Our Color-Coded Forest -- v2023

Happy Thanksgiving to readers of Princeton Nature Notes, now 17 years old--the blog, that is, and maybe even some of the readers. I will be leading a nature walk this Sunday, Nov. 26, from 1-3pm, open to all. Meet at the main parking lot for Herrontown Woods, off Snowden Lane. I had hoped to show off what I call the color-coded forest, but a storm of heavy wind and rain stripped most shrubs of their remaining leaves. It will still be good to have a hike, though, and you can see in this post what area woodlands looked like until just a few days ago.

November is when woodlands turn into one of those paintings where you match the color to the number. It's a time when you can gaze into the distance and identify every woody plant by its color. For instance, in this photo of a woodland overlooking the canal in Kingston, check out the yellow in the upper right. That's what's left of the Norway maple leaves, which turn color later than the native maples, and seem to know no other color than yellow in the fall. And the green in the understory? That is bush honeysuckle--what I call the "second forest." It's still green because it evolved on a different continent with a different climate, and so its timing is different from the native flora in spring and fall.

Seen this past week from the cliff in Herrontown Woods, the color coding was much more complex, with non-native Photinia, winged euonymus, and bush honeysuckle mixing with native species.  

Here's a glorious dogwood along the red trail. 

Up on the ridge, the maple-leaved Viburnums develop subtle shadings.

In our "cultural zone" between the Barden and Veblen House, young white oaks turned a rich burgundy earlier in the month. I tell people it's called a white oak because it turns red in the fall. Red oaks mostly turn orange. Naturalists have been doing Stop Making Sense tours long before David Byrne got around to it.

And then there's Photinia villosa, which is both beautiful and concerning, given how densely it has come to dominate in areas across town in Mountain Lakes and the Institute Woods. A few specimens turn bright orange, while

most turn bright yellow, even when growing side by side. You won't see a Norway maple going rogue with orange in the fall.

Another shrub, related to Photinia but just starting to show up in our woods, is a mystery. I discovered it across town fifteen years ago in Rogers Refuge, and even crack botanists have yet to put a name on it. 

Here you can see Photinia (yellow), American holly (evergreen), and in the foreground some sweetgum leaves (red). You can see how empowering the color coded forest is for distinguishing one species from another. 

Barberry is beautiful as well. If only wildlife could feast on beauty, we'd be all set.

Bush honeysuckle--here photographed mid-month with a background of pink winged euonymus--keeps its leaves longer than other nonnatives. Even after all that wind and rain, it could still be easily spotted, clinging to its leaves. 

A less common nonnative called jetbead (Rhodotypos scandens) has found its way into one area of Herrontown Woods near the little red barn. Like bush honeysuckle, it keeps its leaves late into the fall. Having blended in all summer, it suddenly becomes exposed this time of year, thanks to the color-coding.

Small patches of this unusual native grass, found thus far only in a couple spots along the ridge, are easily spotted now as well. 

You can see the long awn on the seed that gives this grass an attractive look, as if it has fancied itself up with long eyelashes. The coppery background leaf is beech, which will keep its leaves far into the winter, a reminder of November's color-coded artistry.

Past posts about the color-coded forest. 

Liz Cutler's Pressed Flower Art

This is a post to honor the work and artistry of one of Princeton's great environmental educators, Liz Cutler. I first knew Liz as founding director of the nonprofit OASIS (Organizing Action on Sustainability In Schools), which promoted sustainability at 23 area schools. As sustainability director at Princeton Day School, she organized school garden tours and climate summits focused on mobilizing and empowering the next generation. Once a year, PDS would send a hundred kids to Mountain Lakes for community workdays back when I was the resource manager there. Later, we served together on the Princeton Environmental Film Festival committee.

Since leaving PDS, Liz says she's been consulting with schools all over the country to help them become more environmentally sustainable. One particularly nice-sounding gig: she spent this past winter as Master Teacher-in-Residence at The Island School in The Bahamas helping their young faculty improve their teaching practice.

To her extraordinary environmental work has more recently been added extraordinary art, specifically pressed flower compositions. According to Liz, what "began as a meditation in 2020 has become a creative manifestation of my love of nature and of my life's work as an environmental educator." 

Less than two years after she started creating her many and varied compositions of pressed flowers, the Princeton Public Library hosted an exhibit of her work. 

She now has a website, LizCutlerPressedFlowers, where she makes prints of her original compositions available for purchase as lasting gifts. The website is an opportunity to check out all her lovely work, and includes a description of her process. Twenty percent of all proceeds go to benefit The Watershed Institute and the D&R Greenway Land Trust. 

The Pleasure and Aesthetics of Native Seed Collection

One of the more pleasurable and aesthetic outdoor experiences in the fall is gathering seeds. I claim no expertise, but adhere to one simple rule: let the stem below the seeds turn brown before harvesting. And harvest when the seeds are dry. Also, be messy. Let some of the seeds fall where they would have fallen if you hadn't come along to take some. Alright, that's three rules. But that last rule is especially enjoyable. How many times in your life have you been told to be messy? 

