How does caffeine affect plant growth?
Caffeine does not do anything to a plant directly. But caffeine is used by many plants as an natural insecticide which paralyzes any poor insect unlucky enough to start eating the plant. Larger mammals and primates like humans find it has a minor stimulant effect but in higher doses it acts like the intended insecticide effect, causing tremors, extreme anxiety, muscle problems, tachycardia, and sometimes death. Yup, caffeine is just a insecticide that is mildly stimulating. Kind of how they used to use strychnine as a stimulant.
