Why does cut grass smell

Inhale deeply. That heavenly fresh-cut grass smell you savor while mowing your back 40 is actually your lawn screaming in pain from the hell of a hurtful haircut.

Plants and humans respond alike to physical injury by mobilizing our internal pain killers and healing molecules to recover from the trauma, defend our physical system and heal the damage through new growth.

Over the last century, scientists have discovered that grass and other leafy plants routinely emit a variety of vaporous self-defense chemicals called green leaf volatiles GLVs. Specific GLVs act to help leafy plants recover and regrow after being stomped by cattle, stressed by drought, bacteria and pests, chomped by herbivores or clipped by humans with lawn mowers.

Some GLVs even prove to be remarkably proactive. In one study, scientists found that a specific GLV emitted by the coyote tobacco plant interacted with the saliva in certain caterpillars to make the squiggly plant-eaters more appealing to their predators.

So what happens when you mow your lawn? Retrieved November 10, from www. The predator insects that feed on these bugs emit odors that pests can sense, which changes the pests' behavior and Among other things, the insects are a factor in the leaching of nutrients from soil and This method will enable plant breeders and scientists to develop more With insects facing rapid global decline, it is crucial that scientists ScienceDaily shares links with sites in the TrendMD network and earns revenue from third-party advertisers, where indicated.

Print Email Share. Boy or Girl? Can't Find Your Keys? Living Well. Humans don't typically eat turf grass or the insects on it, but the GLVs that grass releases aren't that different from those of plants we do find tasty. That means we have good reasons to be sensitive to them. As far as Baldwin knows, there isn't anything specific to grass that makes it smell nicer to us than another plant. But we are more likely to mow it, injuring a lot of plant tissues at once and releasing a concentrated cloud of GLVs.

With something like 40 million acres People living near tea plantations in China might get the same feeling from the scent of the tea harvest, Baldwin said. Plants themselves can also recognize and respond to these airborne aromas, Baldwin added. If the GLV bouquet indicates that neighboring plants are losing their flowering tops, for example, a plant can shuttle sugar and other resources toward its roots and away from its flowers.