There are more official rules out there for seed collection, particularly of uncommon species, but nearly all the seeds I collect now are either from my backyard or the Botanical Art Garden, both of which I planted. It's gratifying to see these new populations of local genotypes thriving, and to expand their local presence further. 

The plants I harvest from tend to be generous towards a human tendency to procrastinate. Many species hold on to their seeds for months in the fall and into the winter. But the prettiest time to be picking them is sooner rather than later, as they become increasingly weathered and threadbare as winter progresses.

Harvest of wild senna, seen in the first photo at a lovely stage when the leaves contrast with the dark seed pods, can be postponed considerably, as the pods hold onto the seeds for months.

The bright, fluffy clusters of ironweed seeds are easy to identify on stems that can reach 8 feet.

Rose mallow hibiscus (Hibiscus moscheutos) holds its seeds in convenient cups. Best not to wait too long, because there's a slow attrition to spillage and insects as winter sets in.

As with other sedges, the seed clusters of morning star sedge (Carex grayi) will break apart as fall progresses. Some other local sedges with easily collectible seeds are squarrose sedge and fringed sedge.

The seeds of bottlebrush grass, attractively arranged along the stem, were already starting to fall off when I collected them in late October. Just grab the dried stem between thumb and finger and pull upward to strip the seeds. This is an attractive understory grass. 

The seeds of turtlehead (lower left in the photo) are still ripening, having shown their own form of procrastination, waiting until early fall to bloom.  

Collecting seed has extra meaning and purpose this fall, because many of them will be planted along a wooded slope in Herrontown Woods where a large clone of wisteria had pulled down some of the trees, creating openings where sun can reach the ground. Years of effort, particularly with the consistent, transformative work over the past year or two by volunteer Bill Jemas, has largely snuffed out the daunting wisteria clone that had taken over an acre or two, choking other growth as it steadily expanded along this broad hillside. It even somehow traversed the creek and was headed towards the Botanical Art Garden, adding another layer of urgency to knocking it out. Into the void created by our wisteria removal has come garlic mustard and stiltgrass, but this year we pulled those before they went to seed. 

With much of the slope now bare (the photo shows wisteria to the right, cleared areas to the left), it's time to introduce native plants. We could toss the seeds hither and yon, but I like to give them a better chance by being more deliberate. Deer are an issue, of course, given their appetite for native plants, and my plan is to plant seeds in small circles here and there, creating loci a couple feet wide. I like to scrape a thin layer of dirt away, scatter some seeds, then sprinkle some dirt on top and tamp it down. Then I'll place a 3 foot high plant cage around each circle. Those that grow inside the cage should be protected enough to mature and produce seed that can then scatter beyond the cage on its own in subsequent years. 

It's actually a good way to find out which species the deer leave alone, and which they munch on. We are, in a way, creating "deer feeders" by protecting a few plants inside the cages--plants that each year spread beyond the cages, where the deer can eat them. This approach has been successful at the Barden. Thanks to the town's investment in annual deer culling, many of the plants that sprout beyond the cage survive. 

Of course, all of this thus far is talk. Procrastination is a particularly powerful factor when it comes to getting plants or seeds in the ground. There's so much other work to be done! What's real and lovely, and has actually happened, is the seed collecting. 

The Fiery Look of Prairie Grasses in Fall

These little bluestem grasses (Schizachyrium scoparium), planted in front of town hall in Princeton, looked like they were on fire last week when backlit by morning sun. The last time I saw prairie grasses turn a fiery color in the fall was thirty years ago, when I lived in Ann Arbor, MI. Indian grass and big bluestem would turn bright yellow and orange at the base, making them look as if they were aflame. 

The mimicry of fire was fitting, because prairie grasses are adapted to thrive where periodic fires sweep through. Each fall, when they die back to the ground, they leave above them persistent remains ready to feed a fire. If no fire comes, that persistent dead foliage can get in the way the next spring, casting inhibiting shade on the new growth. 

No fire will sweep through this ornamental planting. Hopefully, someone will imitate fire to some extent by cutting the old stems to the ground next spring so the new stems can grow unhindered.

Little bluestem is shorter and more persistently erect than other prairie grasses like big bluestem and Indian grass, and so fits better into an ornamental planting. Here it is in the courtyard at Maplewood, a nearby retirement facility where our Onstage Seniors documentary theater group recently performed.

And here it is growing near the Princeton University soccer stadium along Fitzrandolph Road, mixed with switchgrass and other native grasses. 

The fiery version in front of town hall was surely a cultivated variety bred for especially dramatic color. But the prairie grasses in Ann Arbor that appeared to be aflame were wild. For some reason, perhaps a milder climate, the same species growing wild at Tusculum or along the gas pipeline right of way in Princeton don't attain that dramatic fall look. 

When I lived in Durham, NC, I often found additional species of native prairie grass persisting beneath powerlines, where they were spared the stifling shade of trees. One that was particularly beautiful when backlit was splitbeard bluestem. Its cottony-like seeds seemed to glow when they caught the autumn sunlight. 

It's good to see native prairie grasses showing up in plantings around town. The university seems to be learning how to maintain them better, which means catching the weeds early. Nice to be surprised by some sideoats grama poking through the fence at the soccer field.