I'm curious to know if anybody ended up trying coffee foliar spray (or any liquid caffeine such as tea) and if so what were the results?
Plants make caffeine as a natural insecticide and it seems that it is also deadly for slugs and snails at 1-2%, which is about the amount in coffee. However, it may also be bad for many plants as caffeine seems to be allelopathic and may cause leaf burn? Caffeine also can be anti fungal and antibacterial, I wonder if that would be bad for soils or good bacteria?
In general, if I could get a good-bacterial foliar spray that I could trust, I would use that. I'm not sure if that would help my situation.
I have a big snail and slug problem. Older plants get along okay, but for herbs and baby plants, I'm searching for a solution that doesn't require transplanting. I would like to plant in place in the garden, but those babies are no match for the army of slugs! Manual stomping has been insufficient.
Caffeine also is harmful to ducks, but I have no data on how much it would take to harm ducks. I would like to have ducks in the future, but I am usually travelling for about three months each year, which makes animal systems hard for me at this time. Hopefully it would wash off long before duck time.
If caffeine foliar spray is useful, leftovers from the day's brew could be sprayed occasionally on the babies.
So: anybody tried it?