Okay this might be a dumb question or not but I have never owned pets so I have to ask

Hi, yeah. You can do strong Velcro on the bottom of the plant and on the shelf. Other options are double sided adhesive if you don’t want the plants moved for watering etc, or strong magnets- but you might find that your cat will chew or destroy the plant. I know my sister can’t have some indoor plants because they’re dangerous for her cats who will chew on them.
So that might be something to research

I could set up a locking mechanism for under the plants. It would be really easy.

If the earth was flat cats would have pushed everything off the edge by now.

Those plants would be a nice challenge for a cat.

You need to secure them.

Older grumpy cat from the shelter maybe not a problem. Spicy kitten... not a chance! Kiss em goodbye.

Cats will for sure get them - may7be not right away, but it will happen. I tried tried several ideas to anchor them down, but it makes it a pain to take them down and water. What I finally ended up doing is getting a roll of Cat Scat Mat with Spikes, cut to size to the shelf and cut a hole the same diameter as the pot.

It works great and I've not had a problem since.

It really depends on the cat, but I can see a cat wanting to take over those shelves. A little raised edge around the perimeter could be enough to keep the plants in place... depending on the cat.

You never know about cats. The last house cat I had was very careful and respectful about everything in my apartment. I don’t ever remember her breaking anything

Sooo... They have Pet Safe stuff at Pet Stores (You can probably even order online now) That you spray on your stuff to deter them from messing with it... HOWEVER... When me and My sister where teenagers my Sister had a cat and my Mom bought some of that stuff cause my sisters cat kept Climbing up in our Christmas Tree that year... The guy at the pet store "Oh Yeah this is really good stuff... Cat won't be Nowhere near the tree" YEAH LOL My Mom Sprayed the Christmas Tree and we leave and come back and our Demon Cat Was right back up in the tree when we got back LOL He DID NOT CARE one Bit 🤣🤣🤣🤣🐱🐱🐱

Cats are like people.... Some have amazing ability to climb and not knock things over... Then there's the clutzes of the cat world 😛

Just make it so they can’t get up onto them.