Grow Mediums

Silicone Reusable Microgreen Grow Medium - Complete Grow Medium Overview

Meet our NEW Reusable Microgreen Grow Medium: Silicone

A reusable grow medium, as the name suggests, is a medium that can be used multiple times for growing plants. This approach is not only cost-effective but also can be more environmentally friendly. It greatly reduces the need for single-use grow mediums like soil or coco coir, or even other Hydroponic Grow Mats, which often come wrapped in plastic and require large quantities for each Microgreen grow.

Purple Kohlrabi Microgreens growing on Silicone Reusable Grow Medium

You could compost your coco coir or soil after growing microgreens on it and reuse it again, but the sterilization and composting process can be quite tedious when compared to simply cleaning off & sterilizing the steel mesh or silicone medium and starting again. Not to mention, if you don't sterilize the reused compost or coco coir properly, you risk the potential for pathogens that could take over your crops.

What these reusable grow mediums do, is act as lattice for the plant seeds to sit on top of and eventually act as anchors for the root structures that develop from the plants. And if you are a fan of our Stainless-Steel Reusable Grow Medium, you may find yourself loving our newest product, the Silicone Reusable Grow Medium. In this blog we'll cover our Silicone Reusable Grow Medium more in depth, starting with costs and environmental impact.

Initial Investment vs. Long-Term Savings

Cost Factor

Reusable Grow Medium (10-pack)

Coco Coir Brick (1.4lb)

Initial Cost (avg.)

$60

$10

Durability / Usability

Can be used repeatedly until wear down

Single use per portion

Yield per Unit

10 sheets (each equals a 1020 tray)

7 1020 worth trays per brick (6 cups each)

Cost per Tray

$6 per tray (initially)

$1.43 per tray

Cost per Tray per Cycle

$0.30 per tray (if used for 20 cycles)

Not applicable

Long-Term Cost Efficiency

More cost-efficient over many cycles

Less cost-efficient, requires continuous purchase

Environmental Impact

Less waste due to reusability

More waste due to consumable nature

Notes:

  • The cost per tray per cycle in this table for the reusable grow medium assumes each sheet is used for 20 cycles and that you are using 10x20 trays & 10x20 silicone. This number can vary based on the actual amount of use you get out of the sheets before needing to replace.
  • The coco coir brick, being a consumable, does not have a cost per cycle as each portion is used once, then composted after harvest.
  • The cost and amount used for Coco Coir in this table is based off of using 1"inch deep 10x20 sized trays with 6 cups per tray.
  • The long-term cost efficiency and environmental impact are based on the assumption of frequent and long-term use.

Environmental Impact and Indirect Savings

Reduced Environmental Footprint

  • Waste Reduction: By minimizing the need for disposable grow mediums, the silicone medium contributes to less waste production, which can not only be environmentally responsible but could also lead to indirect savings in waste management.
  • Sustainable Practices: Adopting sustainable practices can enhance the brand image and appeal to environmentally conscious consumers, potentially increasing market share and revenue.

PFSA's and Food-Grade Silicone

Microgreen Seeds Germinating On Silicone Reusable Grow Medium

Food-grade silicone, widely used in kitchenware and containers, is generally considered safe and does not contain per- and polyfluoroalkyl substances (PFAS). PFAS are a group of man-made chemicals that include PFOA, PFOS, GenX, and many other chemicals. These substances are known for their use in various industrial applications and consumer products for their water and oil repellency properties.

Silicone, a synthetic rubber made from bonded silicon (a natural element) and oxygen, is different from plastic and does not contain the same chemical compounds found in plastics like PFAS. It's valued for its high heat resistance and inertness, meaning it does not react with or leach into food, making it a safer choice for food contact applications.

The Silicone Reusable Grow Medium

Our silicone reusable grow medium is a step up for most people from our previous stainless-steel version, offering several advantages.

Key Features:

  • Material: Made from food-grade silicone.
  • Durability: Designed to last for years with proper care.
  • Hole Density: 1.2mm, suitable for most microgreen seeds.
  • Sizes: Available in various pre-cut sizes (10x20, 10x10, large and small sprouting tray sizes).
  • Packs: each size option comes in 2 or 10 packs

We now also offer a Silicone with slightly larger holes for larger seed varieties

  • Material: Made from food-grade silicone.
  • Durability: Designed to last for years with proper care.
  • Hole Density: 1.7mm, suitable for large seed varieties such as Sunflower, Peas, Wheatgrass, Radish and Melon.
  • Sizes: Available in various pre-cut sizes (10x20 or 10x10 tray sizes).
  • Packs: each size option comes in 2 or 10 packs
    Available here: Click or tap

Advantages Over Stainless Steel Medium

While the stainless steel medium was well-received, it had some limitations, such as difficulty in reshaping and sharp edges. The silicone medium addresses these issues with its flexibility and user-friendly design.

