What is it in aspirin that makes flowers perk up?

Answer 1

I think that's just an old wife's tale. I never saw it to work.

Answer 2

" Aspirin is an activator of 'systemic acquired Resistance' (SAR). And that plants, when under stress, naturally produce salicylic acid, but not fast enough and in sufficient quantities to really help them out in time. So the bugs get them, and diseases get them, and they show even more stress.

"But if you give them aspirin, it helps boost their immune system, kind of like feeding people echinacea so they don't get a cold. "
I hope this answers your question.