I have a rosemary plant and I gave it beer instead of water and my plant got sick and turned brown. I have another plant which I watered with water and it grew perfectly fine. I want to know how exactly the beer affected the plant since I can’t seem to find the answer and I've been researching for quite a while but I can’t figure it out.
Beer and Rosemary Plants
Certified GKH Gardening Expert
While there has not been too much hard study done on this, what little research there is suspects that the high sugar content in beer helps to accelerate the naturally occurring bacteria, fungus and microbes in the soil, which attack the plant.
Also, the alcohol may cause the roots to take in less water, which stresses the plants (and makes them even more susceptible to the previously mentioned attackers.)