Large Holed - 1.7mm Silicone Reusable Grow Medium

Growing larger-seeded microgreens like sunflower, peas, or wheatgrass and want to give those aggressive root systems more breathing room? Our 1.7mm Large Holed Silicone Reusable Grow Medium offers 0.5mm more space than our standard 1.2mm version—specifically designed for crops with bigger seeds and robust root systems that benefit from extra mesh openings.

Why Choose the 1.7mm Large Hole Version?

Optimized for large seeds: The 1.7mm hole size is perfect for Black Oil Sunflower, Pea Shoots, Melon Microgreens, Radish, and Wheatgrass—crops with larger seeds and aggressive root systems that thrive with extra space. The larger openings allow roots to penetrate more easily while still providing excellent support.

Important sizing consideration: While this 1.7mm mesh can work with smaller seeds like Cabbage, Broccoli, and other Brassicas, many of these smaller seeds will fall through the holes. For the best experience with small-to-medium seeds, stick with our standard 1.2mm Silicone Reusable Grow Medium. Save this 1.7mm version for your larger-seed varieties.

Coarser texture for better grip: The 1.7mm version has a noticeably more coarse, bumpy texture compared to our smooth 1.2mm version. This texture difference isn't just cosmetic—it provides better grip for handling and makes it easy to identify which mesh size you're working with at a glance (or rather, by touch).

Same durability, different application: Like our standard silicone grow medium, this version is made from food-grade silicone with a fiberglass core for durability. It lasts for months with proper care, eliminates the need for soil or coco coir, and is fully dishwasher-safe.

Key Specifications

10x20 Size:

• Dimensions: 19.475" x 9.475"
• Hole Size: 1.7mm
• Fits: Standard 10x20 trays

10x10 Size:

• Dimensions: 9.25" x 9.25"
• Hole Size: 1.7mm
• Fits: Standard 10x10 trays

Material Features:

• Material: Food-Grade Silicone with fiberglass core
• Texture: Coarse and bumpy (vs. smooth 1.2mm version)
• Flexibility: Easily customizable with household scissors
• Lifespan: Months of continuous use with proper care

Best For These Crops:

Works with:

• Black Oil Sunflower Microgreens
• Pea Shoots
• Melon Microgreens
• Radish Microgreens
• Wheatgrass

Use Standard 1.2mm Instead:

• Broccoli, Cabbage, Kale, and other Brassicas (seeds will fall through 1.7mm holes)
• Arugula, Basil, Mustard Greens
• Any small-to-medium sized seeds

Not Recommended:

• Swiss Chard, Beets, Cilantro (these perform better in soil regardless of mesh size)
• Amaranth, fine Mustard seeds, and other very small seeds

How to Tell the Difference: 1.2mm vs 1.7mm

The 0.5mm difference is subtle visually, but there's an easy way to identify which version you have:

• 1.2mm (Standard): Smooth to the touch, feels even and consistent
• 1.7mm (Large Hole): Coarse and bumpy texture, noticeably rougher feel

Without precision measuring tools, texture is your best identifier. Just run your hand over the surface—if it feels bumpy and coarse, you've got the 1.7mm version.

Care & Maintenance

Cleaning: After harvest, use our Microgreen Medium Scraper/Cleaning Tool to remove root residue. Wash with warm water and a free-and-clear dish soap (or another silicone-safe, food-safe soap). The flexible silicone surface makes root removal quick and easy.

Sanitization between grows: For thorough sanitation, carefully pour boiling water over the mat or submerge it for 1–2 minutes. Allow to air dry fully before reuse. Sanitize after every grow.

Time investment: 5 minutes per mat from cleanup to sanitized and ready for the next grow. Many people wash and sanitize them in batches for faster timing.

For detailed cleaning protocols and troubleshooting stains, see our complete silicone maintenance guide.

Compatible Tray Systems

10x20 version works perfectly with:

• Bootstrap Farmer 10x20 Heavy Duty Trays
• Any standard 10x20 microgreen tray system

10x10 version works perfectly with:

• Bootstrap Farmer 10x10 Heavy Duty Trays
• Standard 10x10 Growing Trays
• Any standard 10x10 tray system

1-Year Warranty

All silicone mesh screens are backed by our 1-year warranty. Grow with confidence knowing you're covered.

Important Product Disclaimers

• Please review our Reusable Grow Medium Safety Disclaimer before purchasing
• Trays, seeds, and other items shown in photos are NOT included
• Hole size difference: Only 0.5mm larger than standard 1.2mm—visually subtle but functionally significant for large seeds
• Texture identifier: 1.7mm version feels coarse and bumpy; 1.2mm version feels smooth
• This 1.7mm is made differently than the material for our 1.2mm. The 1.2mm has been LFGB tested & certified, whereas the 1.7mm has not.
• Small seed warning: Brassicas and other small-to-medium seeds will fall through these holes—use our 1.2mm standard version instead
• Silicone staining: Some seed varieties may cause natural staining on the silicone surface—this doesn't affect performance
• Fiberglass core: Replace your mat if you notice tears, deep cuts, or significant wear that could compromise the fiberglass core integrity. Learn more about replacement timing
• Not recommended for: Swiss Chard, Beets, Cilantro (these perform better in traditional soil-based methods)
• NUTRITIONAL CONTENT DISCLAIMER: This product is an inert growing medium that does not add or remove nutrients from your crops. We make NO claims about nutritional content or nutrient density of microgreens grown using this product. Nutrient density depends on many factors outside our control including seed variety, water quality, light, fertilizers, and growing conditions - not the growing medium itself. We have not conducted laboratory testing and are not nutritionists. For complete nutritional disclaimer, see: [link to Safety Disclaimer page]

Optimized for large seeds and aggressive root systems—give your sunflower, pea, and wheatgrass crops the extra space they need to thrive.