perlite is extremely dusty during handling, so always wet it down lightly before working with it. We also learned the hard way that perlite works much better with a mesh 1020 tray than a slotted one. The mesh lets the roots wrap around the perlite and makes harvest much cleaner. With slotted trays, the perlite tends to fall through the slots and the roots have a harder time anchoring.

Perlite is also technically reusable. You can wash and sterilize it between grows, though it's a process most home growers will skip. Bottom line: messier than we'd like, but it gets the job done. Probably not the right choice for very small seeded crops like Red Garnet Amaranth or celosia.

#3. Hemp Grow Mats

Hemp grow mats are made from loosely woven hemp fibers. In every head-to-head test we've run on single-use grow mats, hemp consistently lands in 2nd or 3rd place, which is why it earns a spot near the top of this list. Hemp is renewable, biodegradable, and produces strong, consistent growth on almost every microgreen we've tested it with.

The main thing to watch out for is over-watering. Hemp retains water aggressively, so it's easy to push too much moisture into the mat and trigger germination issues or mold. Once you learn the right watering rhythm for hemp, the results are excellent. Brand matters here too. Terrafibre has been our preferred hemp mat brand for years, and we recommend buying it in a roll so you can cut it to size for trays of various dimensions, including the 7x14 OTG Tray Kit.

#2. Biostrate

Biostrate is a blend of biopolymers and natural fibers engineered specifically for hydroponic microgreen growing. If you've never heard of it, you're not alone. We hadn't either before our first experiments. Biostrate has won nearly every grow mat experiment we've put it through, scoring at or near the top on germination, growth speed, and final harvest weight. We rarely run into problems with Biostrate, and when we do it's almost always because we over-watered.

The trade-off is sustainability. Biostrate isn't compostable in a home setting. It can only be broken down in an industrial composting facility. That's a real turn-off for us, especially when hemp is a comparable performer that fully composts at home. Still, if you're running a commercial microgreens operation and you need consistent, repeatable results across hundreds of trays, Biostrate is hard to beat.

Tip: Both Biostrate and hemp come in large rolls that you cut to size yourself. A paper cutter is dramatically faster and cleaner than using scissors. Check our Amazon storefront for the paper cutter we use, along with our other equipment recommendations.

#1. Reusable Silicone Grow Medium

Our #1 pick is the reusable silicone grow medium, which we've been developing, refining, and using as our daily-driver medium for years. This is the medium we use for almost every microgreen we grow at On The Grow, and it's why we eventually built our own line of 10x20, 10x10, and 7x14 sizes around it.

[IMAGE: purple kohlrabi microgreens growing on a reusable silicone grow medium showing healthy canopy and root mat]

The reusable silicone grow medium is made from virgin food-grade platinum-cured silicone with a fiberglass mesh core. It's FDA compliant per 21 CFR 177.2600 and LFGB Tested & Compliant. The 1.2mm hole size standard version works for the vast majority of microgreen crops (broccoli, radish, kale, mustard, cabbage, kohlrabi, sunflower, and more), and we also offer a 1.7mm large hole version for larger seeds and aggressive rooters like peas, sunflower, and wheatgrass.

Why it ranks #1 for us:

Cost per tray drops dramatically over time. Rated for 20 to 30+ growing cycles, which works out to roughly 18 to 24 months of regular use at 2 to 4 grows per month. Compared to a single-use mat that costs $1+ per tray every grow, the savings add up fast.
Food-safe materials. Virgin food-grade platinum-cured silicone with no PFAS, no BPA, no phthalates, and no petroleum-based chemicals. Third-party tested for FDA compliance.
Easy to clean. Hand wash with food-safe dish soap, rinse, optional 2-minute boil and hydrogen peroxide sanitize between grows. Dishwasher-safe.
No medium debris in your harvest. Roots stay on the silicone, not in your final product.
Works well with bottom watering and fertilizer. Pair it with Ocean Solution 2-0-3 at 0.5 oz per gallon, pH 5.5 to 6.0, for strong growth.
Massive reduction in single-use waste. One reusable silicone medium replaces hundreds of disposable mats over its lifetime.

For a deeper dive on seed compatibility, cleaning protocols, and care, see our complete reusable silicone grow medium guide, our seed compatibility blog, and our cleaning and sanitizing guide.

Honorable Mention: Mesh Trays Alone (No Medium)

Some microgreens grow so aggressively that they don't need a medium at all. Pea microgreens are the standout example. Pea roots are powerful enough to anchor directly into the mesh of a 10x20 mesh tray with no medium underneath. This is now our preferred method for growing peas. It eliminates the medium cost entirely, makes harvest cleaner, and avoids the issue of pea roots tangling deeply into a reusable medium and being difficult to remove later. For full details, see our how to grow pea microgreens guide.

What About Coco Coir?

For years, coco coir was at the top of our rankings, especially as a beginner-friendly hydroponic medium. Coco coir is ground-up coconut husk that has a soil-like texture, holds water well, and works beautifully with bottom watering. It's still one of the best entry-level mediums for new microgreen growers because it's forgiving, easy to work with, and gives consistent germination across almost every crop we've tested.

That said, we no longer carry coco coir in our store because we've shifted our focus to reusable mediums. If you're a beginner and you want to start with coco coir, we recommend the coco coir brick we use ourselves, available on Amazon. One brick will expand to fill roughly 4 to 5 standard 10x20 trays with 6 cups each.