Pros:

  • Easy to handle and cut to custom sizes.
  • Simple to flatten and set up.
  • Excellent seeding visibility.
  • Easy to clean and sanitize for reuse.
  • Effective for most microgreen seeds.
  • Pays for itself after a couple uses.
  • Keeps grow-space cleaner from soil & coco coir debris

Cons:

  • Higher initial investment compared to soil.
  • Moisture retention can be challenging, at first.
  • Small seeds like sorrel and amaranth may fall through.
  • Silicone Medium can develop stains with some seed varieties like alfalfa.

Usage and Maintenance

Broccoli Microgreen Roots On Silicone Reusable Grow Medium

Using the silicone medium is straightforward, and lower in this blog we have video resources linked to guide you on how to grow microgreens with our silicone reusable grow medium.

Regarding the cleaning and sanitation process, after you've removed all the roots from the silicone grow medium, there are several methods you can employ. Begin by washing the silicone with a combination of food-safe soap and lukewarm to hot water, using your hands to gently lather and rinse. Alternatively, create a cleaning paste using a mixture of 1/4 cup baking soda and warm water. Submerge the silicone in this paste for about 5 minutes, then rinse thoroughly. This also helps with stain removal.

For additional sanitation, consider the following natural and silicone-friendly options:

  1. Fill a sink with hot water and dish soap, and let the silicone soak for approximately 20 minutes.
  2. Boil the silicone in water for 2 to 3 minutes. (handle at your own caution)
  3. Prepare a solution of equal parts food-grade hydrogen peroxide and water, and soak the silicone for 5 minutes up to 24 hours.

The best Silicone Safe & Food Safe soaps to use are Dr. Bonner's Pure Castile Soap, or Seventh Generation Free & Clear Dish Liquid.

It's important to only use Silicone safe cleaning and sanitation practices, and to avoid using abrasive scrubbers like scouring pads, as they can damage the silicone surface or create tiny cuts where bacteria can accumulate.

WATCH FULL VIDEO HERE ON OUR CLEANING PROCESS

When to replace:

While this medium is Reusable, it eventually will have to be replaced, and the frequency of when really depends on how you take care of the medium. For instance, we have been using the same Silicone sheets for about 9 months now, with repeated use monthly, and haven't had to replace ours, yet. However, here are the important signs to look for.

Replace your food-grade silicone mesh when you notice any of the following signs:

  1. Physical Damage: Look for tears, deep cuts, or significant wear that could compromise its integrity.
  2. Loss of Flexibility: Silicone that becomes stiff or loses its flexibility can affect performance.
  3. Surface Degradation: If the surface becomes sticky, discolored, or begins to degrade, it's no longer suitable for use.

Harvesting Microgreens

Harvesting is simple and can be done by gently pulling the microgreens by hands, roots and all, or using a harvesting knife. Be careful not to cut the silicone during the process.

How it arrives to you

Typically, when you order our Silicone Reusable Grow Medium from our shop, it will arrive rolled up and tied with a simple bow, unless you order 1020 trays or our Stainless-Steel Reusable Grow Medium with your order. In this case, it arrives flat packed. Luckily, with the silicone, as previously mentioned, unrolling the medium is quick and easy.

How to Grow Microgreens using our Silicone Reusable Grow Medium

Let's explore how to cultivate microgreens using our Silicone Reusable Microgreen Grow Medium, but first, it's important to understand which seeds are compatible with this medium, as this is a frequently asked question.

Compatible Seeds:

  • Ideal for Silicone Medium: Black Oil Sunflower, Pea, Radish, Broccoli, Arugula, Basil, Cabbage, and Kohlrabi Microgreens. And most seeds in the brassica family.

Less Compatible Seeds:

  • Challenges with Silicone Medium: Swiss Chard, Beets, and Cilantro Microgreens, due to their unique germination requirements.
  • Small seeds such as Amaranth and Mustard may pose challenges, as they tend to slip through the mesh holes.

    Adapting to the Silicone Reusable Grow Medium can be a bit of a learning curve, especially for those accustomed to using Soil & Coco Coir. This is mainly because of the differences in water retention between reusable and traditional mediums. However, once you get adjusted, it's quite straightforward. To assist you in this learning process, we have an entire YouTube Playlist that is dedicated specifically to the Silicone Reusable Grow Medium.

    YouTube Playlist: Silicone Reusable Grow Medium
    This playlist features a range of instructional videos on cultivating various microgreens, including Sunflower, Peas, and Wheatgrass, among others. Additionally, it includes comparative experiments between the Silicone Reusable Grow Medium and other types of mediums like Coco Coir, Soil & our Stainless-Steel Reusable Grow Medium. You'll also find useful tips and tricks, with more content scheduled to be added soon!

