mix in some sugar
by Nancie Zivetz-Gertler
and the red only deepens
the leaves are changing
A poet with no background in the actual science of trees , writing haiku often leads me to learn unexpected things!
I was working with the kigo “changing leaves” and wondered why the reds are so red, why so breathtaking….
Then I discovered anthocyanins!
Extract from ‘Why do leaves change color in the fall?’:
“Most of the year, these leaves are green because of the chlorophyll they use to absorb energy from sunlight during photosynthesis. The leaves convert the energy into sugars to feed the tree.
As the season changes, temperatures drop and days get shorter. Trees get less direct sunlight, and the chlorophyll in the leaves breaks down.
The lack of chlorophyll reveals yellow and orange pigments that were already in the leaves but masked during the warmer months. Darker red leaves are the result of a chemical change: Sugars that can get trapped in the leaves produce new pigments (called anthocyanins) that weren’t part of the leaf in the growing season. Some trees, like oaks and dogwoods, are likely to produce red leaves.
How much and how fast leaves transform varies by location on the globe. The best colors are produced when the weather is dry, sunny and cool. Places that are cloudy, damp or warm won’t see the same degree of changing color.”
Further reading:
‘Why do leaves change color in the fall?’, 2021, Smithsonian Story, available: https://www.si.edu/stories/why-do-leaves-change-color-fall
‘Autumn splendor: Why do leaves change color in the fall?’, 2017, STEMvisions Blog, Smithsonian Science Education Centre, available: https://ssec.si.edu/stemvisions-blog/autumn-splendor-why-do-leaves-change-color-fall
‘Autumn Views: Art That Captures the Mood, Color, and Light of the Fall Season’, autumnal art from across the Smithsonian, available: https://www.si.edu/spotlight/autumn
Author bio:
Nancie Zivetz-Gertler, a poet and visual artist, studies Haiku in a community of poets with Clark Strand. Her work has been published in Haiku Pause, Tricycle Haiku Challenge, Asahi Haikuist Network, Folk ku, Haiku Avenue and Cold Moon Journal. A recently retired psychotherapist, she lives in Bend. Oregon.
