The needle foil is a black protection foil, which is permeable to water by its perforation. It protects against uncontrolled growth of algae and reduces the evaporation. The foil should be used with garden fleece. Garden fleece serves as a good substitute for perlite. It absorbs the water and gives it away with all nutrients to the plants. The needle foil protects the garden fleece against soiling - together they are a dream team! It protects the roots against drying up, because there will be no flooding. The roots remain white and healthy.