Mile-a-Minute Vine in Princeton

Each year I conduct a solo campaign to keep the highly invasive weed Mile-a-Minute out of Princeton. It's a prickly annual vine that grows each year from berries produced the year before. Knock it out before it produces berries, and eventually there will be no berries to sprout. Otherwise, the infestation will grow and birds will spread the berries across all of Princeton, to spring up in backyards and vex homeowners with its thorns and rampant growth.

I know of two infestations--one at the Princeton Battlefield, the other down off West Drive on the gravel road to Rogers Refuge. Yesterday, passing by Princeton Battlefield, I stopped to uproot what Mile-a-Minute I could find and leave it on the lawn to dry in the sun. Like most annual plants, it has whimpy roots and can easily be pulled, wearing a good pair of gloves.

Princeton Battlefield has a remarkable history, which makes it all the more remarkable how ahistoric the landscaping is. Non-native turf is surrounded by giant kudzu-like topiaries of non-native porcelainberry vine growing over the native dogwoods that were proudly planted for the 1976 bicentennial. There's little hint of what the Clark Farm looked like on that fateful day in January of 1777. The lack of botanical context doesn't fit with the people and era the Battlefield is meant to celebrate. Plants were important to George Washington and other leaders of his time. They were farmers. It's not coincidence that the United States Botanic Garden was built to stand next to the U.S. Capitol building. What grew upon the land mattered back then. They didn't mow the lawn and think their work done.

Seeing a landscape so invaded and out of balance, I sometimes imagine a hospital with no doctors or nurses, only custodians dedicated to keeping the place clean. The patients are on their own, unless a volunteer doctor happens by to treat some localized infection. That's the situation in the vast majority of our landscapes, cared for by custodians armed with raucous mowers and leaf blowers, oblivious to the complexities of nature and its needs. 

In the meantime, I pull the Mile-a-Minute, trim back some small portion of the porcelainberry vines so the dogwoods might live another year, and wonder at the world's disconnect with nature.

The two photos show 1) porcelainberry vines overwhelming a dogwood tree, and 2) another sea of porcelainberry in which only the similarly invasive Canada thistle can manage to lift its pink flowers above the swarm.

The Grass That Ate The King's Highway

There's a curious sight as you approach Montgomery from Princeton on Route 206. Something is eating the Kings Highway. 

That something is Phragmitis, most frequently encountered in its highly aggressive, non-indigenous form. In wetlands, it displaces even the tough native cattails. On the other side of town, in Rogers Refuge just below the Institute Woods, we've been working for years to keep it from taking over the marsh.

Spreading its tall tassels along freeway ditches, it dominates the New Jersey meadowlands and can be considered a worldwide weed. Its scientific name is as sprawling as its growth habit: Phragmites australis subsp. australis. The native version, less aggressive and now hard to find, is termed subspecies americanus.

One source describes the introduced variety as "a hardy species that can survive and proliferate in a wide range of environmental conditions." Sometimes it's planted intentionally, to treat wastewater or reduce soil erosion. Mostly, it plants itself, then expands relentlessly, oblivious even to normally intimidating barriers, like asphalt.

The common reed is a grass, like bamboo is a grass. Unlike bamboo, which lives for decades without flowering, Phragmitis blooms each year, combining abundant seed production with bamboo's powerful capacity to spread underground. That combination makes it a transformative force not only in nature but in human habitats as well. 

Redbud Leaffolders and Orchids--Herrontown Woods in July

While the woods seems to slumber, July brings another wave of flowers at the Herrontown Woods botanical garden and the Veblen House grounds. Whether the number of flowers constitutes a wave or a ripple, the photography that is standing in lieu of an actual nature walk during COVID times captures something of the feel of walking the pathways.

I have seldom seen Culvers Root growing in the wild, but it is a native with a beautiful form to its flowers. You can see the flowers beginning to open at the bottom of a spike, commencing a slow progression upward that serves the pollinators well.

The mountain mint donated to us is thriving, its strong minty flavor protecting it from the deer.

Shrubby St. Johns Wort blooms for a long stretch in the summer, living up to its latin name, Hypericum prolificum. The deer leave it alone as well.

