For two days, the homeowner of 307 Flanders Rd. in Woodbury let ashes cool in a container before dumping them into the compost pile, Woodbury Fire Chief Janet Morgan said.
The wind conditions were just right and a brush fire started, she said.
"That's why we keep reminding people to add water and stir the ashes up and then add water again and stir it up again," said Morgan.
Ashes can stay hot enough to ignite for four to five days after burning, according to Morgan. Earlier this year, she gave tips on how to properly dispose of ashes.
"Thank goodness we got there when we did," said Morgan. "There was a shed right there."
She and other firefighters went to the scene after receiving a call from Woodbury First Selectman Gerald Stomski, who was driving in the area and noticed black smoke.
Fortunately, the fire didn't spread to the shed and no one was injured, she said, adding that two kayaks melted from the blaze.