Hmm, that's a tough one! Cats love to explore and climb, so it can be hard to keep them away from the tree. One solution is to use a spray bottle filled with water, and every time your cat approaches the tree, gently spritz them with water. This will teach them that the tree is off-limits. You can also try placing some tinfoil or double-sided tape on the branches, which will make it less appealing for your cat to climb. Lastly, you could try distracting your cat with a new toy or activity that will keep them occupied elsewhere. Good luck!