We human deer are letting a few pokeweeds grow to maturity. It has an annual stem growing from a perennial root, and can become too numerous if left unchecked. A previous post mentions the intentional or unintentional use of its berries as a dye, and an interesting tree-like relative it has down in Argentina, called the ombu.

Not sure what this soporific bumble bee was doing on a velvety leaf of wooly mullein, a dramatic nonnative weed I associate with rail lines in the midwest, but which shows up here and there in Princeton.

The drought prompted the installation of a gutter and cistern next to the roof of the kiosk at the Herrontown Woods parking lot. One rain keeps us in water for weeks, as we walk around the gardens, giving new plantings a much needed drink.

Insects have been taking advantage of the many kinds of native plants we're growing--more than 100 species thus far. Meadow rue, for instance, is a seldom encountered wildflower in Princeton, discouraged by shade and the appetites of deer. But in the botanical garden, we can grow it in a protected, sunny setting. On May 10th this year, one of the tall meadow rues was found "donating" its foliage to caterpillars of the Meadow Rue Owlet moth, Calyptra canadensis. Thus a protected setting for seldom seen plants provides habitat for specialized insect species that otherwise have slim pickings in Princeton.

Another giving was discovered a couple days ago, on a redbud tree, some of whose leaves were folded up and turning brown.

Strands of silk tether the leaves, making protective chambers within the wrappings.

Opening one up, like a clamshell, reveals some energetic caterpillars busy chowing down and leaving dark trails of frass in their wake.

The speedy caterpillars are larvae of the leaf folder moth, with the provocative latin name Fascista cercerisella. Readers will be relieved to know that the insect is not a fascist. Originally, the word meant "bundle", as in a bundle of sticks, which can be extended to bundles of people who are part of a political movement. A fascicle means a bundle of leaves or flowers, while the Fascista caterpillar bundles itself up in a folded over leaf. The "cerce" in cercerisella likely comes from the insect's preference for laying its eggs on redbud trees, Cercis canadensis.

Up the trail at Veblen House, a patch of wineberries is going uneaten. As we've been clearing the invasive growth on the Veblen House grounds, a neighbor lamented that we had removed her favorite patch of wineberries, whose fruit are one of the small rewards for those who persevere through the muggy heat of a Princeton summer. Responding to neighborhood input, we've kept a few patches of wineberries.

Few will notice that the green fringed orchids at Veblen House are in full bloom. We've caged some to protect them from the deer. Below is an enchanting closeup of the flowers, giving the impression of wood sprites.

Princeton's Fuel Tank Raingarden Wannabe

Why would a plant lover be drawn to this desolate scene of concrete and asphalt? Because there's a raingarden behind that fence, or at least a raingarden wannabe, and that means I'm seeing not what is, which is pretty drab, but what could be, which is a dynamic, jubilant planting of native wildflowers, grasses and shrubs filling that skinny raingarden squeezed between the sidewalk and the town's fuel tank. The fuel tank was for awhile serving double duty, fueling town vehicles while its appearance fueled controversy in the neighborhood. A fine rain garden planting could go a long way towards healing the discontent, in my humble, totally plant-biased opinion.

The first good news is that the fresh layer of asphalt there appears to be appropriately tilted to shed its runoff towards the raingarden. What is a raingarden, after all, if the rain that falls on the surrounding topography doesn't flow towards it?

For some reason the raingarden hasn't been planted yet, so the plants have gone ahead and started planting themselves. It's looking a little sparse thus far. Or you could say that the plants are social distancing.

Whenever I see plants trying to colonize bare dirt, I think of people who live in an emotionally impoverished situation. Back when I was in that predicament, I was drawn to places like this. Weeds trying to grow in parched ground were my friends and fellow travelers. Maybe that's why I can remember plant names when most people struggle, because the plants aren't just variations on green. They touch something deeper in me.

This late-flowering thoroughwort is a keeper--a native wildflower whose name is unlikely to flow smoothly from many tongues. It grows like a weed, and often in weedy places, like abandoned fields or roadsides, but can sometimes achieve great elegance of form when it becomes covered with plates of white flowers in late summer. It shows up early, but blooms late. Thus the name.

Here are the leaves of mugwort, which adds no color and spreads aggressively underground, taking over neglected raingardens over time. It's a force for monoculture and monotony that must be countered early and often.

