About 5,000 wreaths are donated by the Worcester Wreath Company of Harrington, Maine. The owner, Merril Worcester, also pays for the trucking expense. He's done this since 1992. Groups of Maine school children visit this event to help out, along with their regular school trip to DC. Harrington, by the way, is one of the poorest parts of the state.
Rest easy, sleep well my brothers and sisters.
(hat tip to Auntie A and Marshall)