Q: The person I work next to has a desk loaded with plants. She is frequently away and because I'm the person who sits nearest them, I'm always tasked with watering them in her absence. I didn't mind at first, but it's getting really annoying. I've told her I don't want to do it but she says that because I'm the only one in the office every day there's no-one else who can. I've already tried sabotage but the plants seem to be fairly hardy.
A: I bet you're not really fed up with having to water those plants. Few plants need watering every single day (what happens at weekends, for example?), and I can't believe it takes you more than 10 minutes, anyway. I bet you're fed up with the plants' rightful owner and the fact that she so airily takes you for granted.
In truth, you've never really got along; and now you've allowed the great Plant Watering Problem to become the focus and justification for this uneasy relationship. Before very long - if it hasn't happened already - you'll become so obsessed with this trivial business that it will start to affect your work and other relationships. (If you seriously tried to sabotage those innocent plants, it suggests that it has all got a bit out of proportion already.)
Office life can get a bit claustrophobic at times. Petty irritations take on an absurd significance. Internal grievances feed on themselves. Just about the only way to break such a pattern is to do something consciously disruptive and unexpected. In your case, you need to do something that tests your relationship.
So when the plant-owner returns from her next trip away, why not have a note waiting for her? 'Dear Rhoda, your bloody plants are getting me down. I know it's ridiculous but they're really getting to me. Can we have a drink in the pub tonight and sort it out, please?' (You can certainly improve on that; you know her better than I do. But you get the idea.)
She'd have to be a very cool cookie indeed not to respond to such an open approach. And with any luck, as you get to know each other a bit better, those bloody plants will stop being such an emblematic issue between you. You might even grow fond of them.