The colorful leaf scene of autumn every year stretches from the first of September until the first of November. During these two months we witness a slow, almost reluctant, surrender of the green colors to yellows, oranges and reds early in the show. It speeds up greatly as we progress through the days and late summer becomes autumn. Such a long period has many changes, so I refer to these weeks of colorful fall foliage in four phases.
Phase one begins early. As we enter September, a few birches and poplars show an assortment of yellow leaves among the dominating green. The green chlorophyll breaking up within the leaves allows the xanthophyll (yellow) and carotenes (orange) that were mostly present all summer to now be seen. Red maple, sumac, dogwood and the vine Virginia creeper begin the change and use their sunlit sites to make anthocyanin (red) pigments in response to changes inside of the leaves as the sunlight gets shorter. These colors among the deciduous trees will spread as the days of September move on and darkness overtakes the light.
Before this cooling month is over we'll see plenty of autumn colors. The earlier red-turning red maple, sumac, dogwood and Virginia creeper are joined by pin cherry, highbush cranberry, arrow-wood, hazel and some red oaks, especially the younger ones. Other bushes and vines, including raspberry, blackberry, blueberry, bunchberry and even poison ivy, take on this red appearance. With a list like this, it may look as though the yellows don't have much to show and will pale in comparison.
I find, however, that yellows and oranges far outnumber the reds. Trees with this color include birch, poplar, basswood, elm, ironwood, willow, hazel, cherry, juneberry, sugar and mountain maple and numerous other bushes and roadside plants, most notably the milkweed. Sugar maple steals the show from many of the other yellow by blending with a very attractive orange. This phase one will often carry over into early October, depending on the weather, making for a dynamic and scenic September.
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I find early October is phase two, the time when aspens dominate the colors. This tree is abundant in the Northland and its cloning growth patterns. Thick stands demands our attention and takes over the forest scenes when aspen leaves turn yellow.
And then there is phase three. This happens in mid-October, often stretching past Oct. 20 as the yellow-gold of tamaracks glow from the swamps and bogs. Unlike nearly all of the earlier fall colors here, tamaracks are conifers.
Named because they form their seeds in cones, conifers are also known as evergreens. This term makes it sound like they are always green. And indeed, north country pines, spruces, balsams and cedars do keep green leaves, which we call needles, throughout the winter. Tamarack breaks the rules of these trees. Though the leaves are needles, they will shed them during October. Or seen in another way, tamarack (also called larch) is an evergreen that is not ever green, but a deciduous coniferous tree.
In similar fashion of these deciduous trees, the leaves are not just dropped. They go out with bright yellow-golds emanating from the numerous swamp and bogs that we have in the region.
Some of us passersby at this time will need to slow our speed on nearby roads to better observe the colors.
Taking a closer look, we see the needles of tamaracks are borne on the branches in clusters of 15-25. Each is only about 1 inch long, but with so many on the tree, they concentrate the colors.
This wetland wonderland show will continue for a week or two and add a finale to the leaf colors from earlier. The bulk of the broad-leaf deciduous trees drop their leaves at about the middle of October as well, allowing us to see the terrific tamaracks even better.
As we depart this colorful leaf-drop month, the tamaracks join the surrounding deciduous forests in being devoid of leaves as they prepare for the coming months of colder drier weather. But like the other conifers, the small cones remain on the branches. It may be that growing in these wet sites of poor soil that causes the tamarack to differ from other conifers and drop its needles. In the south, the bald cypress, another conifer that sheds its needles, is also a resident of swamps and wetlands.
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Phase three belongs to the tamaracks and is quite a dynamic happening, but some leaf color and leaf-drop is still to take place. Phase four almost seems like an anticlimax, but as we drive the local roads and streets during the final days of this month and even into early November, we'll see plenty of yellows still on two large trees, weeping willows and silver maples. Not as showy as the tamaracks and the earlier deciduous trees, their leaf drop ends the time of leafy trees. We enter the next phase, autwin, after the leaf drop and before the snow cover.
