A large pile of mulch at the Living Earth landscaping facility off Crawford Road caught fire early Monday morning, fire officials said.
Houston firefighters responded to the facility around 3:30 a.m.
As of 11 a.m., the fire was still burning. Fire officials said they expected to be at the site for most of the day.
The exact cause of the fire is unknown, but mulch material is known to spontaneously combust, especially in warm weather.