What Makes an ECB Biodegradable?

A biodegradable erosion control blanket is one whose materials break down through natural microbial processes after the product has served its purpose. Most ECBs use natural fiber bodies — wood excelsior, straw, or coir — that are inherently biodegradable. The variation is in the netting:

• Photodegradable polypropylene netting: Breaks down under UV light but is not biodegradable in the soil and leaves synthetic residue behind. Most standard ECBs — including netted Curlex products — use this type. A natural fiber body with photodegradable netting is not a fully biodegradable product.
• 100% net-free construction: Curlex NetFree eliminates netting entirely — the blanket is stitched together with biodegradable thread, leaving absolutely zero synthetic residue. This is the only truly "100% biodegradable" construction available in an ECB.

This distinction matters. When a specification says "biodegradable ECB," it usually refers only to the fiber body being natural — the netting may still be synthetic. When a specification requires "100% biodegradable" materials or prohibits synthetic netting residue, the only product that qualifies is a net-free blanket like Curlex NetFree.

Why Choose Biodegradable?

Bio-based ECBs offer meaningful advantages for most erosion control and revegetation projects:

No Removal Cost

The natural fiber body degrades in place. There is no labor cost for removal, no disposal logistics, and no risk of damaging established vegetation during removal. On large highway or land development projects, this alone makes natural fiber ECBs significantly more economical over the full project lifecycle. (Note: products with photodegradable netting can still leave synthetic net residue behind even after the fiber degrades.)

Soil Improvement

As the fiber breaks down, it incorporates organic matter directly into the topsoil. This is especially valuable on cut-and-fill slopes where topsoil has been stripped or disturbed — the organic input from a degrading ECB measurably improves soil structure and moisture retention in the years after installation.

Environmental Compatibility

Fully biodegradable, net-free products leave no synthetic debris in the landscape. This matters particularly in sensitive environments: riparian corridors, wildlife habitat areas, organic farms, and any site where plastic persistence in the soil is a concern.

Better Germination Conditions

Natural fibers create an environment that is conducive to seed germination. Wood fiber retains moisture longer than synthetic fiber, moderates soil temperature more effectively, and creates a microclimate at the soil surface that supports seedling establishment. The result is typically better germination rates and faster establishment compared to bare seeding.

Decomposition Timeline

The decomposition rate of a natural fiber ECB depends on moisture, temperature, microbial activity, and the specific fiber used:

• Wood fiber (Curlex): Visible degradation typically begins within the first growing season. Most of the mat has broken down by the end of the second season. In warm, wet climates, degradation can be faster; in cold, dry conditions, it may extend somewhat longer.
• Straw fiber: Generally degrades faster than wood fiber — often within a single growing season.
• Coir fiber: Degrades more slowly, typically over two to five years. Coir is used where a longer protection period is needed before vegetation is fully established.

Biodegradable vs. Synthetic ECBs

For temporary vegetation establishment on slopes and channels, natural fiber ECBs are almost always the better choice. Here is a direct comparison:

• Germination performance: Natural fibers outperform synthetic fibers for moisture retention and microclimate creation at the soil surface.
• End-of-life cost: Natural fiber bodies require no removal; synthetic ECBs must be removed and disposed of. (Products with photodegradable netting may still leave synthetic net residue.)
• Environmental impact: Fully biodegradable, net-free ECBs return organic matter to the soil and leave no plastic residue; synthetic ECBs leave plastic residue unless removed.
• Regulatory acceptance: Many state DOT and environmental permit specifications require biodegradable ECBs — and some require 100% biodegradable, net-free products, particularly near waterways.
• Long-term protection: For permanent reinforcement where vegetation alone is insufficient, a synthetic TRM is required — not a synthetic ECB. ECBs are temporary products by definition.

Fully Biodegradable: The NetFree Difference

There is a meaningful distinction between a natural fiber ECB (natural fiber body with polypropylene netting) and a 100% biodegradable ECB with no netting at all. Curlex NetFree takes the most complete approach: it eliminates netting entirely, using only Great Lakes Aspen excelsior stitched with biodegradable thread. It is the only product covered in this guide that is fully, 100% biodegradable.

Curlex NetFree — 100% Biodegradable, Net-Free ECB

Curlex NetFree is the erosion control industry's first ECB that uses no netting material whatsoever. Made from naturally seed-free Great Lakes Aspen excelsior stitched with biodegradable thread, it leaves absolutely no synthetic residue in the soil — and eliminates wildlife entrapment, mowing snags, and netting cleanup entirely.

Available in 8′ × 90′ rolls (~720 SF per roll). Suitable for slopes up to 3H:1V.