A few things to know about coco coir:

Quality varies a lot by source. Stick with reputable brands.
Some coco coir requires rinsing before use to flush out salt content (called "buffering"). Most of what's sold for food production today is pre-buffered and ready to use, but always check the label.
Coco coir is single-use as a microgreens medium. After harvest, it can be composted or used as a soil amendment in your outdoor garden.
It works well with plain water or with hydroponic nutrients added via bottom watering. Pair it with Ocean Solution 2-0-3 for stronger growth.

For a full breakdown of coco coir vs. reusable medium head-to-head, see our case study comparing coco coir vs. reusable silicone grow medium at high seeding density.

Quick Reference: How the 10 Mediums Compare

Rank	Medium	Reusable?	Best For
1	Reusable Silicone Grow Medium	Yes (20 to 30+ cycles)	Everyday growing, cost savings, food safety, low waste
2	Biostrate	No	Commercial single-use, consistency
3	Hemp Grow Mats	No (compostable)	Sustainable single-use option
4	Perlite	Technically	Hydroponic setups, mesh trays
5	Paper Towels	No	Cheap backup, experimenting
6	Vermiculite	Technically	Hydroponic blends, experimenting
7	Peat Moss	No	Sterile growing, soil blends
8	Micro Mats / Confetti	No	Specific crop trials
9	Coco Grow Mats	No	Active hydroponic systems
10	Jute	No (compostable)	Sustainable backup option

Coco coir falls outside this ranking because we now treat it as a separate beginner-friendly category rather than competing with the hydroponic mat options. For new growers, coco coir is still one of the best starting points.

Frequently Asked Questions

What is the easiest grow medium for microgreen beginners?

Coco coir is the most forgiving option for new growers because it holds water well, allows good root development, and gives consistent germination across nearly every crop. Once you've grown a few successful crops on coco coir, transitioning to a reusable silicone grow medium is the easiest cost-saving upgrade you can make.

Is hydroponic growing better than soil for microgreens?

Neither is universally better. Hydroponic mediums (silicone, hemp, Biostrate, coco coir) give you cleaner harvests, more control with fertilizer dosing, and faster setup turnaround between grows. Soil tends to be more forgiving for beginners, gives slightly slower but very consistent results, and requires no added fertilizer. Most experienced growers we know prefer hydroponic for daily commercial growing and use soil for specific crops or backup setups.

Can you reuse hydroponic grow mediums?

The reusable silicone grow medium is rated for 20 to 30+ growing cycles. Perlite and vermiculite are technically reusable if you wash and sterilize them, though the process is involved. Most single-use mats (hemp, Biostrate, coco mats, jute, Micro Mats) are designed for one grow cycle.

What hydroponic nutrients do you recommend for microgreens?

We use Ocean Solution 2-0-3 at 0.5 oz per gallon, pH balanced to 5.5 to 6.0. Other hydroponic-compatible water-soluble formulas like General Hydroponics MaxiGro also work well. Fertilizer is critical when growing on reusable mediums because they contain zero nutrients (silicone is completely inert), and it's also recommended on coco coir for stronger growth. Never add fertilizer to soil-based microgreen trays.

Which grow medium is most sustainable?

Long-term, the reusable silicone grow medium is the most sustainable choice because one medium replaces 20 to 30+ single-use mats. For single-use options, hemp grow mats are the most sustainable because they're renewable and compostable at home. Jute is also home-compostable. Biostrate requires industrial composting. Peat moss takes thousands of years to form, so it ranks lowest on the sustainability scale.

Do you have to use a medium to grow microgreens?

For most varieties, yes. Microgreens need something to anchor their roots into during the early growth phase. The exception is pea microgreens, which root aggressively enough to grow directly on a bare 10x20 mesh tray with no medium underneath. A handful of other aggressive rooters (like some bean varieties) can also be grown mediumless, but pea is by far the most common.

Final Thoughts

This ranking will keep evolving. We're constantly testing new mediums, retesting old ones in different conditions, and refining our process. The biggest shift in our own grow space over the last several years has been moving away from single-use mats and toward our reusable silicone grow medium for almost every crop. The cost savings, the reduction in single-use waste, and the consistency we get with food-grade silicone have all combined to make it our daily driver.

That said, every grow space is different. The best way to figure out what works for you is to test 2 or 3 mediums in your own setup and watch how they perform across multiple crops. If you want to see our head-to-head experiments, check out our video library for the full grow medium series. For a deeper dive into every step of microgreen growing, our Microgreen Masterclass covers seed-to-harvest methods, troubleshooting, crop-specific tips, and the full system we've built over 7+ years of growing.

Happy growing!

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Disclaimer: The rankings and opinions in this blog are based entirely on our personal hands-on experience growing microgreens at On The Grow over the past 7+ years in our specific grow space. Our results are influenced by our local climate, humidity, water source, lighting setup, watering habits, seed varieties, and the specific brands of each medium we tested. Your experience with any of these grow mediums may be different from ours, and a medium that performed poorly for us may work great in your setup, and vice versa.

This blog is intended for educational and informational purposes only and reflects our own opinion based on our testing. It is not a scientific comparison study, and individual results will vary. We always recommend testing 2 or 3 different mediums in your own grow space across multiple crops before committing to one as your primary growing medium.

Written by: Mandi Vaughn
Published: July 27, 2020
Updated: May 25, 2026
All content shown is Property of: On The Grow®, LLC