Thursday, June 30, 2022

Weeding Princeton's Fuel Tank Raingarden

When neighbor's complained about the appearance of the fuel tank on Witherspoon Street, the town responded by removing the fueling station's roof, adding a brick facade, and planting the raingarden that had been built to catch and filter runoff from the pavement. 

With the raingarden looking good in its first full year, the intended plants tidily mulched and flourishing, you'd think that it's time to sit back and enjoy nature's beneficence.

But as a gardener who has seen many a raingarden succumb to weeds, I could not help but notice the first signs that a silent, weedy insurrection was in the works. Here is a small patch of mugwort, planning a rhizomatous takeover.

Here's another little, harmless-looking cluster of mugwort next to a lovely St Johnswort shrub. And what's that grasslike plant in the background? That would be nutsedge, easy to pull but also with an underground network of roots that is hard to exhaust. If allowed to grow, it too will spread everywhere. 
The weeds look harmless when there are just a few, but a gardener can extrapolate in the imagination from a little to a lot. I couldn't help myself, and intervened. How many gardens are at such an early stage when thirty minutes of weeding can nip invasion in the bud? Here are horse nettle, mugwort and nutsedge. Feel for the triangular stem on the nutsedge. "Sedges have edges."

Here is white clover, which is benign in a lawn but muddles things in a flower bed.
On the left is a vetch, not crown vetch thankfully, but still worth pulling. 

I pulled pretty much every weed except the nutsedge, whose takeover will hopefully be forestalled by the designated caretaker, if any. Afterwards, the raingarden looked to most eyes exactly like it had a half hour prior. The reward of proactive action is in imagining all the future work that has just been avoided. There will be more work, surely, but much less. 

Maybe someone with designated responsibility would have done the weeding anyway. Nice to think but hard to count on. 

Meanwhile, on the other side of the new fire station, another raingarden was planted at some point. Lots of good stuff growing, but much more intimidating in terms of weeds. It shows what happens when the weeds are allowed to gain a foothold.

The pink is crown vetch, an aggressive plant originally introduced to the U.S. to control roadside erosion. 

And then there's birdsfoot trefoil, originally introduced to the U.S. as nutritious forage for cattle.

And relentless bindweed growing up and over the native swamp milkweed. 

Subduing these three tough customers would take some major work, which makes it all the more amazing to be able to weed the other raingarden and feel like one has the upper hand. 

All of this leads to a point, or two, made before, that regulations require the planting of raingardens in the name of reduced flooding and increased water quality, yet maintenance operations are set up to handle only the simplest of landscapes--turf and trees. Raingardens are a complex community of plants, not a monoculture. They don't respond well to "mow, blow, and go." The person who cares for them needs to be more physician than custodian. They can be planted by people who don't really know the plants, but they need to be cared for by people who do, in a culture that devalues informed maintenance. 

Active Trees and Passive People

Each year about this time, I watch as low hanging tree branches extend over sidewalks. It's a bit of a game, to see how long it takes for anyone to do anything about it.

In fact, no one does anything about it. Instead, people just keep ducking down deeper and deeper as the branches grow. Finally, I get fed up, find some loppers, and go out and clear the route. There were three of these low spots on my block. A few minutes of intervention will save thousands of bendings over through the summer, and maybe keep a distracted bicyclist from getting whiplashed. 

The vast majority of people remain enduringly passive when navigating collectively owned spaces. Or maybe no one else owns a pair of loppers.

Tuesday, June 21, 2022

Black Bear Seen in Princeton

 This notice from the University:

Date:  Monday, June 20

Incident:  Black Bear Sighting

At approximately 2 pm. on Monday, June 20, a black bear sighting was reported on the Lake Campus (300 Washington Road).

Black bears by nature tend to be wary of people.

The New Jersey Department of Environmental Protection has tips on black bears available at

A compendium of previous black bear sightings can be found by typing "bear" into the search box for this blog. They include an explanation of why black bears come wandering our way this time of year, which has to do with young males seeking new territory.

Many people wonder how to behave when a bear is encountered. Below are the fruits of my research, conducted ten years ago and adapted for a Princeton audience. These words are as relevant now as they were then. Please note that grizzly bears, which are not found around here, require a completely different response.

Black bears are near-sighted, so make noise to avoid surprising them. If the bear stands up on its hind legs, don’t worry. It’s just trying to see you better. Make sure the bear has an escape route. For instance, if it is following you out of the public library, hold the door open and give it plenty of room. If you encounter the bear in the woods, or on Nassau Street, you can back away slowly, but don't turn your back to the bear. In a calm, assertive voice, put the bear on notice that you are a Princetonian fully armed with opinions, and will not hesitate to express them.

Avoid eye contact. If it doesn't run away right off, bang the pot you happen to be carrying with you, or download a "kitchenware noise" app on your cellphone. Bears hate to cook, which explains their interest in garbage. Otherwise, clap your hands, raise your arms over your head, wave a jacket, all of which should make you look large and impressive.

