Do not remove the ashes—or close the damper—until at least 12 hours after a fire has burned out. Then skip the ash dump that may be built into the fireplace, which only postpones the cleanup and can potentially leak fumes into the house if the chimney is old. Instead, use a hearth shovel to transfer the ashes into a metal container with a cover. "Move that outside and away from the house and let it sit for a couple of weeks, because coals can smolder for a long time," says Judy Comoletti, of the National Fire Protection Association. Then douse the ashes with water and sprinkle them over your lawn and non-acid-loving garden plants to add nutrients and raise pH levels. You can even mix the ash into your compost pile to help maintain a neutral pH and encourage the breakdown of organic materials.