Photo by Robin Plaskoff Horton

Almost like the passing of a torch from one season to the next, these autumn leaves left their impression on the concrete sidewalk as if to say, “I was here, and I will be back. Adieu!”

So I wondered, how do these phytoprints, these hints of foliage, get left behind? With a little research I found that it is the tannins in the leaf–just like the tannic acids that give tea its color–that allow the leaf to bequeath its signature on the sidewalk. Depending on the type of tannin, they produce different colors–either blue, blue black, or green to greenish black.

” Tannins are responsible for the brown hues in the leaves of some oaks and other trees,” according to the Butler University Friesner Herbarium website. “The golden yellow in some leaves such as beech are a result of tannins being present along with the yellow carotenoid pigments.  These compounds are always present in the leaves, but only become visible as chlorophyll ad carotenoids disappear from leaves.  Tannins are bitter substances responsible for the color and flavor of tea.  They are common waste products of tree metabolism, deposited in the cell sap inside the vacuole as well as in cell walls.”

These leaves are bidding us goodbye…the last vestiges of autumn left on the ground as a hint of their return next spring.

Make Your Own Leaf Prints
1. Paint the underside of the leaf and stamp it to fabric such as muslin or burlap. From that fabric, you can make seasonal pillows, place mats, a table runner, or just a print to hang.
2. Collect a variety of different colored leaves and glue them to contrasting colored papers. Try high gloss finishes or metallics to really highlight the leaves.
3. Hammer leaves onto a piece of muslin or other light fabric allowing the natural dyes to leave their impression in the fabric. Place a piece of paper towel or wax paper over the leaves when you hammer.
4. When doing these projects with children, talk about the kinds of leaves and explain how the leaves the change color. You can discuss how natural dyes are used. (Tanning leather utilizes the wood tannins from oak ((from the word tanna, an Old High German word for oak or fir tree, as in Tannenbaum.)