Changes Coming to Snowden Lane

Snowden Lane has long had a sleepy, rural look on the way out to Herrontown Woods and Smoyer Park. Due to a new development and another one in the wings, that's all changing.

Though it's unfortunate to lose the maples that lined the road, they are making way for a bikeway along one of the more dangerous stretches, as part of a development on 14 acres across from Smoyer Park.

The Friends of Herrontown Woods (FOHW) has been very active over several years to minimize the impact this seven house development will have on the landscape. In return for being allowed to build an extra house, and in response to feedback from the Princeton Environmental Commission, the Shade Tree Commission, and FOHW, the developer agreed to cluster the houses so that 7.5 acres of open space would be preserved. The 7.5 acres back onto Herrontown Woods. Fortunately the developer offered to donate the land to Princeton, and the Friends of Herrontown Woods then worked hard to convince the town to accept the gift.

A detention basin will be built in this spot, to catch and slow down runoff from the development. At FOHW's request, the developer has agreed to plant the basin in native meadow rather than turf grass, which should have all sorts of advantages, including less mowing for the homeowners association.

A public trail will be built from the development down to connect with the trail system in Herrontown Woods. Legal protection of the land does not necessarily mean the land is safe from threats. FOHW is also working with a neighboring homeowner to combat a 2 acre clone of wisteria vine that has been killing trees in the 7.5 acre woodland.

Meanwhile, just down the street, another housing development has long been in the works. FOHW contacted the developer to see if he'd be willing to cluster his houses as well, but it appears the developer is going to stick with a standard plan approved years back.

Stalking Monarchs, and Encountering the Other Milkweed Caterpillar

Note: This post serves as a contrast to the horrific flooding in Houston from Hurricane Harvey, showing how stormwater can drive diversity rather than destruction, if we work with nature rather than against it. Unlike cities, the plants that grow in floodplains are built to pop back up within days or hours after a flood and just keep on growing and flowering. Most of these photos were taken in a detention basin, which is an acre-sized depression in the ground, dug to receive storm runoff from the Smoyer Park parking lot. The purpose is to "detain" the rain that hits the asphalt and that would otherwise rush into the nearby stream. Detaining the water reduces flooding in downstream neighborhoods. The detained water then either seeps into the ground or is slowly released through a small pipe into the stream after the floods have receded. 

Last year, a collaboration of federal and local governments with the Friends of Herrontown Woods converted this mowed basin into a wet meadow with floodplain plant species that thrive with these periodic pulses of runoff. Without regulations requiring it, the concave setting for this lovely oasis for native plants and pollinators would not exist, and the polluted runoff from the parking lot would have flowed straight into the local stream, contributing to flash floods.

Nature has offered up some surprises, here in the doldrums of summer, when people who aren't somewhere else sometimes feel like they should be. There was the unexpected, and unexpectedly affecting, chance to capture family portraits of black vultures in the previous posts; the weather has been unexpectedly cool; rains have come when needed for the third year in a row, and monarchs have proved resilient, rebounding from their diminishing numbers in recent years. Not many, as yet, but more.

Thinking them elusive creatures, I figured a zoom lens was necessary to capture their image. First came a peekaboo shot on the far side of a thistle at the Smoyer Park detention basin that we converted last year to (mostly) native meadow.

The blooms of Indian grass got pleasantly in the way of this shot.

With nowhere else to go in a sea of soccer and baseball fields, the monarch kept circling around the planted meadow, encouraging patient waiting for a chance at an unobstructed view. Finally, a clear shot from 100 feet away, while it perched briefly on a river birch. Congratulating myself on some success with a powerful camera, I plunged into the meadow to weed out a small clump of foxtail grass that would become way too numerous if allowed to go to seed.

And there, five feet away from my tugging and clipping, landed the monarch, easily photographed with an iPhone,

with a coppery background of Indian grass. That's what weeding a wild garden does--it immerses the gardener, creating opportunities for serendipity to work its magic.

Just across Snowden Lane from the park, behind Veblen House where our Friends of Herrontown Woods group has fashioned a clearing by removing invasive shrubs and wisteria, another sort of caterpillar munched on the leaves of common milkweed, which has prospered in the resulting sunlight.

Displaying proper Princeton colors, the milkweed tiger moth needed every milkweed plant there, and then some. We came back a week later and found every milkweed stripped down to bare stems. The common milkweed's strategy of aggressive underground spreading becomes more understandable, given the voracious appetites of these caterpillars.

