Hands down, the best way to protect young trees is with tree tubes (also called tree protectors). They not only ensure your seedlings get past the vulnerable seedling and sapling stages, it also enhances growth rates. Deer seem to key in on tender seedlings and saplings as both a food source and a target to rub their antlers on. Tubes protect the young trees from both, as well as from rodents that might chew on the bases potentially girdling and killing them. Meanwhile, tubes enhance growth by acting like a tiny greenhouse, increasing photosynthetic and transpiration rates. They also trap and direct precious moisture to the root system.
Tree tubes are efficiently designed to protect young trees. Rather than wood, we use a schedule 40 PVC pipe/stake that can be reused. They come pre-threaded with zip ties so once you plant your tree you drive your stake, slide the tube over and cinch it tight. The upper part of the tube is vented to allow circulation and prevent the interior from becoming too hot. The bottom is not vented so you can still spray competing vegetation with herbicide if need be without damaging your young tree.
Tree tubes have been around a while, and they used to be not as necessary before deer populations skyrocketed. Now days if you don’t tube (or at least cage) your trees, don’t expect them to make it more than a year or two. Tree tubes definitely add to the overall cost, but it’s a small price to pay knowing that using them will provide a mature tree in the near future instead of having to replant.