Your locally grown Christmas trees, wreaths, and boughs will stay fresher longer and smell amazing. A list of markets where you can stock up on holiday greens follows:

Durr Wholesale: Wreaths (Union Square Greenmarket Saturday) 
Big Yellow Sun Farm: Wreaths (Union Square Greenmarket Saturday)
Lebak Farms: Wreaths and boughs (Grand Army Plaza Greenmarket Saturday)
Luna Family Farm: Wreaths and bouquets (Stuyvesant Town Greenmarket Sunday; Union Square Greenmarket Wednesday & Saturday)
Mountain Sweet Berry Farm: Wreaths, garland, and princess pines (Union Square Wednesday, Friday, and Saturday)
Rexcroft Farm: Wreaths (Fort Greene Greenmarket Saturday) 
River Garden: Dried flower wreaths (Union Square Greenmarket Monday, Wednesday, Friday, and Saturday)
Stokes Farm: Herb wreaths (Tucker Square Greenmarket Thursday and Saturday; Union Square Greenmarket Saturday)
Van Houten Farms: Trees and wreaths (Union Square Greenmarket Wednesday, Friday, and Saturday)