Reference point
A lawn that has just been mown, smelled within the first five minutes.
Do this before you read on. An entry only works when you have just smelled the thing.
Sharply green, cold, with a wet feel, and not sweet at all. It hits very hard in the first few seconds, then falls away quickly.
This smell exists for only about five minutes after the cut, and stops completely as the grass starts to wilt. There is no way to keep it: it is the plant’s emergency response to injury, and the response ends when the plant stops responding.
It is the root reference for the whole idea of “green” in describing smells. When you call a smell green, you are comparing it with cut grass, consciously or not. So it is worth taking the trouble to smell it properly once.
How to smell it
Wait for someone to mow the grass near you, or cut a handful yourself with scissors. Smell within the first two minutes. If there is no grass, crush a few sprigs of coriander or celery leaves — they contain the same group of compounds, though they are not identical. This is a rare entry where you must wait for the right moment; it cannot be done whenever you like.
Why this one is hard
Because the time window is very narrow. Most people smell grass after it has wilted and conclude that the smell is faint. Wilted grass is a quite different smell, belonging to the earthy family rather than the green one.
Don’t confuse with
This entry
Cut grass
Green family
The same plant, a few sunny days apart. Fresh grass is sharp, green and cold; hay is sweet, warm, vanilla-like and stays for a very long time.
Scientific note
The compounds behind this smell are called green leaf volatiles: six-carbon aldehydes and alcohols released when cell membranes are broken. They are a signal the plant gives off when it is eaten or cut, and some parasitic wasps use that very signal to locate caterpillars feeding on the leaves. What you smell on a quiet afternoon is really a call for help, and something is listening.
In Vietnamese life
In Vietnam the smell of freshly cut grass goes with schoolyards at the start of the school year, park lawns early in the morning and field edges in the weeding season. It is also one of the most imitated smells in room sprays and laundry products — the synthetic version is usually much sweeter and longer-lasting than the real one, because the real one lives only a few minutes.