April 14 Event: Walks Across Princeton

Whether you know and love Mountain Lakes, or have somehow managed to remain unaware of Princeton's "central park", Saturday April 14 would be a great time to visit.

The Friends of Princeton Open Space--the quiet nonprofit that has done so much to preserve and manage nature preserves in Princeton--will host a series of walks on April 14 to celebrate Princeton's natural areas.

Three guided walks of differing lengths will be offered, all of which plan to converge at Mountain Lakes House at 2pm for refreshments.

The event is free and all are welcome. To register or get more info, go to fopos.org.

Lesser Celandine Blooming, But Mostly Spreading

 I wish I could go back to the first time I saw this flower and could appreciate its beauty without being worried it would take over all of Princeton. At Pettoranello Gardens it grows like green pavement next to the paths, blooms beautifully, but is radically invasive. Since becoming established at Pettoranello Gardens, it has spread downstream and has now become established in floodplains at Mountain Lakes Preserve. It displaces native plants, is apparently inedible to wildlife, and though it's pretty for a couple weeks, the rest of the time it's busy making natural areas less supportive of plant diversity and wildlife.

 In a suburban yard, it first appears as a couple plants, with small, roundish, shiny leaves.

It displaces the grass over time, then dies back in late spring to leave bare spots in the lawn. Its many underground bulbules make it hard to eradicate by pulling.

Lesser Celandine has started to show up in my former home of Durham, NC, where I've been trying to help eradicate small populations before they spread downstream.

Planting the Shore

If St. Patrick's Day is the traditional day for planting peas, then March 8th must be the traditional date when rushes are planted next to a pond. The dredging of the upper Mountain Lake in Princeton left the shoreline bare. A fence effectively kept the geese from congregating, but didn't quite do the trick appearance-wise.

FOPOS board member Tim Patrick-Miller at some point realized that the solution was growing just downstream, where thousands of native rushes and sedges had sprouted in the drained lakebed of the lower lake. Clark Lennon and Tim are working with new FOPOS natural resources manager AeLin Compton to transplant the natives along the shoreline.

Soft rush (Juncas effusus) is a very tough native plant whose evergreen stems and vaselike shape give it an ornamental appearance once it's established.

Update on Dam Restoration at Mountain Lakes

I haven't heard anything official, but it looks like the lower dam at Mountain Lakes Preserve is nearly complete. The wooden posts in the foreground mark where a ramp once was located for hauling chunks of ice out of the pond and hoisting them into the 3-story ice barns that used to rise behind the dam to the right.

The ice operation closed down around 1930, as refrigerators became more widely available. The stone wall extending the length of the dam is completely new, designed to mimic the original wall that now lies buried under the expanded earthen portion of the dam. For safety reasons, the dam is now broader and several feet higher than previously.

At the other end of the dam stands the newly restored spillway. As far as I know, the informative signs that were there prior to restoration will be reinstalled, describing the decades during which Mountain Lakes supplied Princeton with ice for its iceboxes.

Meanwhile, upstream of the two Mountain Lakes is another dam that was added onto the project, funded by the same anonymous donor. I had long argued in favor of restoring this "upper settling pond", also known as North Pond--an argument that was going nowhere until funding became available. It's located on one of the two tributaries feeding the lakes, and was built in the 1950s by the Clarks, who also built Mountain Lakes House around the same time.

The pond is called a catchment basin for good reason. Water rushing downstream from Witherspoon Woods drops its sediment in this pond, thereby greatly reducing the amount of sediment that would otherwise have continued into the Mountain Lakes. It played this role very effectively, completely filling up over the past 50 years. There must be 8 feet of very rich sediment here, which this week is being trucked away, perhaps to a topsoil business.

With the catchment basin trapping sediment, at least on that one tributary, the upper Mountain Lake will last much longer before it once again will require dredging.

This is my favorite vista, standing at the northwest, upstream end of the lakes, looking down.

In Death, a Long Life

A big white oak, veteran of many storms, finally met a windstorm it couldn't match.

All its sprawling limbs came crashing down, leaving the trunk as a monument to its long and acornful life. The monument even bears its name on a label attached fifteen years ago as part of an eagle scout project.

