Especially if they can be decorated with small baubles of catnip.

I solved the problem a couple of years ago. I haven't bothered to put up a tree since my wife died. With only me in the house, why bother?

Fat overfed underexercised cats if they can't jump that high.

Cat proof? Are you new to cats? lol They find a way into EVERYTHING! I had one once type a message on FB to a friend. It was something along the lines of "aioshdgfuWUIO[UAGVUORG". He thought I was arguing with him. He replied. More words of wisdom from my end "asfohbaoebhoaenb" or whatever. I got another reply. When I woke up I was like WTF, then laughed my hull off! Too bad they couldn't break something I don't care about. Like the vault at the bank. lol They could do it if they wanted!

Cats are amazing creatures! I've said this before, but I like ANY cat more than most humans. Even the one that had a bad mental condition and would attack anything (including itself) violently from time to time. No joke. I warned the vet. He didn't believe me. But the guardian was going to uthanize her, and I told myself I would give her a good home. She had one until the day she died. She got outside and was probably attacked by a badger.

So far I've been so lucky when Kimbo eyed the tree I told him no very firmly and he just walked away. I do not intend to ever let him in the living room unsupervised until the tree is down.

My tree is on a table but the tables right next to the sofa so it would be no problem for him to take a leap and get to it.

Or when the kitties are the tree....

Yeah, that first tree ain't cat proof, at least not for my idiots. That is a tiny hop, and they would try it as long as it takes to knock it down.