GroXcess Black & White Grow Bags,1 gal, 100 PackIn Store Location: @J10 GroXcess Black & White Grow Bags, gal, 100 Pack GroXcess Grow Bags are black on the inside and white on the outside to reflect light back to the plants while maintaining healthy root temperatures. These UV stabilized polyethylene bags are fluted, stand upright when filled with growing medium and have prepunched bottom holes for thorough drainage. One gallon bags measure 5. 4 inches by 4. 9 inches by 12. 8 inches. Pack of 100.