The unofficial fall season is almost underway in Michigan -- which means fall colors are coming.
It’s one of the biggest perks of living in Michigan, watching the leaves change colors and enjoying them with a drive, a hike, or just a seat in your backyard.
So when will fall colors peak this year? It depends where you are in Michigan. According to the annual fall foliage map from SmokeyMountains.com, most of Northern Michigan should start seeing colors within the first couple weeks of September, peaking in mid-to-late September.
For us, we should see partial color change by the second half of the month, peaking in the second or third week of October. And by the end of October, the fall foliage across the state will be past its peak.
Here’s the projected fall foliage timeline for Southeast Michigan:
- Sept. 20: Minimal change
- Sept. 27: Patchy
- Oct. 4: Partial
- Oct. 11: Near peak
- Oct. 18: Peak
- Oct. 25: Past peak
Of course, this is just an estimate, and no tool can predict this with 100 percent accuracy.
Why do leaves change color?
According to Harvard Forecast: Leaves change color during the autumn because the amounts of pigments change as the leaves prepare to fall from the trees. All leaves gradually lose chlorophyll during the growing season, and this loss accelerates before leaf fall. Under optimal conditions this process of chlorophyll loss is very orderly and allows the plants to resorb much of the nitrogen in the structure of the pigment molecule. Carotenoid pigments are also lost from the plastids during aging, but some of them are retained in the plastids after the chlorophyll is removed; this produces autumn leaves with yellow colors. In unusual cases, sometimes in winterberry holly, a fair amount of chlorophyll is left in the leaves when they fall. Such leaves are a pale green in color, or perhaps yellow-green from the mixture of chlorophyll and carotenoids.
Most interesting are leaves that turn red, because this color is the result of the active synthesis of anthocyanin pigments just before the leaves fall from the trees. This is the most common color of autumn leaves; about 70 % of shrubs and trees at the Harvard Forest produce anthocyanins during the senescence of the leaves. In these leaves, the actual shades of red are the consequences of the amounts of anthocyanin, the retention of carotenoids (or even a little chlorophyll). Anthocyanin and chlorophyll produce brownish colors. Anthocyanins and carotenoids produce orange hues. In some plants the color production is quite uniform, as in hobblebush or blueberry. In other plants, leaves vary between individuals (as sugar maples) or even dramatically within an individual (as red maples), or even within a single leaf (red maples).