Fig Buttercup Alert--Little Flower, Big Problem

Yes, spring can be lovely, with some cheery displays of daffodils, and magnolia trees in their glory. But it's also an all too good time of year to witness with dismay and alarm the ongoing and accelerating invasion of the Princeton area by fig buttercup. Also known as lesser celandine, it's a small spring ephemeral that seduces with its pretty flower, then takes over your yard and garden.

It has already radically changed the spring landscape over in the Pettoranello Gardens and Mountain Avenue area, and I've watched it spreading from yard to yard over the past five years in my neighborhood near Hamilton Ave and Harrison Street.

These photos are from Maple Street just down from Nassau Street, where a still localized infestation is radiating out from one of the yards. A yard will have one or two plants the first year, dozens the next, quickly multiplying to hundreds and thousands. It's pretty easy to see whose yard was first by the density and extent of the invasion.

Across the street, the fig buttercup is taking over the lawn and flower beds.

The next door neighbor has an invasion in its earlier stages.

Why be concerned? There are many degrees and styles of invasiveness. I'll compare fig buttercup with other aggressive plants below, but here are the essentials: Fig buttercup is an introduced species that has escaped any limiting factors that may have been present where it evolved. It's poisonous, so nothing eats it. The seeds and the abundant underground tubers allow it to spread rapidly. It can grow in the sun or shade, garden or nature preserve.

Some gardeners may feel relief that, like other spring ephemerals, it will fade back into the ground after a couple months. But that seems small consolation as it increasingly displaces other plants that might otherwise grow.

By comparison, myrtle is a groundcover that people plant and may later regret as it takes over flower beds. But it doesn't spread down the street to ultimately pave the local watershed. It merely vexes the gardener who planted it.

By the same token, wisteria vine poses a much smaller threat than porcelainberry. Though an abandoned wisteria vine can spread over an acre or more, weakening trees and suppressing all other growth, it doesn't spread by seed, so remains localized. Porcelainberry is a vine that not only smothers all other vegetation, including trees, but also spreads to new locales by seed.

Most pesky weeds of the lawn--wild garlic, dandelion, false strawberry, ground ivy, etc--have not become problems in nature preserves because they are either edible to wildlife or intolerant of shade.

That's what makes invasives like fig buttercup and stiltgrass stand out as major threats. They spread rapidly, tolerate shade and a variety of soils, and nothing eats them. Since fig buttercup dominates in spring, and stiltgrass dominates in summer and fall, they represent a one-two punch that dominates the landscape visually, and leaves little chance for other herbaceous species to prosper. Since both are not eaten, yards and preserves become increasingly inedible for wildlife.

Fig buttercup can be confused with winter aconite, which also blooms early with a similar flower, but the leaves are much different. Though nonnative, I've never seen winter aconite spread beyond the limits of a yard.

This photo shows the native marsh marigold in the foreground, with leaves much larger than fig buttercup's, which is in the background. (For a closeup comparison of the two species, click on this link.) The marsh marigold, by the way, is very rare. I've seen it only a couple times in the wild. I planted the one in the photo, over at Pettoranello Gardens, purchased from Pinelands Nursery many years ago.

Click here for past posts about fig buttercup (lesser celandine), including a letter I wrote to the Town Topics two years ago that struck a nerve.

What to do? If there are just a few plants, you can dig them up and put them in the trash (not the compost), being careful not to leave any small underground tubers behind. But though I've had organic sympathies all my life, and don't like to use herbicides, the easiest way is to use a squirt of 2% glyphosate on the leaves (Roundup is the most common brand, but more generic forms are available), or else some herbicide more specific to broadleaf plants. We take medicines, and when used responsibly in a targeted manner, herbicide can play a similar role in nature.

Environmentalism has been too caught up in good vs. bad, when the biggest threat to nature and ultimately ourselves, whether it be carbon dioxide or a pretty little flower, is too much of a good thing.