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Curlex NetFree is specified for projects where synthetic netting residue is prohibited or undesirable:

• Projects with environmental permit conditions requiring 100% biodegradable materials
• Sites adjacent to or within waterways, wetlands, and floodplains
• Wildlife habitat areas and conservation projects where netting entrapment is a concern
• Parks, golf courses, and residential slopes where mowing through established vegetation is required
• Organic farm operations and food-adjacent land
• Projects managed by agencies with policies against synthetic ground cover residue

Regulatory & Compliance Uses

Biodegradable ECBs are woven into the regulatory framework for erosion control in many jurisdictions:

• SWPPP requirements: Many Stormwater Pollution Prevention Plans call for biodegradable or natural fiber ECBs as an accepted stabilization measure for disturbed slopes.
• State DOT specifications: Numerous state transportation departments specify Curlex ECBs by name or require products meeting equivalent performance class standards for highway project TESC work.
• Wetland and waterway permits: Environmental permits for projects near waterways often require that erosion control materials near the water be fully biodegradable — meaning a net-free product — to prevent plastic introduction to aquatic systems.
• NPDES compliance: Under the Clean Water Act, construction sites over one acre require SWPPP compliance; biodegradable ECBs are among the accepted stabilization measures.

Always consult your project permit conditions and applicable state and local specifications to confirm which biodegradability standard is required for your specific project.

Curlex: Wood Fiber Performance

Curlex ECBs are manufactured by American Excelsior Company using Great Lakes Aspen excelsior — the same long-strand, curled wood fiber that has made wood fiber ECBs the industry standard for decades. What makes Aspen excelsior particularly effective as an ECB fiber:

• Long fiber length: Curled strands interlock to form a resilient, coherent mat that stays together during installation and storm events.
• High loft: The curled structure creates air pockets that insulate seed and moderate soil temperature.
• Excellent absorbency: Wood fiber holds significantly more water by weight than synthetic fiber, improving soil moisture retention.
• Natural origin: As a byproduct of the wood products industry, Aspen excelsior is a renewable, responsibly sourced material.

Fully Biodegradable ECB Product

Curlex NetFree is the only fully, 100% biodegradable ECB — with no synthetic netting of any kind:

Curlex NetFree — 8′ × 90′

100% biodegradable with zero netting — no plastic, no jute, nothing. Eliminates wildlife entrapment, mowing snags, and synthetic residue. The industry's first truly net-free ECB.

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Frequently Asked Questions

What makes an erosion control blanket biodegradable?

A biodegradable erosion control blanket uses natural fiber — wood excelsior, straw, or coir — that breaks down through microbial activity. The key variable is the netting: standard ECBs use polypropylene netting (photodegradable, not biodegradable), while 100% biodegradable ECBs like Curlex NetFree eliminate netting entirely, using only biodegradable stitching that degrades completely along with the mat. Only a net-free product is fully biodegradable.

How long does a biodegradable erosion control blanket take to decompose?

Wood fiber typically begins visibly degrading within the first growing season and fully breaks down within one to two years. Net-free Curlex NetFree degrades at a similar rate and leaves no synthetic residue of any kind in the soil. Products with photodegradable netting leave synthetic net material behind even after the fiber breaks down.

Are biodegradable ECBs as effective as synthetic ones?

Yes — for temporary slope and channel protection, natural fiber ECBs like Curlex perform comparably to synthetic options and often provide better germination conditions. For permanent reinforcement, a synthetic TRM is required.

What is the difference between netted Curlex and Curlex NetFree?

Both use Great Lakes Aspen wood fiber for the mat body. The key difference is the netting: standard Curlex products use photodegradable polypropylene netting to hold the mat together, while Curlex NetFree uses no netting at all — only biodegradable stitching. This means NetFree is the only fully biodegradable option, leaving zero synthetic material in the soil and eliminating concerns about wildlife entrapment or netting tangling in mowing equipment.

When are biodegradable ECBs required by regulation?

Many state and local regulations, SWPPP requirements, and environmental permits specify biodegradable or fully biodegradable ECBs for projects near waterways, wetlands, wildlife habitat areas, and certain sensitive ecosystems. Where 100% biodegradable materials are required, a net-free product like Curlex NetFree is needed. Always verify your project permit conditions.

Do biodegradable ECBs need to be removed after vegetation establishes?

The natural fiber body degrades in place as vegetation matures, eliminating fiber removal labor and disposal cost. Fully net-free products like Curlex NetFree leave nothing behind; products with photodegradable netting may leave synthetic net residue. The decomposed fiber adds organic matter to the soil, benefiting long-term site health.

Can biodegradable erosion control blankets be used near waterways?

Yes — fully biodegradable ECBs are preferred near waterways. Curlex NetFree is particularly appropriate for streambank stabilization, riparian buffer plantings, and any project where synthetic material could affect a waterbody or pose a risk to aquatic wildlife.