Vinegar and Plants

Most recent answer: 10/22/2007

Q:
I want to do a project about plants and vinegar. What kind of plant would you seggest to use? I want to soak the plant in the vinegar with out any soil and record how long it would take to die in different brands of vinegar -fay
- fay (age 12)
sarasota school of arts and science, sarasota,fl usa
A:

I don’t know enough botany to know what plants would live long enough in vinegar to make this experiment doable. But I do want to suggest that you might want to think of another experiment. After all, once you’re going to the trouble of doing an experiment, why not pick one that you’re interested in, either because the results have some practical value or because they help you understand the world better? Is there really something about brands of vinegar killing plants that especially interests you?

It’s hard to figure this out via slow Web responses, but perhaps you know some scientist you could talk with who could help you figure out an experiment that would really get somewhere.

Mike W.

Vinegar consists of acetic acid and water. Most brands have similar concentrations of acetic acid. The differentiation often comes from flavorings or other impurities, which will probably have a tiny effect on your results. I’ll bet there’s more variation in the initial hardiness of plant specimens you may find than variation due to the different vinegars.

You can get higher concentrations of acetic acid than vinegar. "Glacial" acetic acid is sold in photography supply stores -- it is highly concentrated. People use it to mix "stop bath" for developing black and white film and prints, because soaking in vinegar a print or film after it’s been dipped in developer solution will make the developing process stop. You don’t want to develop too long because then all your prints will come out black (or your negatives will be black, making white prints). Stop bath is made by diluting the concentrated acetic acid in water. But beware! Highly concentrated acetic acid can burn your skin, and irritate your eyes and lungs. Please do not go near it without adult supervision. It’ll probably kill your plants very quickly. I’m not sure what you’d learn from that, though.

Some plants may survive in dilute vinegar! I’m not a botanist either, so I don’t know which ones, if any, but aquatic plants which can thrive without soil would be a start. Finding which plants survive in vinegar may be more interesting than finding out which brands of vinegar kill plants the quickest.

Tom

(published on 10/22/2007)