The Palo Verde tree is a common sight across the Southwestern United States deserts, often leaving property owners with fallen branches. This species, whose name is Spanish for “green stick,” can be burned, but it comes with significant limitations that make it a poor substitute for traditional firewood. While the wood is combustible, its characteristics mean it is often best suited for specific outdoor uses rather than for heating a home.
Safety and Suitability for Burning
The wood is generally considered non-toxic, meaning no poison is released into the air during combustion. However, burning it indoors is discouraged due to safety and air quality concerns. One primary issue is the high tendency of the wood to “pop” and throw sparks and embers as it burns, which presents a fire hazard in an enclosed fireplace or wood stove. This behavior is caused by the wood’s fragile, porous structure as it heats up.
If the wood is not fully seasoned, it can produce excessive, pungent smoke. This smoky output increases the risk of creosote buildup inside chimneys and flues, a highly flammable residue that can lead to chimney fires. For these reasons, Palo Verde wood is safer and more suitable for outdoor use in open fire pits or campfires, where ventilation is not an issue.
Performance Characteristics as Firewood
Palo Verde is a light, low-density wood, which determines its performance as a fuel source. This low density means it contains less mass per volume compared to traditional hardwoods like oak or mesquite, resulting in a low British Thermal Unit (BTU) output. A typical cord may yield an estimated 12 to 15 million BTUs, notably lower than dense hardwoods which often yield over 25 million BTUs per cord.
The light structure causes the wood to burn quickly, limiting the duration of the heat it provides. This fast burn rate requires frequent replenishing to maintain a consistent heat source. Furthermore, Palo Verde wood generally does not produce long-lasting, glowing coals, instead breaking down rapidly into a quick, white ash. The inability to form a substantial coal bed means the fire will not retain heat effectively, making it inefficient for long burns or overnight heating.
The wood’s scent when burned can be unfavorable, with the subtle fruity scent of fresh wood turning sour and unpleasant when lit. Palo Verde is not typically chosen for smoking due to this odor. Its rapid ignition, however, makes it useful as lightweight kindling to start fires quickly before introducing denser woods.
Essential Preparation and Seasoning
Like all firewood, Palo Verde requires proper seasoning to reduce its high moisture content and ensure a clean, efficient burn. Freshly cut, or “green,” wood can contain up to 50% water by weight, and burning wood with a moisture content above 20% is inefficient and produces excessive smoke and creosote. The wood must be split into usable sizes immediately after cutting, as splitting increases the surface area exposed to air, accelerating the drying process.
The recommended seasoning time for Palo Verde is typically six to twelve months, though this depends heavily on local climate conditions. To promote drying, the split wood must be stacked off the ground to prevent moisture absorption and covered only on top to shield it from rain. Crucially, the sides of the stack should remain open, allowing wind and air to circulate freely through the pile. Properly seasoned Palo Verde will be lighter and will produce less smoke and fewer embers, improving its performance and safety profile.