Composting Options: How to Build a "Wishing (the Earth) Well"

This post provides instructions for building a kind of home composter I designed. Called a "Wishing (the Earth) Well," it has a number of nice features, including being reasonably attractive while keeping animals from digging through your food scraps. Follow a few basics, and composting food scraps will be easy, odorless, and satisfying. Most any container on the kitchen counter will do, but we use a stainless steel bucket with lid. Every few days, there's a trip to the composter in the yard. Nature does the rest. 

With the suspension of the curbside collection of organics (food scraps and whatever other compostables would fit in the small rollcarts), about 800 Princeton residents who had discovered the satisfaction of keeping food scraps out of the trash are now wondering what to do.

One option for those with a yard is to compost at home. There are lots of composters out there. Those that you can rotate in order to mix the contents seem like a good idea, but I don't know anyone who has gotten them to work well. I've found that the ones that have direct connection to the ground are the most likely to succeed. Moisture, fungi, earthworms, and other decomposers all migrate upward to work their wonders on the composting material.

If you want to keep wild animals out of the compost (some areas of Princeton have rats), here's a design that keeps the food scraps contained in durable metal screening (hardware cloth), while using leaves to keep the foodscraps insulated from temperature extremes and hidden from view. It's called a Wishing (the Earth) Well because it looks like a wishing well but works in reverse, giving nutrients back to the earth rather than pulling water out. No turning or periodic remixing of contents is necessary.

When it's empty, it looks like this, with a circle 3 feet in diameter of green fencing, and a central cylinder of hardware cloth that holds the food scraps. The outer circle of fencing could be larger, e.g. 6' across, to hold more leaves, as long as the inner cylinder for food scraps is close enough to one side to reach.

When packed with leaves around the outside, it looks like this. The leaves insulate and obscure the inner cylinder of foodscraps.

More often, it looks like this, as the composting leaves and food settle. 

To get started, you'll need a roll of wire fencing, 3 feet high. See bottom of post for material details and purchase options.

For 3 foot circumference, measure out 10 feet of the 3 foot high fencing. (Note: Making the leaf corral larger, say, 6 feet across, works well, too. Adjust the length of fencing accordingly.) I use a long board to keep the roll of fencing stretched flat. Cut the stubs flush at each end so you don't have wire tips sticking out. Make a circle of the 10 foot length of fencing, overlap the ends a square or two, and use plastic zip ties to tie the ends together. Four should be sufficient. The corral portion is done.

Now for the inner cylinder where the food scraps go. You can see in the background some chicken wire, which is cheaper but not very strong, and not fine enough mesh to keep rodents out. In the foreground is a cylinder cut from a roll of hardware cloth three feet high and 3.5 feet long. I recommend cutting the ends flush so you don't have a bunch of the little metal stubs sticking out. 

Make the shape of the cylinder and have the ends overlap an inch or two, then secure with zip ties (5 or so)

The cylinder should work out to be about a foot in diameter, though you could make it bigger to increase capacity. If you have a particular top in mind, make the cylinder small enough in diameter that the lid will fit well and stay on top. Anything flat or bowl-shaped and sufficiently heavy to deter animals will be sufficient. I've used a piece of leftover bluestone, or an old metal bowl with a hole drilled in the bottom so it doesn't collect water, and weighted down with a brick.

For the bottom of the cylinder, cut a square of hardware cloth slightly larger than the circle and bend the corners down. Use a few plastic zip ties to keep it on. It will be pressing against the ground, so just a few zip ties should be sufficient.

The wire components should look like this when done, with whatever critter-proof top you want to use. (Note: In the photo, the top is an old aluminum bowl I happened to have around. It's slightly larger than the hardware cloth cylinder, so stays on top. I drilled a hole in the bottom of the bowl so water doesn't accumulate, and put a brick in it to discourage raccoons from lifting it off. Another top consists of a square piece of hardware cloth large enough to completely cover the top of the food scrap cylinder, upon which is placed a flat stone, e.g. a paver or small bluestone.)

