The April winds in my area are strong at times, ushering in both sun and rain. In my runs and bike rides through the neighborhood, the air temperature is noticeably warmer. The warmer air brings with it familiar aromas of spring.
While biking on one of the sunny days this past week, the sweet, intoxicating aroma of fresh cut grass filled the warm air. A hint of freshly spread hardwood mulch was also present. It has a pungent yet sweet distinct aroma that I know all too well from my days working as a landscaper.
The smell of fresh cut grass is a response to the trauma inflicted upon the grass when cut. Volatile organic compounds called green leaf volatiles (GLFs) are released by the plant in high amounts. The release of these natural chemicals serve multiple purposes including:
- Stimulating the formation of new cells to help close the wound
- Acting as antibiotics to prevent bacterial infection and fungal growth
- Spurring defensive compound production at wound sites
- Reacting with other chemicals to act as distress signals
Wood mulch obtains its aroma from the decaying process. The word mulch is derived from the Old English melsc or mylsc, which means soft or mild. The mulch becomes soft in the decaying process, releasing chemicals similar to the volatile organic compounds found in grass.
Posies in the Air
Other aromas I have detected in the past few days include:
- The distinct, pungent odor of skunk cabbage, which grows on my property along the creek bed
- The sweet, light smell of hyacinths in the landscape bed beside my sidewalk
- The strong yet sweet scent of daffodils in my landscaping
- A mild hint of lilac from the still closed buds on the bushes around my yard
Thursday morning, I stepped outside and smelled the rain coming in the distance. As the rain fell, the air was filled with a fresh, earthy smell, as if nature was washing the atmosphere. While biking past a neighbor’s farm, the smell of freshly plowed soil and earthworms permeated the air. I also noticed many of the worms crawling on pavement and sidewalks along my route.
Smells Like Spring
All around me, smells of spring permeate the air. Some smells are more distinct in the sun, others in the rain. In either case, these smells evoke thoughts of spring and all the changes that come with the season.
Resources and Related Links
Daffodils – http://daffodilusa.org/
Earthy smell – http://www.livescience.com/49520-smell-of-rain-aerosols.html
Green leaf volatiles – http://www.sciencedaily.com/releases/2012/10/121016103917.htm
Hardwood mulch – http://www.ladybug.uconn.edu/factsheets/tp_05_mulchbasics.html
Lilacs – http://www.almanac.com/plant/lilacs
Mulch derivation – http://www.oxforddictionaries.com/us/definition/american_english/mulch
Smell of fresh cut grass – http://mentalfloss.com/article/30573/what-causes-fresh-cut-grass-smell
Smell of rain coming – http://www.livescience.com/37648-good-smells-rain-petrichor.html