I spotted the first Dark-eyed Junco in my garden on a Sunday morning. I had noticed the dapper, little gray-backed birds skipping along the ground around town the past week. I am thrilled that they have returned to my garden.
The Juncos signal that cold weather and winter are near. They leave in the spring for their breeding grounds far to the north in the boreal forest.
They migrate south to warmer winter areas like Philadelphia in late fall and stay until spring. The birds arrive here as the Shadbush is in its full peak of color in the fall.
I use the Shadbush (also called the Common Serviceberry) as an “indicator” plant. When I notice something happening I want to make note of, I use the Shadbush (Amelanchier arborea), growing in my backyard as a marker of time. This is basic phenology, the study of seasonal occurrences and correspondences.
The Shadbush gets its’ name because, as its flowers are blooming, the Shad fish are on their annual migration from the ocean, up inland rivers to its breeding grounds. The inland rivers, like Philadelphia’s Schuylkill and Delaware Rivers are a passageway for thousands of fish. Humans fish in the Schuylkill River for food and the Philadelphia Water Department works hard to keep the Schuylkill River clean. At this time the Shad is in abundance. The shad is a bony but tasty fish and was my grandmother’s favorite.
Any plant you choose can be your personal ‘indicator’ plant. I chose a native plant that was close to home and that I would see every day. The shadbush lives in my garden and is visible from my bedroom window.
I can see this small tree as it grows from bare winter branches to first bud to full bloom, to fall color and leaf drop and back to bareness again.
I like using trees and shrubs as my indicator plants as they are less likely to move from year to year. I think good indicator plants could be any of the oaks, maples, nut or berry trees and shrubs. I like using food plants because it teaches me useful survival skills.
If I choose an oak, I would choose a ‘white’ oak. White Oaks leaves have rounded edges. White oaks have sweet acorns which mature in one season and can be eaten raw. Red oaks (with pointed leaves) need two years to mature and the acorns require soaking in water to remove the bitter tannic that can cause constipation if eaten. Acorns can be ground into flour and used to make cooking oil
I think good indicator plants would be White Oak, Sugar Maples, nut trees (hickory, walnut, hazelnut, beechnuts, etc.) and berry shrubs like blueberry, shadbush, chokeberry or cranberry).
Watching indicator plants and learning correspondences is a way of developing deep ecological knowledge and relearning the skills that sustained our ancestors for thousands of years.