For up to 1.5" caliper trees - Uses 99% LESS WATER than traditional tree bag over the course of 1 season! Leave out year-round - even in frozen climates! Cover with mulch to help keep soil moisture levels at optimum levels, while reducing evaporation, providing insulation to the root system and keeping the SteadySpring by TreeDiaper from getting stolen! Soak first for a couple hours. SteadySpring will function for 30 days without refilling and maintain effectiveness for years with as little as 1 inch of rainwater per month. You could go months or years without refilling! SteadySpring uses osmosis and gravity to slowly leach water into the soil 12-14 in deep