In Eugene, the leaves do not all change at once and they do not all change the same way. By the first week of November the show is usually in its late stage, and the rain is never far from taking a lot of it down. If you have been meaning to go look, do not wait for a perfect weekend. Here is a florist’s field guide to what you are looking at, with the plant facts attributed to Wikipedia’s articles on each tree.
🔬 What Is Actually Happening to the Leaf
Wikipedia’s article on autumn leaf color describes two things going on at once. The leaf loses the green of chlorophyll, and in some species it gains the red of anthocyanins. The yellow and orange you see were in the leaf all along: carotenoids that were simply masked by the intense green of summer. Red is different. Anthocyanins are actively produced in the fall rather than revealed. The trigger is shortening days and cooler temperatures, which start the process of the plant pulling its nutrients back out of the leaf. That is why a tree can look different from its neighbor: each species has its own pigment mix.
🍁 Bigleaf Maple: The Record-Holder Next Door
If you have lived here for more than a season, you have stepped on one. According to Wikipedia, bigleaf maple has the largest leaves of any maple, typically 6 to 12 inches across and occasionally up to 24 inches, and in autumn they turn gold and yellow against evergreen conifers, which is the look we associate with western Oregon. The tree is native to the Pacific coast side of North America, and Wikipedia reports that the current U.S. national champion for size is in Lane County, Oregon: about 119 feet tall with a crown spread of about 91 feet. It also notes that the fallen leaves, blossoms and seeds are concentrated with potassium, calcium and other nutrients, which is one reason to leave leaves under trees and shrubs rather than bagging them all. (That last bit is our own gardening opinion.)
🧡 Vine Maple: The Understory Show
The vine maple (Acer circinatum) is the smaller cousin you find under tall trees. Wikipedia describes it as a many-stemmed, shrub-like tree, most commonly 16 to 26 feet tall, that grows as a low-elevation tree in high-rainfall areas such as the west coast of Oregon. Its leaves have 7 to 11 lobes arranged in a nearly circular pattern, and in the fall they turn bright yellow to orange-red. If you are walking through a shaded wooded trail, look low: the color is often at eye level, not overhead.
🟡 Ginkgo: The One That Drops All at Once
If you see a tree whose leaves are fan-shaped and a deep, even yellow, it is probably a ginkgo. Wikipedia calls its fall foliage a deep saffron yellow and says the leaves turn bright yellow and then fall, sometimes within a short window of one to fifteen days. It is also widely planted in cities for its tolerance of pollution, according to the same article. The practical lesson: if you want to see one at its best, go sooner than you think.
🟤 Oregon White Oak: Honest About Brown
The Willamette Valley’s signature oak does not put on a show. Wikipedia says Oregon white oak is commonly found in the Willamette Valley and that its fall color is “unspectacular,” with many trees turning plain brown. What it offers instead is character. The same article notes that these oaks commonly host a mistletoe (Phoradendron flavescens) in the valley and the round, green or yellow “oak apples” that wasps cause on the undersides of leaves. It also records that oak woodlands were reduced as fire patterns changed after the mid-1800s and as land was converted to farms, and that remaining woodlands are threatened by urbanization and by invasion from Douglas-fir and shrubs. Mistletoe on oaks is a nice fact to have on hand with the holiday season coming. Our guess is that it is easiest to spot once the leaves have dropped, so look up on a winter walk.
🚶 Where to Go Look
We have not surveyed which trees stand where, and we would rather tell you that than guess. What we can say is where Eugene’s old green places are. Hendricks Park is the oldest city park in Eugene, a 78-acre park created in 1906 with mature forest, a 12-acre rhododendron garden and a native plant garden, laced with trails, according to Wikipedia. We wrote about it in our guide to the campus and Hendricks Park. Skinner Butte, the prominent hill named for city founder Eugene Skinner, is the other classic, and our landmarks post has its portrait. For a flat walk along the water, try the Willamette riverbank or Alton Baker Park. Go on a dry day, wear shoes that can handle wet leaves, and leave everything in the park where it grows.
🍂 Bringing a Little of It Home
- Use your own yard. Fallen maple leaves from your own tree make a surprisingly good large-scale accent on a table. A single bigleaf maple leaf under a bowl or vase is a nice runner.
- Press for keeps. Lay leaves flat between sheets of paper inside a heavy book for a week or two. The yellows hold their color better than the reds do, in our experience.
- Pair with real flowers. Gold and rust leaves look natural with dahlias, mums and late roses. If you still have a garden, our before-the-first-frost guide covers what to cut now.
- Add moss and ferns. The forest-floor look in our fern and moss love letter is the same palette as a leaf walk.
- Take photos while the light is low. Our guide to photographing flowers with your phone works for leaves as well.
- When it is done, compost or mulch what you have used.
📋 The Short Version
- Yellow and orange come from pigments that were in the leaf all summer; red is made fresh in autumn.
- Bigleaf maple has the largest leaves of any maple, and the national champion tree is in Lane County.
- Vine maple lights up the understory in yellow to orange-red; ginkgo goes saffron yellow and can drop its leaves within days.
- Oregon white oak, the Willamette Valley’s native oak, turns plain brown and hosts mistletoe.
- Hendricks Park, Skinner Butte and the river paths are good places to walk; leave everything where it grows.