While straw erosion control blankets have been the industry standard for decades, in recent years, stronger alternatives like Curlex®—a proprietary curled wood fiber mat made by American Excelsior Company—have gained traction for their natural performance advantages.
Not only do Curlex fibers have a higher Manning’s N (i.e., better erosion resistance), but they are also biodegradable and more durable than standard products like straw. For this reason, Curlex is an excellent product for protecting exposed slopes, ditches, and low-flow channels from erosion.
Of course, straw still has its advantages, especially regarding price and availability.
So, how does Curlex stack up against traditional straw? Which one makes more sense for your application? In this article, we’ll break down the pros, cons, and key differences between Curlex and straw erosion control blankets so you can make a wise, data-backed choice.
What Is Curlex?
Curlex is a patented erosion control product made from Great Lakes aspen excelsior: wood fibers curled during processing and interlocked to form a dense, fibrous matrix. Unlike straw, Curlex blankets are known for their ability to conform naturally to the ground and stay in place without needing excessive staking or reinforcement.
Curlex is biodegradable, photodegradable, and designed to hold moisture, promote seed germination, and reduce sediment runoff on slopes, channels, and disturbed soils.
What Is a Straw Blanket?
Straw erosion control blankets typically comprise agricultural straw (such as wheat or barley) stitched together between two layers of biodegradable netting. These blankets are designed to retain moisture, reduce raindrop impact, and temporarily stabilize soil while vegetation takes hold.
Straw blankets are widely used because they are readily available, cost-effective, and familiar to contractors and agencies alike. However, their performance can be limited by their installation and durability under field conditions.
Curlex vs. Straw: Key Comparison Factors
| Factor | Straw Blanket | Curlex® (Excelsior) |
|---|---|---|
| Ground Contact | May tent or float over uneven terrain, requiring more staking | Naturally conforms to soil contours, excellent ground contact |
| Wind & Rain Resistance | Lightweight; prone to blowouts or washouts if not staked properly | Dense fiber structure resists displacement in wind and heavy rain |
| Moisture Retention | Moderate; dries out quickly if not installed correctly | High water retention (up to 250% of its weight); ideal for seed germination |
| Seed Germination Support | Can be uneven due to poor soil contact | Strong germination support through superior microclimate and soil contact |
| Durability | Degrades quickly; prone to breakdown in harsh conditions | Lasts 90–120 days while maintaining structural integrity |
| Wildlife Safety | May include synthetic netting that can trap animals | Available with biodegradable or photodegradable netting for wildlife-friendly use |
| Performance on Slopes/Channels | Performs adequately on flat or mild slopes | Excels on slopes, ditches, and low-flow channels due to erosion resistance |
| Environmental Impact | May contain plastic netting; agricultural byproduct | Made from renewable aspen wood fibers; fully biodegradable |
| Ease of Installation | May require trenching and heavy staking | Easier to install; minimal trenching/staking needed |
| Initial Cost | Lower upfront cost; widely available | Slightly higher cost, but often offset by lower labor and maintenance |
1. Ground Contact and Conformability
Curlex Advantage: Curlex’s curled wood fibers are engineered to spring open and interlock naturally with the soil surface. This helps the mat stay tight to the ground, even on rough or uneven terrain without floating, lifting, or creating voids underneath.
Straw Limitation: Straw blankets tend to “tent” or bridge over uneven ground, leaving air pockets that can allow water to tunnel beneath the blanket and accelerate erosion. This often requires heavier staking or trenching to compensate.
2. Performance in Wet or Windy Conditions
Curlex Advantage: Thanks to its weight and dense fiber matrix, Curlex blankets resist wind displacement without needing heavy-duty staples. They also absorb and retain water effectively, helping to moderate soil temperature and improve seed germination during dry spells.
Straw Limitation: Straw blankets are lightweight and prone to blowouts in high-wind areas unless pinned tightly. In wet conditions, they can shift, rot prematurely, or become hydrophobic if not properly anchored.
3. Moisture Retention and Vegetation Support
Curlex Advantage: Curlex retains up to 250% of its weight in water and maintains close soil contact, creating an ideal microclimate for seed germination. It helps regulate temperature and moisture during the critical establishment phase.