Smaller scale weeds are clustered here, close to the ground, with dandelion on the lower right, a mock strawberry in the middle, and one 3-seeded mercury on the left. When I see one or two mock strawberries like this, I'm also seeing five years hence when it will have spread to coat the ground in an unattractive and inedible way. That increases the motivation to be proactive and pull it out now, before the task becomes overwhelming. This ability to imagine the future, learned in a garden, is directly translatable to global issues like climate change, where the job only becomes harder the longer one waits. 

Lots of homeowners puzzle over what to do with hundreds of oak seedlings in their yards, when everyone is telling them we need to plant more trees. Most tree species don't need help. They plant themselves, often in inconvenient places, like this raingarden.

Playing the editor, I'd say this nonnative red clover is a keeper as well, but pull the tall sweet clover at the other end of the raingarden. Sweet clover can be kind of pretty in a gangly way, but it is one of those midwestern and western weeds that appear to be expanding eastward, like teasel, Queen Anne's Lace, knapweed, and wooly mullein. Having lived in the midwest, I've seen how they can start to take over.

Leaping into the void in plants and action a couple months ago, I pushed some "live stakes" of buttonbush into the bottom of the raingarden. Despite the poor, hardened soil, they have sprouted. Here again, I'm seeing not so much the less than impressive seedling but instead the 8 foot high shrub it could become if it's allowed to get well established.

Just up Witherspoon Street, at the Princeton Recreation Dept. headquarters next to the community pool, is a demonstration of how gardens can look if there's someone knowledgeable taking care of them year after year. There's some serious tending going on here. Even the scarily aggressive variegated goutweed (whitish leaves on the left), which tends to take over gardens, is neatly contained in a discreet clump. These gardens owe their existence and beauty

to Vikki, whose job description in the Recreation Department probably has nothing to do with plants. From what I've seen over the years, it's clear that Vikki is one of the few people in town who is hard-wired to have a soft spot for public gardening, like Polly Burlingham with her hanging baskets downtown, and the various school gardeners, and like Dorothy Mullen was until she left our world earlier this year. I'd say that all it takes is love, and from that all things follow--vision, knowledge, persistence, strategic timing.

Maybe the sad, forsaken raingarden wannabe just a block away will somehow become loved ground. It's got "good bones"--sun, inputs of moisture. Good things could happen.

Proliferating Paradise

If you asked me what a utopian landscape might look like, it would be something like this. People talk more of dystopia than utopia these days, but this enclave stirred memories of utopian dreamers who were more common a half century ago. This is not a utopia filled with fantastical gizmology, but a more basic collecting of solar energy by plants and people to fill our needs for comfort, food and beauty. Though a deep forest would be somewhere nearby, houses would be producers, not just consumers, their roofs shaded by solar panels sending renewable electrons out into the neighborhood grid. And their front yards would be producers as well, of a joyous mix of wildflowers and vegetables.

Wild plants would mingle with domestic, and people would be a gentle mix of wild and domesticated natures as well. On this particular day, a neighbor was harvesting cucumbers and tomatoes while we plant lovers were inspecting the leaves of a curious plant grown from seeds we had collected from a wild remnant on the outskirts of town. We continue to be stumped. It's some sort of Silphium, not quite cup plant, not quite rosinweed. Genius nature has taken our breath and turned its carbon into yet another surprise.

The garden is largely the work of my friend Perry in Durham, NC, who began gardening in his own yard, then extended his work into his grateful neighbor's. Other neighbors on the block have picked up on the theme, getting acquainted with plants one at a time, until their lawns too have been displaced by something much more interesting and productive. It's a miniature experiment in proliferating paradise.

Perhaps paradise is too strong a word, being associated more with leisure than production, more with a tropical beach and soft sea breezes than an urban front yard. This is a plant-based, pandemic-borne, home-centered paradise.

I'm in Durham partly to see a close friend, but also to work on my house there, a 1919 house surrounded by towering oaks, but with a big lawn drenched with sunlight and potential to grow all kinds of interesting things. Being a long-distance gardener is even more challenging than being a long-distance landlord, particularly during a pandemic, but last fall, we started by planting seeds of local wildflowers and grasses around stakes in a part of the lawn where the soil had been freed of Bermuda grass. Perry didn't get my hopes up, sending periodic reports this spring of copious amounts of chickweed and weedy cranesbill filling the void in the lawn. It was a great surprise then to finally show up and find an enthusiastic crowd of intended plants around each stake, enough to populate a much larger portion of the lawn.

