The smell of a freshly mown lawn is uniquely identifiable and for most, immediately brings with it feelings of serenity. It’s a hallmark of the advent of spring and hope for renewal. There is actually some science behind it. According to the Telegraph, researchers at the University of Queensland (Australia), Brisbane have evidence that the aroma may relieve stress and improve the smeller’s memory. And that’s great for us humans — but what about the grass? Getting attacked like that can’t be all that grand.
And, in fact, the tell-tale smell of recently cut grass isn’t meant to assuage our emotions. Rather, it’s the plant’s version of a distress call.
When grass is mowed, it releases a compound called green leaf volatiles, or GLVs, as a response to the damage to its tissues. The GLV release is what causes the distinct smell most of us are familiar with, but it also serves another purpose. Plants can use GLVs as a way to get help from invading insects.
In a 2010 paper published in Science (available here), two researchers — one German, one Dutch — concluded that some plants, while under attack from caterpillars, released GLVs. The GLVs mixed with the caterpillars’ saliva which, combined, results in the emission out a specific odor. That odor, in the case of the wild tobacco plant they studied, attracted certain insects — insects which prey on caterpillars. In some sense, the plant was able to communicate its dire straits to the bugs around them, and successfully at that.
Of course, for grass, the effect is the opposite — if anything, it may lead to more frequent mowings.
From the Archives: Google’s Lawn Mowing Goats: Exactly what it sounds like.
Related: “Picture Perfect: Mowing Techniques for Lawns, Landscapes, and Sports” by David R. Mellor. 4.2 stars on 10 reviews. Not so useful if you live in Greenland.