    More resources will also be available via our Tik Tok & Instagram Reels feed. Be sure to follow us to stay updated. Nowadays, most all of our grow kits come with our Silicone Reusable Grow Mediums.

    Common Questions

    Isn’t it hard to remove the Microgreen roots from this grow medium?

    Surprisingly, it’s really quick, in fact it takes us about 30-seconds to 1 minute (depending on our movement speed) to remove leftover roots & stems from the harvested mat using our tool. You can either use this magical tool we sell, as seen above, or simply use your hands and gently wipe everything off. Sometimes you’ll have a little bit of debris left over after using the tool or your hands, but if you run some water over the medium and use your hands to lather it, everything should come off very quickly!

    Do I have to use nutrients when growing using this medium?

    Technically, no. Regular tap water would still work great, for instance, in this video, we grew without any additional nutrients and got great results. However, we are pro-fertilizer and recommend adding additional fertilizers like our favorite Ocean Solution 2-0-3 to your grows. Fertilizers can enhance growth and generally yield harvest weights that are on par with those achieved using Soil and Coco Coir.

    Is mold or pests an issue with this medium?

    Similar to other microgreen growing mediums, the risk of pests, mold and other pathogens exists with the Silicone Reusable Microgreen Grow Medium, often due to decaying seeds or health issues in your crops. However, this silicone medium offers a distinct advantage over many others when it comes to mold & pathogens. Once your crops have established their roots in the medium, you can easily use a spray nozzle to gently wash away any decaying seed hulls on the tray. Additionally, to prevent mold, which is a common practice with mediums like coco coir or soil, you can target specific areas with a hydrogen peroxide (H2O2) solution or a standard garden anti-fungal spray. At the end of the day, you are dealing with living organisms, and sometimes mold, pests & pathogens happen.

    Is there a way for me to cut mine to a different size?

    Should your Silicone grow medium be slightly larger than needed, or if you require a size that isn't available, you can conveniently trim it to your desired dimensions using a regular pair of scissors at home. Please be aware, though, that once the medium is cut, it is altered from its original state and therefore becomes ineligible for return to us.

    How to store your Reusable Microgreen Grow Medium

    To prevent your Silicone Reusable Microgreen Grow Medium from developing creases or folds, it's best to store them in a flat position. Using an additional tray, either 10x20 or 10x10 in size, specifically for storage purposes is ideal.

    Where do you ship currently?

    Currently we only ship this product in the US and Canada through our website. We have a 1 Year Warranty on all Mesh Screens! 😊

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    We've tried to cover all the essentials about our Silicone Reusable Microgreen Grow Medium, but if there's anything we've overlooked, please feel free to point it out, and we'll be sure to include it! Our goal is to ensure you have the best experience with OTG products. We genuinely care about our community and are committed to simplifying the process of growing and managing microgreens. That's why we've developed the patent-pending "Microgreen Tray Clips," designed to make bottom watering of your microgreen crops quicker and more efficient.

    Stay tuned for more exciting updates and offerings on our site. Don't forget to subscribe to our email list for early access to new products, exclusive information, flash sales, and more – even before we announce them to our larger social media audience!

    We hope to make you a be-leafer if you aren’t already!

    -CJ & Mandi

    Written by: Mandi Warbington
    Edited by: CJ Vaughn
    Published: May 26, 2023

    All content shown is Property: of On The Grow®, LLC

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    2 comments

    Christine Tenhave

    Christine Tenhave

    Hi C.J. and Mandi,
    I really enjoy watching your you tubes! I am just starting out on growing microgreens. I have an avenue to sell them also :)
    I would like to purchase some of your equiptment. However, you mentioned that you only can ship to the USA and Canade. When do you think we can get some here in Australia?
    I like the idea of a non soil growing medium. Today, I watched your stainless steel presentation, including the new clip. It looks great!
    *a question: I did watch a you tube earlier on growing with coco coir and soil. Mandi, I think you liked the microgreens grown in the soil, as opposed to coco coir. They were more flavoursome. I am hoping to sell great tasting microgreens to a restaurant. I think the reusable growing medium and nutrients will be great to use, WIll the taste still be great?
    ALso, is there “a taste” at all by using the stainless steelor silicone?
    ( I’d appreciate it if you don’t publish this please :) )
    Cheers, Christine

    Jon

    Jon

    Any thoughts or recommendations on flood tray microgreen watering systems with these silicon reusable media? Wondering if this would work or not since there’d be intervals of no water under the tray. Maybe I’d just have to run the pumps on a much higher frequency? Just wanted to know if you had any thoughts on this or experience using the reusables with a flood and drain setup.

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