The <a href="https://greenhousecover.com/product/over-winter-plastic/" target="_blank" title="">best greenhouse plastic for winter</a> winter is typically a UV-resistant 6-mil polyethylene film designed for cold climates. This material offers excellent insulation reducing heat loss and protecting plants from frost. Look for options with anti drip features to prevent condensation from harming crops and a high light transmission rate to maximize sunlight during shorter winter days. Double layer polyethylene with an air gap can further enhance insulation. Durability is also key choose plastic that can withstand snow load and strong winds. Investing in quality greenhouse plastic ensures a stable warm environment helping plants thrive even in harsh winter conditions.