One limb decided to patronize a heavyduty picnic table--those old tables that loom like lost battleships in the overgrown woods at Community Park North, strong enough to last for centuries but so uninviting and misplaced they never get used.

The tree was hollow, and last year rather gruesomely sported a raccoon that had sadly gotten stuck trying to exit through a hole 15 feet up.

Now, in its long life after death, it will begin the slow return to soil, sheltering and feeding life of all sorts in the process.

Ring-Necked Snake

Why did the Ring-necked snake cross the road?

Answer #1: Because the habitat is always greener on the other side.
Answer #2: So it could learn its name from a biologist passing by.

Thanks to Tim Anderson, environmental science teacher at Princeton High School, for the photo and email below. There's long been talk of putting "Turtle Crossing" signs along the driveway up to Mountain Lakes House. Here's another denizen of the woods whose wanderings sometimes intersect with asphalt.

"Biking up the road to the house at Mt. Lakes, ran into a couple trying to help a juvenile snake cross the road...It was so small we couldn't pick it up with fingers...but got it off the road while a car waited to pass.  It matches this northern subspecies picture of ring-necked snake juvenile. It was about this size too." --Tim

Princeton Day School Community Day at Mountain Lakes

On September 16 at 9am, 100 PDS 9th graders arrived at Community Park North ready to help remove invasive plants, as part of the school's annual Community Day. First step was to buddy up with 4th graders who had also made the hike over from their school.

After a brief intro by yours truly about plant identification, the why and the wherefore of invasive plant control, and some tips on how to use loppers, saws and garden rakes safely, they set about the day's task.

Neither the thorns of multiflora rose nor the sheer numbers of invasive shrubs crowding the woods could deter them from their newfound mission. Those with loppers cut honeysuckle, privet and multiflora rose, while others hauled the cuttings into brushpiles, to serve as habitat.

What I particularly enjoy is showing the kids how to work together, use the tools most effectively, and how to get into a steady working rhythm so that a lot can be accomplished. After a morning's work session, they could see the difference they had made.

Native shrubs intermixed with the exotic invasives had been tagged beforehand, and left uncut to take advantage of the additional sun and water available now that the exotic competition had been removed. In the photo is spicebush (Lindera benzoin), which the kids discovered gives off an appealing fragrance when the leaves are scratched. That natives will fill the void left by the removed invasives helps make clear the positive impact of the work.

An innovative method of transporting litter was developed when some of the kids went back out to pick up stray tools.

During the lunch break, volunteer Andrew Thornton engaged the kids in some juggling.

After lunch, I led the 9th graders on a tour through the 400 acres of preserved land in and around Mountain Lakes. Like so many Princetonians, the majority of the kids had never seen Pettoranello Gardens, the evergreen forest, or the historic fields of John Witherspoon's Tusculum. (the area we worked on is in the lower right; PDS school is in the upper left)

They walked past trees stripped of their limbs by Hurricane Irene,

clambored across a bridge washed askew by the recent flooding,

and past construction to restore the lower dam at Mountain Lakes.

At one stop along the way, a student asked why it's called Mountain Lakes if there are no mountains nearby. I explained that Princeton bestows its ennobling magic on all within its borders, making ponds into lakes and hills into mountains. These words having been spoken, I am sure that all within earshot gazed out upon the landscape with new eyes.

When they reached the turn leading to their school, they disappeared up the trail, their good deeds done and another school year begun.

The Friends of Princeton Open Space thank the students and teachers of Princeton Day School for their contribution to restoring habitat in town.

Thanks also to community volunteers Andrew Thornton and Tony Beesley for helping out with supervision.

Surprises Along the Boardwalk

When the township, with the help of a grant from the J. Seward Johnson, Sr. Charitable Trust and considerable initiative by the Friends of Princeton Open Space, built the long boardwalk below Coventry Farm, it provided a convenient link from the Great Road and Farmview Fields Park over to Mountain Lakes Preserve. From a botanist's point of view, it seemed moreover a great place to show off native wetland plants. The boardwalk extends three feet high over a corridor typically kept wet by seepage from Coventry Farm. Unfortunately, early planting efforts fell victim to the smothering growth of an invasive plant called reed canary grass, here seen growing over the edges of the boardwalk like a green wave.

