With the onset of winter, county agricultural officials are reminding residents to buy only locally produced firewood.
Buying local reduces the chance of bringing harmful insects and plant diseases into the county, said Martin Settevendemie, county agricultural commissioner.
For example, an insect likely imported from Arizona on firewood has killed more than 80,000 oak trees in San Diego County during the last decade.
The best safeguard against unwanted pests and plant diseases associated with firewood is to buy your firewood from a source close to where you intend to burn it, Settevendemie said.
He also urged consumers to make sure they are getting the amount of wood they paid for. Firewood must be sold by cord, defined as 128 cubic feet of neatly stowed and stacked wood.