How does caffeine affect plant growth?

Caffeine

Minerals like potassium are often found alongside caffeine when it occurs in plant sources like coffee beans, and that could help the plant grow faster. But the caffeine itself would be unlikely to have any affect on the plant's rate of growth.

I tested it and the plant grew at normal rate but the leaves were more wrinkly and browner

Answer 2:

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.

Although you can use either a thin or thick layer of coffee grounds, make certain you do not cover the grass to the point that water is repelled. Watch out for gophers that might be attracted to your coffee grounds fertilizer. On the plus side, earthworms will also be drawn to your unique fertilizer.Since earthworms have the ability to eat enough in a 24-hour period to equal their body weight, your lawn will benefit.