5 easy ways to cat-proof your Christmas tree Consider the size of the tree. A smaller tree will be better for cats if they do indeed end up climbing the tree. To prevent smaller kittens from climbing the trunk, wrap tinfoil around it. Choose a strong base. A strong base is especially important not only if you have kittens, but also for small children and babies. Don't place the tree anywhere near climbing items. This will deter cats from jumping onto the tree. Consider not decorating the tree right away. Decorate it as close to the holiday as possible, or if you need to, try spraying the tree with a product bitter apple, or use citrus. Cats are repelled by these odors. Choose ornaments that are less likely to attract your cat's attention (no glitter, glow) and place them in the top two-thirds of the tree.