Do tomato plants like caffeine? Why?

A lot of sites says fertilizing your tomatoes with coffee grounds helps growth. So I was wondering if it was the caffeine that was responsible for this or at least how it helped. I looked it up and got no answers for what i was looking for to the fact that tomatoes like caffeine and why.

By looking it up, I know acidity and nitrogen have to do something to do with the reason that coffee grounds help tomatoes grow. But why does CAFFEINE? Having nitrogen provides leafy growth and tomatoes like soil which has a pH of 5-7 but how doe CAFFEINE contribute to this?

Please help and quick i need this info for my science fair which is in like 2 days!

Welcome, Penny Lu!
I don't know about the caffeine...but do tomatoes like acidic soils? Coffee grounds would be quite acidic, I would think.
Good luck with the science fair!

I had read that your initial coffee has a lot of the acids in it. The grounds don't have much acid left. I've put them around my tomatoes, and never noticed much difference. Yes, good luck with your science fair project. We did those a very long time ago!

I'm with you Karen. The coffee grounds add organic material to the soil which help it to retain moisture and nutrients, but don't have much in the way of nutrients that plants can use.

Caffeine is a stimulant for humans and other animals including insects, but not for plants. It might be toxic to insects in the soil, though, which might help the plant a little bit.

I'd recommend you do a science fair project next year where you add coffee grounds to one tomato plant in a pot, and no coffee grounds to another. Water and fertilize the same for both and see if there's any difference after about a month. (obviously too late for this year)

How about a third plant with decaf?

Caffeine is an organic pesticide, plants produce it as a defense mechanism against herbivorous insects. It's possible it might provide some level of protection for the tomatoes against insects, although I would think the effect, if any, would be small.

KentPfeiffer said:Caffeine is an organic pesticide, plants produce it as a defense mechanism against herbivorous insects. It's possible it might provide some level of protection for the tomatoes against insects, although I would think the effect, if any, would be small.

Wow, Kent! That is super cool to know!