Also called the milkweed tussock moth, the caterpillars become more colorful as they grow. As an adult moth, they are said to retain the cardiac glycosides they pick up from eating milkweed, and warn bats of their unpalatability by emitting a click as they fly about at night.

With summer almost over, a first sighting of a monarch larvae--on a purple milkweed, of which there are very few in Princeton, for some reason. Common milkweed can be a bit too aggressive in a garden, and swamp milkweed disappeared from our garden after a few years. Purple milkweed with its showy blooms may be a good alternative, if we can find any seed after the hungry caterpillar is done.

Garlic Mustard Pulling Party--Sunday, 10am

Join us this Sunday, June 11 at 10am, before the day heats up, to pull garlic mustard before its seedpods have a chance to burst. We'll have some refreshments on hand, the better to socialize while snipping off the seedpods. Veblen House is up the gravel driveway across the street from 443 Herrontown Rd, or walk up from the main Herrontown Woods parking lot off of Snowden (map here).

We should be able to get all the remaining garlic mustards--half having been pulled last week by volunteers. Garlic mustard is a biennial, meaning it bears seeds the second year and then dies. If we bag up all the seeds each year, the population will fade away, which is good news for native wildflowers we want to reestablish here next to Veblen House.

The first year, garlic mustard looks like this, gathering energy for the seedhead that it sends up the second year. The species was brought to America by European settlers wanting to have something green to eat in early spring, after the long winter. Unfortunately, the plant has very aggressively spread into nature preserves, crowding out native species. Even after several centuries, the wildlife still don't eat it enough to keep it in check.

Another invasive we'll cut back is wisteria. We have almost vanquished an acre-sized, kudzu-like clone of wisteria that just last year was smothering much of the garden and weakening trees. This year's mild followup is really important to starve the roots of any chance to rebound.

Bring hand-pruners and loppers, if you have them, gloves and work shoes. We'll also provide some tools.

Here's a weed we'll allow to grow: moth mullein, a few of which have popped up in the horse run next to the house.

Other projects of the Friends of Herrontown Woods (FOHW) to promote sustainable landscaping include caring for a detention basin at nearby Smoyer Park. The basin was converted from turfgrass to native grasses and wildflowers. FOHW is proactively removing highly aggressive weeds like Canada thistle and crown vetch before they can get established, and adding local native wildflowers like this Hibiscus moscheutos to increase diversity and color.

Seeds for the Spreading

Hibiscus seedheads act like baseball mitts, catching snow in this winter-come-lately weather. There's been some seed collecting this past fall and winter for a couple projects of the Friends of Herrontown Woods. At Smoyer Park, we're partnering with the Princeton Rec. Dept. and Partners for Fish and Wildlife to convert a detention basin to a native wet meadow.

And at the Veblen House, Kurt Tazelaar has been restoring an area where Elizabeth Veblen likely had her daffodil nursery. Over the intervening fifty years, wisteria had spread from the house to climb the trees, obscure the fenceline and claim the sunlight in this woodland opening.

Both of these spots have a combination of wet ground and sun favorable for some favorite native wildflowers that could bring some color to the neighborhood in late summer.

Many of the seeds come from my backyard, which has become a contained riot of local genotypes of cutleaf coneflower,

wild senna,

ironweed, and many others. Leaving last year's stalks up until spring provides cover for our free-ranging chickens, food for the birds, and a superstructure for overwintering insects.

Here's a Eupatorium, with a name only a botanist could love--late-flowering thoroughwort--

and the clustered seeds of buttonbush.

Ironweed seeds have some beauty to them, leaning out over the DR Canal, which was the original source for most of these floodplain species that I've been spreading across Princeton over many years. The canal's sunny openings and lack of past farming provided a place these species could live to bloom another day.

One doesn't need to be near a stream to have floodplain habitat, as many yards around town have low ground that remains wet for long periods, and downspouts create miniature floods of water that can be made to linger in a raingarden. The more places these wildflowers grow in town, the more resilient is the overall population, not only of various wildflowers but also the pollinators that depend on them for food in late summer, when woodlands offer little nectar. Think of it as repopulating the local food desert, ecologically speaking.

Sometimes, seedheads find their way indoors, in this case, Hibiscus and Culver's Root. The Culver's root this seedhead comes from was bought, for lack of a local population.

The slow-release saltshaker-like capsules of Hibiscus moscheutos in early winter, before the seeds have been eaten or shaken out by the wind.