Straw Limitation: Straw can retain moisture, but may dry out more quickly. Seed-to-soil contact can be compromised if not securely installed, reducing germination rates and long-term vegetation success.
4. Durability and Degradation Timeline
Curlex Advantage: Curlex blankets naturally degrade in 90 to 120 days, depending on site conditions, without leaving synthetic netting or persistent residue behind. They hold their form throughout vegetation establishment.
Straw Limitation: Straw blankets can break down faster under UV exposure or wash out in heavy rain. Some products include plastic or synthetic netting, which can entangle wildlife and persist in the environment long after the straw is gone.
5. Slope and Channel Suitability
Curlex Advantage: Curlex excels on slopes and in low-flow channels. Its natural interlocking fibers resist shear stress and protect soil even under mild water flow, making it ideal for roadside embankments, culverts, and ditches.
Straw Limitation: Straw performs reasonably well on flat or gentle slopes but may struggle to stay put on steep grades or in areas with concentrated runoff unless reinforced with higher-grade netting or coir products.
6. Cost and Availability
Straw Advantage: Straw blankets are widely available at landscape suppliers and typically come at a lower initial cost, especially for large-scale applications with limited budgets.
Curlex Limitation: Curlex products are priced slightly higher and may not be as readily available in all regions. However, the total installed cost may be competitive when factoring in reduced staking, labor, and rework.
7. Environmental Impact
Curlex Advantage: Curlex is manufactured from sustainably harvested aspen wood fibers and is fully biodegradable, breaking down naturally without leaving behind harmful residue. This makes it a smart choice for LEED-compliant or environmentally sensitive projects where sustainability is a priority.
Straw Limitation: While straw is an agricultural byproduct and also biodegradable, many straw blankets contain plastic or synthetic netting that can persist in the environment long after the straw has decomposed. This limits their appeal for green infrastructure or low-impact designs.
8. Installation Labor
Curlex Advantage: One of Curlex’s most practical benefits is its ease of installation. The material conforms naturally to uneven surfaces, which reduces the need for trenching, staking, or repositioning during setup. That means fewer labor hours and a more efficient installation process, especially on large or complex sites.
Straw Limitation: Straw blankets often require additional anchoring to maintain soil contact, particularly on uneven ground. This can increase the need for trenching and rework, driving up both time and labor costs.
9. Wildlife and Aesthetic Impact
Curlex Advantage: Curlex excels in natural settings where wildlife protection is a concern. Its biodegradable fiber structure and optional photodegradable netting minimize risk to birds, small mammals, and reptiles. Over time, the material blends into the landscape as it breaks down, leaving no visual or physical trace.
Straw Limitation: Many straw blankets are made with plastic netting, which has been shown to entangle or injure animals during the breakdown period. This can pose an environmental and aesthetic concern in sensitive habitats or high-visibility areas.
Which Should You Choose for Erosion Control?
Generally, Curlex will provide a superior option for any project requiring ground protection against erosion. For example, we strongly recommend deploying Curlex if:
- You’re working on slopes, ditches, or uneven terrain
- You want higher germination rates and moisture retention
- Wildlife safety and full biodegradability are top concerns
- You’re in a high-wind or high-rainfall region
- You want to reduce rework and improve first-time installation success
Straw blankets may also be suitable for lighter or shorter-term projects that do not require as aggressive of protection. If you’re unsure which erosion control product you require, contact a stormwater and environmental consultant for more help with product selection, installation, and inspection.
FAQs
Is Curlex more expensive than straw?
Yes, typically Curlex has a higher upfront cost than straw, but it can save money on labor, installation, and rework, making it more cost-effective over the project’s life.
How long does Curlex last?
Curlex blankets typically last 90–120 days, long enough for vegetation to establish. Degradation rates vary based on site moisture, temperature, and exposure.
Can Curlex be used in waterways?
Yes, Curlex excels in low-flow channels, roadside ditches, and swales. Its ability to resist shear stress makes it a smart option for erosion-prone areas near water.