Potting Soil Quantity For Containers For Pots 6” 4 qt. bag 8” 4 qt. bag 10” 8 qt. bag with some leftover 12” 8 qt. bag 14” 16 qt. bag 16” 16 qt. bag with some leftover 18” 32 qt. bag Larger sizes—please ask for greenhouse assistance  For Window Boxes 24” 16 qt. bag 30” 16 qt. bag 36” 32 qt. bag with some leftover 40” 32 qt. bag 42” 1 cu. Ft. bag 44” 2 cu. Ft. bag with some leftover 48” 2 cu. Ft. back