Some hearts a bustin' berries in autumn (Euonymus americanus). A favorite of the deer, only two wild populations of this native shrub have been found in Princeton, both at Herrontown Woods. Because deer find this shrub so delicious, fenced-in backyards become its best chance for reaching maturity.

Monarch Status and Glyphosate, Part 2

As mentioned in a previous post on this year's monarch migration down to Mexico, the weekly migration updates on the Journey North website stopped abruptly on November 11, with the main mass of monarchs still not having arrived in the mountain groves. No more news? What happened? Did the monarchs ever arrive? I emailed the website on Nov. 28, and got a same-day response from an Elizabeth Howard, with this good news:

"We're been waiting for news that the mass arrival has occurred--and just received word yesterday (that it happened the day before). We will be updating the sites soon-- maybe before Monday."

Great, the monarchs arrived, though nearly four weeks later than usual, and I'll feel better when their website is actually updated.

Another communication received, far less friendly, was an anonymous comment concerning the use of the herbicide glyphosate in habitat restoration. Part of the fallout from the massive use of glyphosate on genetically modified "Roundup-Ready" crops has been the demonization of glyphosate and everyone who uses it. The targets of criticism, in some people's minds, should include not only Monsanto and farmers, but also managers of nature preserves who may put a dab of glyphosate on the stumps of invasive shrubs so they don't grow back. Sure, I wrote, in what I thought to be a fairly insightful post, lets rail against the massive use of glyphosate on more than 100 million acres of farmland that once offered monarchs enough scattered milkweeds to prosper. But it's the massive use, not the chemical itself, that is the problem.

Antibiotics provide an analogous situation. Their power can be wisely used in medicine, or abused when indiscriminately given to animals in their feed. It would be unfair to vilify a doctor's careful prescribing of antibiotics because of industrial agriculture's wild excess. And the vilification of preserve managers, who use micro amounts of highly targeted herbicides in their work, is similarly unfair.

Personally, I haven't used herbicides of any kind in years, but any serious attempt to restore balance to a forest, to take on a monstrous, smothering stand of wisteria or thousands of winged euonymus and honeysuckle choking a hillside, will necessarily require some use of herbicide, well-timed and minimally applied.

If the anonymous commenter or anyone else would like to send an email, with name attached, I'd be glad to correspond on this subject. Maybe we can learn something from each other. In the meantime, a hope that the monarchs did in fact arrive and will be safe through the winter.

Another Perilous Embrace--Wisteria and Horse Chestnut

It's almost like someone chose to plant horse chestnuts in front of Princeton's Monument Hall knowing that their blooms would coincide with Memorial Day ceremonies. Here, while taps is being played, one of the first African American marines, Wallace C. Holland, Jr, salutes, and fellow veteran and guest speaker Elana Duffy (under the bell of the horn) looks on.

Meanwhile, elsewhere in Princeton, in front of a home where Thomas Jefferson reportedly stayed when Princeton was briefly the nation's capital, another horse chestnut has less in the way of freedom to celebrate. The blue flowers are of a wisteria vine that's been steadily consolidating its claim to the tree's infrastructure.

From a distance, the scene looks like this, with the wisteria each year adding weight while reducing the tree's access to solar energy to maintain its strength. The effect is pretty, but we'll see how long the tree can take it.

Unlike the American colonies, the tree has no way to free itself of oppression.

Where Vines Tackle Trees

Perhaps we'd suffer cold more gladly if occasionally reminded of how a warmer climate can power unwanted invasions. Our cold NJ winter may, for instance, be knocking back the pine bark beetles that have been moving north into the Pinelands as the climate warms. And we can be thankful that Asian wisteria is not as aggressive here as it is further south. There's a place I used to live, in Durham, North Carolina, where the wisteria grows so densely you needn't touch the ground when you walk. The lateral shoots make a web on the ground,

while the vines reach up and rob the trees of sunlight.

Whole trees collapse, weakened by the weight and lack of sun. The wisteria, which probably started as one small plant brought home from the nursery long ago by a neighbor, has over the intervening decades invaded several acres of woodland that the homes back onto.

Now a 17 acre nature preserve, the woodland displays an exaggerated version of the classic eastern woodland profile--native trees with a mostly exotic understory. Most of the non-native invasives can also be found in NJ, but behave less aggressively because of the cooler climate. Here's a very robust climbing Euonymus, whose hairy stem rivals that of poison ivy.

