Retrofitting Polytunnels: Optimizing Mushroom Greenhouses with Modular Wire Shelving

For many producers, the journey into commercial fungi cultivation starts in a High Tunnel or Polytunnel. These structures are cost-effective to erect ($10-$15 per sq. ft.), but they come with a major hidden flaw: Climate Uniformity.

In a 30-meter long plastic tunnel, maintaining consistent humidity and CO2 levels from one end to the other is notoriously difficult. If you are stacking substrate bags on the ground or using improvised wooden tiers, you are likely creating "dead zones" where air stagnates, leading to mold issues and uneven crop maturation.

Upgrading to a professional Wire Shelving System is not just about holding more bags; it is the most effective way to fix your tunnel's airflow dynamics without buying expensive HVAC ducting.

In a tunnel environment, the biggest challenge is pushing air through the biomass. Solid walls of stacked bags block cross-ventilation. This results in the "center-row syndrome," where mushrooms in the middle of the block suffocate from high CO2, while the outer rows dry out.

The Mesh Mushroom Rack solves this by suspending each bag individually in free space.

Figure 1: The open grid structure allows fans to push air effectively through the entire length of the tunnel.

Because the rack structure is >95% open space, it offers almost zero static resistance to your ventilation fans. Fresh, humidified air can permeate the core of the growing block. This ensures that a Shiitake log at the back of the tunnel receives the same oxygen levels as one at the front, leading to a uniform harvest window.

Seasonal flexibility is key for greenhouse growers. You might grow "Shiitake" on synthetic "Substrate Logs" in the winter and switch to "Warm-weather Oyster" varieties in the summer.

Rigid, fixed shelving often limits you to one bag type. Our modular grid system offers Universal Compatibility:

Unlike indoor factories with polished concrete floors, greenhouses often have uneven dirt or gravel floors. Traditional rigid shelving requires a perfectly level foundation to avoid tipping over.

We engineer our systems with Adjustable Levelling Feet and wider base plates specifically for Uneven Terrain. This allows you to install a stable, vertical wall of mushrooms directly onto compacted soil or gravel without the expense of pouring a concrete slab.

Figure 2: Wide base plates ensure stability even on non-concrete greenhouse floors.

Upgrading a 150m² tunnel: Ground Stacking vs. Vertical Retrofit.

For the "Producers" supplying local markets, the goal is consistency. Retrofitting your tunnels with proper racking turns a weather-dependent farming operation into a controlled manufacturing process.

No. Greenhouses are notoriously corrosive due to the cycle of condensation. Our Fluidized Bed Dipping creates a hermetic seal around the steel. Unlike paint, which peels when wet, our coating is chemically bonded to survive constant dripping and 95%+ relative humidity. 2. Can I move the racks if I relocate my tunnel?

Yes. This is a major advantage for tenants leasing land. The system is 100% bolt-free and modular. You can dismantle a fully outfitted tunnel in one day and transport the racks to a new site without losing your investment. 3. Do you offer layouts for arched tunnel walls?

Absolutely. We can provide a "stepped" layout design. By using shorter racks on the sides and taller racks in the center (the apex), we maximize the use of the tunnel's curved volume, which is often wasted space with standard square shelving. 4. How much weight can a single grid layer hold?

Each individual grid cell is engineered to support typical commercial substrate weights (up to 8kg per bag). For Shiitake logs laid horizontally, the load is distributed across the mesh, easily supporting high-density heavy logs.5. Is this suitable for 'Horeca' suppliers requiring premium aesthetics?

Yes. Suppliers to the Horeca (Hotel/Restaurant) sector need pristine mushrooms. By elevating the crop off the muddy ground and ensuring 360-degree airflow, the racks prevent "water-blotch" and dirt splash, ensuring your product is clean and premium-grade upon harvest.