My cat keeps destroying my flower spikes--help!

[Daenerys]

I live in a small apartment that I share with my cat. The orchids grow on shelves under lights in the bedroom, and for the most part, the cat ignores them. I keep the bedroom door closed when I am not in that room, so he's rarely in there alone.

My cat goes after the flower spikes, and bites off the tips. He'll ignore the plants until the spikes are just about to flower, and then destroy them. I try to be vigilant, but it takes months for a spike to mature, and he needs to only swipe at it once to destroy it. He's destroyed 4 spikes this way already over the past few months.

I don't have room to move orchids to a place where he has no access to them, and I don't know how to train him to avoid them, when 90% of the time he doesn't go near them. And when he does get to a spike, it takes him so little time to destroy it, that by the time I get to him with a spray bottle, he's already run off to hide in a kitchen corner. I can be 99% vigilant, but the one time I get lax is enough to lose the flowers.

Please help. I lost a tolumnia spike today, while I had my back turned to him for less than a minute, and I'm at a loss as to what to do.