Officials say the fire, which burned for two days, was under control on Tuesday, although the Wilmington Fire Department will stay at the scene for 24 hours or longer.
Traffic on Christiana Avenue is still limited.
The mulch fire began Sunday at a recycling facility. High winds blew the fire from one mulch pile to another.
One firefighter was reported hurt combating the blaze. The injuries weren't considered life-threatening.
Information from: WDEL-AM