This is an unorthodox way of proliferating prairie. I used a similar technique at the botanical garden at Herrontown Woods in Princeton, where toddlers and their moms planted wildflowers in staked pods like this--mini-nurseries of clustered plants that were transplanted the next year to begin filling the whole forest opening. As the transplants produce seeds, they expand the overall planting still further.

Perry's been using incrementalism in a Durham nature preserve as well. At 17 Acre Wood, the first urban preserve I helped create in Durham 20 years ago, Perry and I checked out the hazelnut crop in a floodplain he has been working to shift towards native species.

One of the toughest spots was clogged with climbing euonymus, english ivy and periwinkle. Trees tend to be native, the understory not, but Perry is shifting the balance. It's hard to grow much in deep shade where water stands for much of the winter, but where the invasives have been removed, elderberry and jewelweed have bounced back, and a patch of lizard's tail has appeared.

The work is partly ecological, partly aesthetic, partly public safety, since removing invasive shrubs and vines improves vistas and sightlines along a public trail. This West Ellerbe Creek Trail, which follows the creek through the preserve, is also a story of incrementalism. It was a big hit with neighbors when it was built by the city in 2001, but would not have been built at all if not for the small steps that preceded it. A county government grant had helped our nonprofit create a nature preserve along the creek. Then the city, seeing we had created a destination, built the creekside bikepath to reach it. The result was a way for neighbors to take a nature walk in their own urban neighborhood.

To shift the world towards paradise, we really don't need new ideas, only people and organizations and governments doing what they each do best, combining incremental action with caring about the world and what we'll pass to future generations.

Cardboard Quells the Chaos--Renovating a Garden Bed

When plants aren't "playing well with others," sometimes one has to lay down the law. That's what happened in an area of the garden that got away from us. While we were off living our lives, Lizard's Tail, sunflower, and a common goldenrod were quietly sending their rhizomes out in all directions. Ground ivy and mock strawberry were overwhelmingly undertaking relentless stoloniferous expansions. And the once endearing, highly edible blue violets were pushing their way into every nook and cranny.

Some nature writers congratulate themselves on their tolerance for all living things, but that tolerant pose somehow doesn't extend to species that threaten people, e.g. COVID-19. A lot of the love gardeners feel for the plant world is expressed, ironically, by killing some plants that are threatening others. I may love red oaks, and can see that even poison ivy has an ecological role, but that doesn't mean I'm going to let a thousand seedlings take over a garden bed.

In extreme cases, where the desired and undesired become hopelessly entwined, or a garden path disappears in a sea of "way-too-much-of-a-good-thing" overgrowth, it's time to bring in the cardboard.

Yes, cardboard. Given all the negative forces in the world, cardboard stands out as a beneficent presence, rivaling that of chickens, or perhaps peanut butter, outstanding in its inborn capacity to do good with very little downside. Occupying a niche somewhere between wood and paper, cardboard can take myriad shapes to serve myriad purposes, whether keeping stuff together in a basement or rising into high art at a museum or on a stage.

In a garden, cardboard serves in a sprawled state, depriving weeds of sunlight, and creating a barrier that's strong and lasting enough that weeds can't push through. Some people use landscape fabric, but over time soil begins accumulating over the fabric, weeds grow on top, and the buried fabric then becomes a nuisance that needs to be pulled out and thrown away. Cardboard serves as a barrier for a season or two as it slowly decomposes, leaving no trace.

Here's the legacy of neglect, with path stones retrieved from the chaos,

and a tangle of way too aggressive sunflowers and violets. All are beautiful in their way, but hard to keep in balance with everything else.

Before laying down the cardboard, a few beebalms and lizards tail were retrieved from the mess with the intention of planting them elsewhere.

