Proving that the world never stops being weird, scientists found an unexpected property in two common household herbs. For some reason, they contain a chemical that stops another plant from sprouting.
Some of you might enjoy a soothing mint tea in the evenings. If you do, you're sipping up a brew of chemicals. The most prominent of these is menthol, but it's backed up with a fresh-tasting chemical called carvone. Carvone is roughly hexagonal, sprouting a couple of branches which end in various carbon and hydrogen combinations. One form of carvone, s-carvone, is present in spearmint. Another kind of carvone, a mirror image known as r-carvone, dominates in caraway seeds, which have a licorice-like taste to them.
Both of these chemicals are of use to the plants that possess them. They are antimicrobial agents that kill off both bacteria and fungus. It's easy to see why the herbs would have them. Less easy to see is why they seem to have a major effect on an unrelated plant. Both forms of carvone have been shown to stop potato tubers from sprouting. The caraway seed carvone did a better and more immediate job than the mint carvone, but both shut down the potato's ability to sprout. Why? Is carvone an inhibitor of other plants, plants that compete with the herbs for space or sun? Or is it just one of those coincidences, in which two species are inherently chemically incompatible.
Either way it might work out for us. Companies have been working on solutions that can use carvone to store potatoes longer with less need for refrigeration. If it works well, it's a good way to save on both power and harsh chemicals. You can't get more natural than caraway seed and mint.