If your idea of a holiday evening with friends or family includes sitting around a crackling fire, here’s some advice on the wood to burn, from ISU extension forestry specialist Paul Wray. He says red oak produces good heat and nice coals, and leaves little waste, though elm, ash and hickory are also good for fireplaces. By the same token, the wood expert can recommend some kinds of wood to pass up for fire-building material, especially if your fireplace or woodstove doesn’t have a screen or doors. Conifers, or fir trees, put out a lot of sparks and don’t burn as well as hardwood, and others like cottonwood also don’t burn as hot because the wood’s less dense. And Wray wouldn’t put the holiday tree in with the firewood when you’ve taken down the decorations. He says you could cut it down to a piece of firewood, but putting in branches, needles and all, will add fuel that’s almost explosive when it burns. In past years homeowners often paid a price in lost heat from the luxury of having a fireplace, but Wray says they’re better-designed these days. Wray says an annual check is a good idea for the fireplace, which includes an external air supply, the chimney, and a system that can leak heat if there are cracks in it.