On rare occasions, the bear will do a bluff charge, at speeds up to 35 mph. If a cafe is close by, this is a good time to duck in for a double latte. If that option is not available, then you'll need to dig deep. Fleeing will only make you appear weak. Perhaps the stirring words of a high school football coach will come to mind. In any case, stand your ground, wave your arms and shout. Pretend you're in front of town council, venting your outrage over moving the Dinky. The bear should veer away from you at the last moment, providing a bigger thrill than any 3D movie at the mall.

If the bear actually attacks, which is extremely rare, it's time to drop all remaining pretense of civility. Fight back. Don't worry about the bear's lack of access to dental care. Without asking permission, bop it on the nose. Bears' noses are 100 times more sensitive than ours. Use this sensitivity to your advantage, all the while reveling in what a great story this will make to tell the grandkids.

Note: In case you surf the internet for more info, don't be confused by accounts of how to behave when encountering a grizzly bear out west, where the protocol is completely different and not nearly so gallant.

Saturday, June 11, 2022

The Unbearable Whiteness of Being in June

Note: The memorable title "The Unbearable Lightness of Being" may not be as fresh in people's minds as it was in the 1980s when the novel and subsequent movie came out. There's nothing unbearable about white flowers, but there sure are a lot of them this time of year.

It was on a recent walk along the green trail at Autumn Hill Reservation that I suddenly noticed I was surrounded by white. 

Mostly, it was invasive species: the white of multiflora rose
and Linden Viburnum. The prompt for the walk was to check the trails. The Friends of Herrontown Woods takes care of the trails at the adjacent Autumn Hill, and this spring's intervention was a boardwalk spanning a section that for years had been chronically muddy. The town's open space manager, Cindy Taylor, got the town crew to help out by removing some fallen trees, and I was checking to see if anything else was needed.

Though the nonnative shrubs were the dominant flowers, a few natives could be found, also with white flowers. A cluster of partridgeberry hugged the ground. The "repens" in its latin name, Mitchella ripens, refers to its crawling habit.
The mapleleaved Viburnums usually don't grow beyond a few feet. Their latin name is Viburnum acerifolium. The latin name for maples is Acer, so acerifolium is the latin way of saying maple foliage, or mapleleaved. 
Almost missed among all the whiteness was a beautiful specimen of Styrax, probably American snowbell, S. americanus. It's on the left as one pulls into the Autumn Hill parking lot. My guess is that it was planted. I've walked by it dozens of times, but only when it flowered did I take note. That makes a grand total of two of this species seen thus far in Princeton.

Back home, there was the mock orange-a once commonly planted landscape shrub that survives in my neighbor's yard, peeking over the fenceline.

More whiteness comes from the native elderberry, whose berries make delicious pies if you can beat the catbirds,
and the abundant spires of Virginia sweetspire.
The mountain laurel

and the Deutzia in our yard are refusing to grow beyond one foot high for some reason.

White clover can be benign in a lawn but mischievous if it invades a flowerbed.

Update: Ten days after initially posting about white flowers, and feeling like the title of the post, though playful, sounds more judgemental than it would have ten years ago, I've noticed a few more. The Korean dogwood, for instance.
and catalpas, whose flowers reward a closer look.
Japanese honeysuckle, which yield a drop of sweet liquid if pulled apart in the right way.

Some sort of hydrangia vine on our patio.
The flowers of a native swamp azalea. They look to be keeping their flowers downcast, as if to avoid eye contact. Too many zoom meetings.
A small patch of daisies in a preserved pasture near Veblen House.
A white cloud of daisy fleabanes in the foreground, with an oak-leaved hydrangia in the background. 
This oak-leaved hydrangia, native though I've never seen it growing in the wild, started as one plant, but over time it produced stems that could be dug without disturbing the original plant. We now have a whole grove of them.

The oak-leaved hydrangia is one of three classic native shrubs that sustain white in the garden through June, as Virginia sweetspire (above) segues into oak-leaved hydrangia,
which segues into the bottlebrush-shaped spires of bottlebrush buckeye. 

Why so much white? My curiosity did not sustain me very far into an internet search. Perhaps white takes less energy for plants to produce than other colors. White reflects the most light, which could help insects find it. And then there's the research that shows that pollinators don't actually see the flowers as white, and are picking up on aspects of the flower beyond human perception. 

Below is beardtongue having a good year in the Veblen Circle of wildflowers at the Barden in Herrontown Woods. 

Monday, June 06, 2022

Shrubs and Vines to Cut Back Along Nature Trails

Without volunteers wielding clippers and loppers, most trails in Princeton would quickly become overgrown. Some preserves, like Mountain Lakes, Herrontown Woods and Autumn Hill Reservation, have more organized maintenance, but in some others it's catch as catch can. In May and June, that first flush of growth begins reaching out over trails, and so a pair of clippers is handy to keep in the back pocket during a hike. Cutting back anything that overhangs a trail is useful, but as a botanist I'm also identifying as I go along. Most of the shrubs that grow out into trails are invasive species that we'd want to cut wherever they are growing, but especially along trails. There are also some natives, but I'll start with the non-natives, which are so numerous mostly because the deer won't eat them. 

