The Crepe Myrtle (Lagerstroemia indica) is a popular ornamental plant in the southern United States, known for its vibrant flowers and smooth bark. Since this common landscaping tree requires regular pruning, many homeowners wonder if the discarded wood can be used as a fuel source. Evaluating its worth requires examining its physical properties, density, and combustion characteristics.
Assessing Crepe Myrtle’s Wood Density
The heat output of firewood is directly related to its density, measured by British Thermal Unit (BTU) content per cord. Crepe Myrtle is a medium-density hardwood, producing approximately 23.8 million BTUs per cord when seasoned. This favorably positions it, nearly matching high-quality firewoods like Red Oak and White Ash (around 24.5 million BTUs per cord).
However, Crepe Myrtle has a major limitation in the volume of usable timber it provides. Since most are grown as multi-trunk shrubs, the wood harvested is primarily smaller-diameter limbs and trunks. Although the wood fiber is dense, the total burnable material gathered from a typical ornamental tree is low compared to large timber species. The wood burns hot but fast, and its poor coaling properties mean it does not sustain a fire for long periods.
Handling and Preparation Challenges
Preparing Crepe Myrtle for firewood presents practical difficulties rooted in its natural growth habit. The typical ornamental form has multiple twisted, small-diameter trunks and branches. This scraggly structure results in wood with an irregular, knotty, and non-linear grain pattern, making splitting larger pieces challenging and inefficient.
The small size of the limbs allows the wood to season more quickly than large logs. However, the wood is highly prone to cracking and checking as it dries if left unprocessed for long periods. For the average homeowner, the time investment required to process small, irregular pieces often outweighs the benefit of its moderate heat output. The wood is generally easier to chop into smaller chunks for kindling rather than splitting into traditional logs.
Smoke Characteristics and Safety Profile
Once properly prepared and fully seasoned, Crepe Myrtle is safe to burn and does not release harmful or toxic fumes. The wood is not resinous, which contributes to a low sparking tendency, producing minimal popping or spitting embers as it burns.
Crepe Myrtle tends to produce a moderate amount of smoke, especially if it is not completely dry. Some users report this smoke can be irritating. This heavy smoke production makes the wood better suited for outdoor fire pits or a well-drafted wood stove rather than an open indoor fireplace. It is not known for causing excessive creosote buildup in flues and chimneys.