This tree's branches are actually the lateral shoots of the Euonymus vine.

Elsewhere in the preserve are extensive swaths of Vinca major, English ivy, bamboo and privet, growing so densely that native understory species have little chance of surviving. The preserve was free of Japanese stiltgrass until its seeds hitchhiked in on the tire treads of vehicles brought in to do emergency repair on a sewer.

My friend Perry has been leading workdays to remove the thick stands of privet in this floodplain woods. On the left is before, on the right is after. Invasives removal creates pleasing vistas, safer trails, and sometimes leads to the discovery of a few solitary native shrubs that have been hanging on despite all the competition, such as hazelnut and blackhaw Viburnum.

Herrontown Wood Revisited

It was a walk through the ages, as thirty people came on the first Friends of Herrontown Woods nature walk last weekend, to see the Veblen House and farmstead, and the newly restored trails through the 142 acre tree-and-boulder garden. There were kids, adults, and a cockapoo named Wynston, whose name was claimed to be the only one that rhymes with Princeton.

The walk began with the sound of a pileated woodpecker off in the distance, and there was a rare opportunity to see Kurt Tazelaar sitting down. Kurt--a force of nature, in nature--and Sally (with camera on right), had cleared this trail, which took us past evidence of past quarrying,

and the intimate embrace of trees and rock, as with this white oak. Some time ago, we counted the rings of another white oak that had finally succumbed to a windstorm in this mature section of forest above the cottage, and found it to be at least 150 years old. The trees and the boulders co-led this nature walk, speaking so eloquently of time and endurance.

The boulders got bigger as we climbed the slope of the ridge. Many of the boulders have natural fissures, some of which were broken apart back in the quarrying days. If you look closely, you can see a series of drill holes along the edges,

which Kurt had pointed out earlier. Peter Thompson later sent us a link explaining the stone splitting technique used back in the day.

In some places, the land is pockmarked, as if boulders had been extracted from the landscape like molars, leaving a broad hole in the ground.

How the broken off pieces were transported, and to what use they were put, is part of the unfolding story as Herrontown Woods undergoes a restoration that in some ways is like the restoring of a painting, at once timeless and dynamic. Time will tell if the past's story will be told.

Perhaps some of the quarried stones ended up in this circular horse run--a bit of culture overrun by horticulture, in the form of wisteria likely planted long ago by Elizabeth Veblen.

A major cultural fixture in this wild setting is the Veblen House, which drew lots of interest and discussion about how it could be used for meeting space and nature education. (photo's from a few weeks ago)

The walk benefited from all the collective wisdom assembled. Many came who work to sustain other parks and preserves--Marquand Park, Gulick Preserve, TRI, Mercer Meadows. A couple who had been active with a Friends of Herrontown Woods group in the 1970s came, ready to help with this new wave of energy and interest. It felt good to have Princeton's original nature preserve back in the fold, its arteries cleared and flowing with appreciative humanity once again.

The Color-Coded Forest--Nature's Halloween

This time of year, the forest does its own inverted version of Halloween. Rather than obscuring their identity behind costumes, the trees and shrubs reveal their inner identity. As the chlorophyll fades away, the leaves show each species' true colors, which had been there all along, hiding behind the green facade. These bold declarations make it suddenly easy to identify every bush and tree in the forest, near or far. In this photo, a small sweetgum tree shows its yellow, with Photinia behind it tending more towards brown, and the still green bush honeysuckle rising farther back. Flowering dogwood pokes in some burgundy at the top center of the photo.

Some species are tricky, varying their color depending on location. In front of the Princeton Shopping Center (no photo here), the winged euonymus shrubs lining the old gas station site turn brilliant red in full sun. Given less sunlight, as here, growing at the edge of the woods, they turn a modest pink.

In deep shade, their leaves turn white in the fall.

The native euonymus--Hearts-a-Bustin, which is currently extremely rare locally--also can turn this uncanny, ghostly white.

Very dramatic has been the Japanese maples growing next to the Veblen cottage out at Herrontown Woods, whose condition makes it seem to some a haunted house out in the forest.

The color coding can be useful for surveying the extent of species that are proving to be invasive, like this wisteria that's gone rogue around the Veblen House,

as well as for finding rarely occurring natives like this hazelnut, standing out from the surrounding honeysuckles.

Hazelnuts are real loners. There are three scattered specimens at Mountain Lakes, and only two found thus far in Herrontown Woods and vicinity.