Those cages would be made of 1/4 inch mesh hardware cloth, a welded wire product. For trees you would need a to make a very large cage, and it would need both a top and bottom to prevent invasion from above and below.

check out the link.. scale it up for whatever plant you need to protect

ken

Here is a link that might be useful: link

Unless you make EXTREMELY large cages, you'll need to treat your trees and shrubs like container plants as their root systems become severely restricted.

Some things to consider will be a limited ability to access water and nutrients, wind throw, and the strangulation of roots as they become large.

Please know that moles don't feed on plants...not their roots nor any other part. :-)