Sungrower Black and White Grow Bags are black on the inside and white on the outside to create a light-proof barrier against algae growth while providing 92% reflectivity to ensure a cooler root zone. The bags are UV stabilized and constructed with holes to prevent pockets of excessive moisture throughout the grow bag. Sungrower Black and White Grow Bags are great even in hot environments because they can regulate temperature as excess heat is able to escape from all sides of the grow bag, keeping the roots cool and your plants happy!