On a recent visit, however, a few self-planted native wildflowers were found holding there own in spaces left open by the reed canary grass. Here's some arrow-leaved tearthumb, so called because its stem is raspy if you run your fingers down it.

Moths grazed on a goldenrod.

Virginia creeper imitated topiary on a fencepost.

An elderberry bush showed promise of providing edible berries in years to come.

Clumps of ironweed were about to add purple blooms to the picturesque view.

A prairie grass called purple top gave the meadow a colorful sheen at the Great Road end of the boardwalk.

Most intriguing was a clump of boneset. Type "boneset" into the search window at the upper left of this webpage and you'll find many posts documenting the seemingly endless variety of insects and spiders that take up residence for the month of August in its miniature metropolis of white flowers.

This particular boneset did not disappoint. A close look at the center of this photo holds a surprise--for people as well as a hapless wasp that had been feeding on the nectar.

Waiting just under the flowers was a praying mantis, which had grabbed the wasp and was now enjoying its lunch. The accumulation of wasp legs on the leaf below suggests the praying mantis is particular about which pieces of the anatomy it consumes.

Heading back towards Mountain Lakes, the seeds of green bulrush,

and the prospect of a fine picnic for humans in a week or two.

A Walk At Mountain Lakes

Recent walks through Mountain Lakes led us down paths paved with path rush, a short, dark-green grass-like plant that survives foot traffic better than other plants.

Close up, it has this squashed, angular look.

Usually, stopping to smell the roses proves to be a forgettable experience, given that fragrance has been bred out of most roses. But the swamp rose has escaped the breeders and rewards anyone who wanders into the low, wet, sunny places where it grows.

Common milkweed is another wildflower that survives where trees have not claimed all the sunlight.

We also found a fox grape (Vitis labrusca), that had some very promising-looking berries developing. For identification, it helps to look at the underside of the leaf, which is white/tan instead of green. Concord grapes are bred from fox grape.

We also saw a hazelnut shrub that is kindly donating a portion of its leaves to the food chain.

Part of gaining some woods savvy is learning to recognize poison ivy in all its forms. Here, it has grown up the side of a pear tree next to the creek. The poison ivy "trunk" is hairy, which rhymes with scary, while the horizontal rows of holes on the trunk of the pear tree speak to past visits by sapsuckers. I'm not actually touching the poison ivy, but if I did I'd rinse my hand off in the creek within twenty minutes or so, to avoid getting a rash.

Head downstream from Mountain Lakes and you eventually reach the long boardwalk to the Great Road, where a smaller kind of grape framed a view of Coventry Farm.

Where the lower dam is being rebuilt, we were hoping to see the old ramp, recently discovered, upon which the big blocks of ice were hauled up into the barns in the early 1900s (see earlier post), but the artifact has been covered with a tarp, in preparation for reburial. The best way to preserve it, reportedly, is to cover it up again with muck and lake water.

Princeton Bible Church Brings Their Green Project To Mountain Lakes

Many thanks to all the members of the Princeton Bible Church Green Project who came to Mountain Lakes yesterday to help with removal of invasive shrubs.

Andrew Thornton (right) helped show everyone which shrubs were exotic and needed to be cut.

Four hours of steady effort with loppers and pruning saws cleared a large swath of exotic understory beginning at the Mountain Lakes House parking lot

and continuing down the slope to the lakes.

 Our youngest helper, after carrying some sticks to the brushpiles volunteers made for habitat, took a great interest in all the clipping going on.

This spring, inspired by the ongoing restoration of the dams and lakes by Princeton Township, and all the updating inside and outside of Mountain Lakes House, we're focusing on restoring habitat on the slopes surrounding the lakes.


Exotic shrubs cut: honeysuckle shrub and vine, privet, Asian photinia, and the occasional Linden viburnum and barberry.


Native shrubs and small trees left to grow: Blackhaw viburnum, sassafras, flowering dogwood, silky dogwood, false indigo.