Garden Variety: Burn local firewood before spring

Fall’s cooler weather means area residents are picking up bundles of firewood for their stoves, indoor and outdoor fireplaces, fire pits, chimineas and even a little late season camping.

If the wood is locally harvested and burned before spring, it poses little risk to the environment. Firewood that is shipped in from other states and held over until the spring, however, has potential for introducing insects and diseases that are problems in other parts of the country to Kansas forests.

There are a couple of things to look for to ensure that the firewood you are purchasing is pest-free.

First, look for the county of origin which should be on the label and may differ from the location of the producer. If the wood originated in your home county, it is probably safe. If the wood is unlabeled, ask the retailer about the source.

Second, if the wood is from another state or region, look for a USDA Certification Shield. USDA has agreements with some large firewood producers who heat-treat wood in order to legally move it from pest-infested areas.

Burning firewood in the season that it is purchased will also significantly reduce the risks of introducing or spreading exotic pests in the area. Spring and summer are more favorable times for insects to emerge and disease-causing fungi and bacteria to become active. If you end up with leftover firewood when spring arrives, have another bonfire rather than holding the wood through the summer.

The pests that USDA and tree lovers in Kansas are most concerned about are emerald ash borer, thousand cankers disease of walnut, gypsy moth, Asian long-horned beetle and pine wilt.

Emerald ash borer has wiped out millions of ash trees in the Midwest since its arrival in the United States in 2002. USDA considers it to be the most destructive insect pest on record in North America. Johnson, Leavenworth and Wyandotte counties in Kansas are known to be infested with emerald ash borer and are under a federal quarantine restricting the movement of ANY hardwood firewood from those counties.

Missouri and Iowa are also infested and under federal emerald ash borer quarantine, along with nearly all of the states east of them.

Thousand cankers disease is a fungal disease specific to walnut that is mostly a problem in western states. Kansas is currently revising the quarantine on movement of walnut wood into the state.

Gypsy moth is a problem in the eastern part of the U.S. You may see firewood with a USDA Certification Shield noting that the wood has been heat-treated for gypsy moth.

Asian long-horned beetles have been found in the far northeast and are also extremely destructive.

Pine wilt is a local problem affecting pines in the eastern half of Kansas, in Nebraska, Missouri and possibly other states in the Midwest. Avoid taking wood from dead pine trees out of the area to minimize the risk of spreading the disease further throughout the United States.

— Jennifer Smith is a former horticulture extension agent for K-State Research and Extension and horticulturist for Lawrence Parks and Recreation. She is the host of “The Garden Show” and has been a gardener since childhood. Send your gardening questions and feedback to Lawrence Living@ljworld.com.