Privet -- A shrub that people plant as hedges, but which has spread into nature preserves, establishing dense stands. In low, wet, shaded areas, there can be thousands and thousands of these, claiming all the space. Most don't bloom because they are too shaded.

Here's a typical branch of privet growing out over a trail. 
Linden Viburnum has become highly invasive, forming dense stands. It has attractive flowers and fall color, but is just way too aggressive. It looks a lot like the native arrowwood Viburnum (V. dentatum), which is relatively rare and has more deeply toothed leaves. 
We commonly call this shrub Photinia, after its latin name. You can identify it by its distinctive obovate leaves, meaning the leaf is wider towards the tip. Names can get complicated in botany. The common name, which I just learned, is Christmas berry. The latin name was Photinia villosa, but that got changed to Pourthiaea villosa. Can you say "Pourthiaea"? Neither can I. In any case, it is another way-too aggressive nonnative shrub that we cut back or down.
This shrub, winged Euonymus, is super easy to identify. Just look for the "wings" on the stem (those brown ribs that run along the stem). It, too, is a nonnative that forms dense stands and often obscures what would otherwise be lovely vistas from the trail. If you see a nice vista from the trail, oftentimes it's because we've been cutting these shrubs down to open up the view. 

A common story about native plants in the wild: there's a native Euonymus, called Hearts-a-Bustin', but it's rarely seen because the deer love to eat it. We've nurtured a few specimens of it to show off at the Barden.

Bush honeysuckle -- Honeysuckle comes in the form of a vine (Japanese honeysuckle) and several species of shrub. it is frequently found along the edges of people's backyards--a sort of default vegetation that moves in on its own. It can also be numerous in some of Princeton's preserves.

Wineberry is an asian species of bramble with distinctively hairy reddish stems. It has tasty berries, but we often cut or pull it, given its lanky, thorny growth.
Autumn olive has a distinctive silver sheen on the underside of the leaves. While many invasive shrubs thrive in shade, autumn olive prefers sun, and so is infrequently encountered along our wooded trails.
Multiflora rose is an introduced species that has made many a forest impenetrable with its curved "fishhook" thorns. Multiflora means many flowers clustered together, as opposed to the single flowers that many roses have. We definitely cut this one back, or down to the ground, to keep hikers from getting snagged. 

Our native roses--at Herrontown Woods, that would be the very rarely encountered swamp rose--have single pink flowers, as opposed to the multiflora's clusters of white.
If you forgot your clippers, it's possible to avoid the thorns while carefully bending a young sprig like this one back on itself with your fingers until it snaps.

Two nonnative vines we pull out along trails are the Japanese honeysuckle 
and oriental bittersweet. Both are easily pulled out. For more success in pulling them out, grab low and pull slow. 

There are native versions of vine honeysuckle and bittersweet, but never encountered, as far as I know, in Herrontown Woods.

A common native along trails is sweetgum, which can grow into a statuesque tree but which we tend to cut or pull along trails, since its seedlings are so numerous.
The most common native shrub is blackhaw Viburnum, which has tasty berries in the fall. Sometimes it can be distinguished from other shrubs by its pairs of tiny leaves tucked in among the larger leaves, growing tight against the stems.

Another common native shrub is the spicebush, which has very fragrant, citrony leaves. 

Hickories are common as well. This is a photo of one leaf with five leaflets. 

I always feel some remorse while cutting native species back, but it has to be done if the trails are to remain clear.

Related post: Portrait of Sidewalk Neglect -- A post about plants that are growing over a neglected sidewalk.

Friday, June 03, 2022

Gently Enforcing the Gas Leafblower Ordinance

A couple days ago, I was doing some outdoor work when a landscape crew nearby revved up their gas-powered leafblowers. I put up with the din for about five minutes before finally heading over to tell them, in a nice way, that the town ordinance forbids the use of gas-powered leafblowers between May 16 and Sept. 30.

I got the crew's attention, then since they didn't speak english I explained in my broken spanish that "Hay una regla contra estas machinas hasta Octubre."

He nodded that he understood. I walked away only to hear them start back up a few minutes later. The situation was all the more frustrating because they were blowing leaves not off of a lawn but out of the woods, and because the leaves were soaking wet, it was going to take them forever to do what there was no rational reason to do in the first place. 

This time, I returned, didn't say a word, and photographed the machine and the address and the truck. He stopped again and got on his phone. 

I know the homeowners, and texted them about the situation. I could also have reported it to Access Princeton, but figured the problem was already solved.

You could hear that most wonderful silence as the birds continued to sing through the afternoon. My hat is off to the folks (Quiet Princeton?) who navigated the local political waters with a mixture of flattery and resolve to save us from these soul-sucking machines. (More info in the comment section about those who worked particularly hard to get the ordinance written and passed.)

Update, 6/15: Quiet Princeton informed me that a compliance officer has been hired by Princeton, so it is helpful to report violations to Access Princeton. Even if the non-compliance has been resolved at a particular residence, landscapers might try to continue using gas leafblowers elsewhere on their routes.

Happened to see a backpack electric leafblower at a nearby hardware store the other day. They at least exist.