2 inch Corrugated Plastic tree protector, 2 feet tall. These products are exactly what we use to protect our young trees throughout the fall/winter/spring from rodents and Sun Scald.
Recommended, 1 per tree, or 2 per tree if snow is higher than 2 feet.
***Black plastic pipe is not recommended as it warms up in the sun and also contributes to Sun Scald during winter months.
***Drain tile is not recommended as it is usually too big for young trees and creates a haven for rodents between the plastic and the tree.