A variety of sizes of cardboard are useful. I put a few desired plants in--the sort that don't spread but instead grow in bunches--like ironweed, boneset, hibiscus, culver's root, tall meadow rue, cutleaf coneflower--then surround them with overlapping pieces of cardboard. More plants can be put in along the seams or by punching a hole in the cardboard. The walkway stones were put back in place, and other stones used to keep the cardboard in place until we can cover it with mulch.

Here, for instance, we're using cardboard as a base for a walkway around the "Veblen Circle" of native plants at the botanical garden next to the Herrontown Woods parking lot. A stone border is laid along one edge of the cardboard, and chips are placed on top, completely disguising the cardboard. The result is a weed-free path for a year or two. That's a whole lot easier than pulling each individual weed.

Towpath Nature Trail Loop in Late Spring

It's good to see a nature path well used and free of obstructions, which is the current state of the nature loop that winds through a wide section of the DR Canal State Park, just up the towpath from Harrison Street. (for posts showing the trail in different seasons, type the keyword "loop" into the searchbox for this blog) The whole area was being mowed until I convinced the state park folks to let the wildflowers grow, back in 2006. They then created a nature trail loop through the open woodland landscape between the canal and Carnegie Lake, and maintained it beautifully until a couple years ago, when they asked Princeton University to take over the mowing of the trail. PU actually owns the land, even though it's part of the state park, and they finally agreed to maintain the trail. I was out there with a chainsaw, doing what I could during the transition, given the tendency of trees to fall across the path.

As of June 2, the path was looking great, possibly due to university care, but thus far maintained more by foot traffic than anything else. Here's a plant-person's take on the interplay of native and non-native species to be found along the way.

Common milkweed is one of the few natives that can compete with the highly invasive mugwort. Both spread underground.

Bittersweet nightshade blooming on the shore of Lake Carnegie.

Blackberry flowers, with the green beginnings of the berry emerging as the petals fall.

Here, for comparison, is multflora rose, a nonnative shrub, more common than blackberry, with larger clusters of flowers, curved thorns, and lacking the linear grooves on the blackberry's stem.

Orchard grass blooming. Non-native but not very aggressive, often found as a single, erect clump here and there.

The orange-tinted remains of last year's broomsedge, which is not a sedge but instead a native grass, here lining the trail. Like other native prairie grasses, broomsedge is adapted for periodic fire, which its persistent stems encourage. A field of broomsedge can be very pretty after it turns color in the fall, though farmers associate it with poor soil.

Learn to recognize poison ivy in all its forms. It often looks glossier than other plants with three leaflets, reddish when young, with traces of red remaining in the stem later on. The pair of lower leaflets often show a "thumb" along the lower edge, a subtle version of which can be seen here in the mature leaf. People are surprised to learn that vines like poison ivy only bloom when they find a tree to climb up.

This is a hopeful sight for any lover of Joe-Pye-Weed, which will ornament the trail later in the summer in the patchwork of shade and sun beneath the scattered trees.

One of the dogbanes, which like milkweed will exude milky sap when you pluck a leaf.

Look closely at the photo below of Viburnum shrubs, and you'll see that the leaves of the one on the left are more distinctly toothed. That's the native arrowwood Viburnum (V. dentatum), while the shrub on the right is linden viburnum (V. dilatatum), a nonnative that has become surprisingly invasive in local preserves. As often happens, the native is seldom encountered, while the non-native is common, most likely due to deer preferring to eat natives.

If you know your plants, then you'll look at this small clump of leaves and feel happiness at all the yellow, cone-shaped flowers cutleaf coneflowers will produce later in the summer.

And even happier when you find a large congregation of cutleaf coneflower rising like a very slow-motion firework that will explode in color a month from now.

But knowing plants also allows you to foresee less auspicious trends, as the porcelainberry (NJ's kudzu wannabe) begins to grow up and over most everything in a smothering embrace. Persistent emails have yet to convince the university of the need to mow the field once a year in late winter, like state parks used to do. Annual mowing is the key to sustaining this open woodland of scattered trees lording over a vista of wildflowers.

There's a little parking just across the Harrison Street bridge. The trail loop is on the Princeton side of the towpath, just in from Harrison, with what looks like a birdhouse at the trailhead. Returning via the canal, I happened to see this yellow iris (I. pseudacorus), framed in the trees' reflection in the canal. The native iris sometimes seen is blue.