Is the smell given off by a mint plant’s leaves a genetic coincidence (or artificially selected for by man) or does it, for instance, help to repel insects that may wish to feed on the plant?
The latter. Most aromatic compounds found in the vegetative parts of plants or in their seeds, including many compounds we use as spices, are actually repellants for insects or other herbivores.
Farmers plant it in peat low lands. They grew it in a number of places around Portage and it’s a lot more pungent than people realize. It can irritate the skin and acres of the stuff can take your breath away when damaged. We could smell the farm about 5 miles away after a strong storm. You can smell it from much farther away when it’s cut. The smell from the bruised leaves would discourage me from walking in it. I don’t remember them having deer damage either, when they’ll eat every thing else farmers planted. They reduce the plants down to a concentrate and ship it to market. You don’t want to have a spill of that stuff. I think a 55 gallon drum of it sold for about $4,000 twenty years ago.