All that's needed beyond this are 4-foot long stakes--one for the inner cylinder to keep it upright, and at least one for the outer ring.

A hubcap can be put on top, looking surprisingly classy, like a symbol of the sun. It can serve as the top if you don't have animals trying to get in, or can perch atop any other, heavier top you use.

Wire fencing, plastic coated or galvanized, runs $30-40 for 50 feet.

Here are some possibilities:
https://www.homedepot.com/p/Everbilt-3-ft-x-50-ft-14-Gauge-Welded-Wire-308301EB/205960855

https://www.homedepot.com/p/allFENZ-3-ft-x-50-ft-14-Gauge-Green-PVC-Coated-Welded-Wire-YG360502414G/305495538

The 3 foot high hardware cloth is also available in rolls.

The best prices for fencing and hardware cloth require buying more than you need. It's best, though, to have more than one Wishing (the Earth) Well, to provide more capacity in case the food scraps fill up the inner cylinder in the winter when not much composting and settling is going on. You can also prepare one for harvesting by letting its contents rot down into compost while adding the latest organics to the other composter.

Each fall, before accepting a new crop of autumn leaves, the Wishing (the earth) Well yields a wheel barrow full of rich compost, to be spread on the vegetable garden.

Though the leaf portion of the corral was topped off many times with additional leaves, all has decomposed down to what looks like 6 inches of leaves at the bottom. This outer crust of leaves disguises the rich compost underneath that is ready for use. The left tub shows the leaf mold; the right is decomposed kitchen scraps. The fall harvest of compost is ready to spread on the garden beds.

Here you can see that the rodents were not able to get into the foodscraps. Annual emptying is necessary so that tree roots don't have time to invade. 

Tip: The central cylinder can get heavy with compost. I used to lift it up, turn it upside down, and shake the compost out. A friend suggested just cutting the zip ties and empty the cylinder without flipping it over. 

Reassemble and fill with this year's leaves that in turn will be effortlessly composted by next fall. The leaves nicely disguise the inner cylinder of food scraps.



 It's so convenient to have leaf corrals discretely integrated into the landscaping here and there, so that leaves don't have to be hauled or blown long distances. In a house, we have discrete containers for trash in nearly every room. Why not have similar convenience in the yard?

Here's a closeup of the compost, soft and spongy, dark and rich. Ah, the rewards of all that non-labor and non-burning of fossil fuels.

One novel way to insure that all the leaves in the leaf corral are moist enough to decompose is to use one of those root feeder rods to poke holes in the pile so the rain can seep in. Better yet, connect a hose to the root feeder and use it to inject some water into the pile.

Leaf corrals can be easily hidden in a backyard corner, but if integrated into the front yard landscaping, they show neighbors and the community that leaves should be treated as a gift to our yards, and not something to be hauled away.

Some tips for using the Wishing (the Earth) Well:

• One thing to keep in mind is that animals such as raccoons may climb up the fencing to try to get to the inner column of food scraps. Though they don't succeed, they bend the wire fencing. More stakes would help, but stiff, springy wire woven around the top of the fencing is working well thus far. (Note: the wire I'm using is some leftover electric deer fencing wire a friend gave me.) Our composter in the front yard doesn't have this problem.
• As mentioned above, make sure the leaves are moist enough to decompose.
• Tree roots will invade from the bottom if the leaf corral is never emptied, which is fine, but if you want to use the compost elsewhere, remove the fencing some day in the fall, rake away the layer of leaves and shovel out the rich inner core of compost created over the summer. Put the fencing back in place and the corral is ready for a new fall harvest of leaves.
• The outer ring of leaves will keep reducing in size. This is good--it shows that the leaves are decomposing--but it also means the inner column of foodwaste will become exposed if one doesn't keep adding leaves or garden clippings to the outer ring. 

