Burlap is a coarse, woven fabric recognized for its rustic texture and wide application in packaging, crafting, and horticulture. The answer is generally yes, as raw, untreated burlap is entirely biodegradable and can safely return to the environment. This characteristic makes it a popular choice for gardeners, who use it for root ball wraps and erosion control, as its natural composition allows it to integrate into the soil without leaving behind synthetic waste.
The Core Material: Why Burlap Decomposes
The decomposition of burlap is directly tied to its source material, which is most often the natural fiber jute, harvested from the stalk of the Corchorus plant. Like all plant matter, the structure of the jute fiber is largely composed of two primary organic polymers: cellulose (58% to 63%) and lignin (12% to 15%), classifying it as a lignocellulosic material.
These complex carbohydrates are the food source for a diverse community of microorganisms found in soil and compost environments. Fungi and bacteria secrete specific enzymes, such as cellulase, that hydrolyze the long cellulose chains into simpler sugars, which is the mechanism by which the material breaks down. Lignin provides the fiber with rigidity and resistance, making it more challenging for microbes to process, so it decomposes at a slower rate than the cellulose.
The action of these decomposers facilitates the recycling of carbon and nutrients back into the ecosystem. Specialized white-rot fungi are particularly effective at breaking down the recalcitrant lignin polymer.
Decomposition Timeline and Environmental Conditions
The speed at which a piece of burlap degrades is highly variable and depends entirely on the conditions of its environment. Under optimal circumstances, such as being shredded and fully incorporated into a hot, active compost pile, burlap can begin to disintegrate noticeably within a few weeks to a few months. When buried directly in garden soil, the process slows, typically taking anywhere from three months to two years to fully break down.
Moisture content is the single largest accelerator, as it is required for microbial life to thrive and transport the necessary digestive enzymes. A consistently damp environment provides the ideal habitat for the fungi and bacteria responsible for breakdown. Burlap left exposed to dry air or cold temperatures will remain structurally intact for significantly longer periods, potentially over a year.
Temperature also plays a significant part, with warmer conditions speeding up the metabolic rates of soil microorganisms. Decomposition rates increase noticeably during warm summer months compared to the cooler, less active periods of winter. Furthermore, the presence of nitrogen in the environment acts as a fertilizer for the microbes, accelerating their ability to break down the carbon-rich cellulose.
The grade or thickness of the woven material is an additional consideration that influences the timeline. Heavy-duty burlap contains a higher density of fibers, presenting a larger mass for decomposers to process. Thinner, looser weaves will naturally break down faster than tightly woven, heavy material used for applications like tree moving.
Identifying and Avoiding Non-Compostable Burlap
While raw jute burlap is fully compostable, consumers must be cautious, as not all products labeled as “burlap” share this property. The most common impediment to decomposition is the inclusion of synthetic fibers, particularly polypropylene, which is a petroleum-based plastic. This plastic is often woven into the jute to increase tensile strength or reduce manufacturing costs, but it will persist indefinitely in the environment.
Chemical treatments are another factor that can severely impede or halt the natural decomposition process. Burlap used in commercial or industrial settings may be treated with petroleum-based rot-proofing agents or various flame-retardant chemicals. These substances are specifically designed to resist microbial action and prevent decay, rendering the material unsuitable for composting or direct soil incorporation.
Identifying true natural burlap requires close inspection, starting with the product labeling, which should specify 100% jute. If the origin is unknown, a simple burn test can distinguish the fibers. Pure jute yields the following results:
- It will ignite easily.
- It will smell like burnt paper or wood.
- It will crumble into fine, soft ash.
Conversely, synthetic blends will often melt, drip, produce black smoke, and leave behind a hard, plastic residue.