The Waterboxx® and Growboxx® plant cocoon can refill themselves. However, you need to fill the planting hole one day before planting with water. 5 Gallons if the soil is clay, 10 gallons if the soil is sandy. The day after you plant, if you still expect rain, we advise you to add the prescribed 1 gallon in the middle to establish the tree and 1 gallon in the box. If it rains, 4 inches is enough to fill the box completely.