Small diameter plastic mesh seedling protectors will protect most conifer seedlings. Most are effective until the seedlings grow taller than the tube height. The relatively small (1- to 3-inch [2.5- to 7.6-cm]) diameter tubes do not protect much competing vegetation and also allow lateral branches to grow through the mesh. The advantage of plastic mesh protectors over some other control methods is that they provide protection from a variety of animals including deer (Odocoileus spp.), hares (Lepus spp.), elk (Cervus spp.), and voles (Microtus spp.). The cost of installation can be high but can be reduced if done at the time of planting. Tree seedlings that become established and reach 30 inches (76 cm) or more in height are less susceptible to damage.
Plastic mesh seedling protectors photodegrade (i.e., sunlight will break down the plastic) and deteriorate after several years. Although they expand with stem growth, they probably provide little protection from girdling of large diameter stems by mountain beavers.
Wire mesh cages 1 to 3 feet (0.3 to 1 m) in diameter will protect individual trees but are expensive and may be climbed over and burrowed under. These cages also allow competing vegetation to be protected and often cause poor tree growth. The wire used in these cages may injure tree growth if cages are tipped or come into contact with the tree stem.
Resources: (online)
Mountain Beavers