A white plastic pumpkin found on the curb during a dogwalk served as substitute for the hubcap.

A larger corral, six feet wide and called the OK Leaf Corral, yielded five big tubs of compost ready for incorporation into the garden beds.

The melon plant sprouted from the central cylinder of food scraps, which gets surrounded and hidden by leaves later in the fall, and was able to produce a small melon during those days when summer spends its last heat.

Work with nature, and nature will do most of the work. That's my wish, that more people would discover what a great partner nature can be.

One of the signs on the leaf corral says "Add a leaf and make a wish." I treasure the times I've happened to glance out the window and seen someone stop, read the sign, pick up a nearby leaf and drop it in, then walk off with a new sense of satisfaction. Maybe their wish was personal, or global, or maybe they just simply wished the earth well. We have taken so much from the earth. This leaf corral is a quiet way of saying it can feel really good to start giving back, in small and very large and steady ways.

Champion Brearley Oak in its Glory

There's a magnificent black oak growing, growing, growing in an unlikely place along Princeton Pike. Like the Mercer Oak, Jr. just up the road at the Princeton Battlefield, this oak too is of such distinction that it has its own corral. Driving by recently, I couldn't resist pulling over into the new Bristol-Myers Squibb parking lot and walking down to take a closer look at how it's doing. This champion tree--so-called because it's by far the largest in the state--is thriving, standing like royalty, master of its domain, with full access to sunlight all around and the soil all below.

The crown overflows its 100 foot diameter corral. Each of its millions of leaves is glossy and beautifully sculpted, the acorns small, as if this giant tree were compensating for the lone osage orange tree up the way about half a mile, barely a quarter of the black oak's height but with softball-sized fruits.

You can see the location of the Brearley Oak marked on this map, just above the hyphen in Bristol-Myers Squibb, close to Princeton Pike. The tree stands at the southernmost point in the Lawrenceville Hopewell Trail--a trail large enough to have its own nonprofit and website.

Nearby, to the east and north, is Brearley House and a park named after a great meadow from colonial and Indian times, and which the oak may have been witness to. That meadow was likely natural in part, but also managed at first by American Indians, who tended to burn the landscape, the better to attract game with the nutrient-rich growth that sprouted in the fire's aftermath.

There was a time when an oak this massive, with 20+ foot circumference, and perhaps 80 feet tall, would have been the rule, not the exception, when much of America was managed by American Indians, with the help of fire. The oaks have fire resistant bark and decay-resistant leaves adapted to remain on the ground as fuel. Then, when a low, mild fire started by lightning or people comes along, the leaves carry the fire across the ground, which in turn kills the oak's thin-barked competitors but not the oak.

The red dots on the map below, from Charles Mann's 1491, indicate areas managed by American Indians with fire. There are lots of dots shown in what is now NJ.

Red dots are areas managed by American Indians with fire (from the book, 1491)

In colonial and pre-colonial times, an oak like this would have had a rich understory of wildflowers and grasses, adapted to the ever shifting patterns of sun and shade.

One of the limbs is so long that it's  supported by a post.

And a lightning rod is attached on either side.

I'd love to go there sometime with a group of people. We'd recline on lawnchairs and gaze upward, tracing with our eyes the limbs' ascent towards the sky. A tree is like a city, with thoroughfares and sidestreets and cul de sacs of leaves. It is a solid built of air, some of which it breathed in before we were a nation.

Ignoring busy Princeton Pike and the sterile corporate lawns that surround it, this black oak soaks up the sun, drinks deeply from below, dreaming green dreams of mighty landscapes past.

A Turtle's Narrow Escape

If a truck passed over me while I was crossing the road, I'd probably pee in my shell, too. That's what it looks like happened here, having encountered the turtle on that small university road on the West Windsor side of Lake Carnegie, just after a truck had passed over it.

Just one more insult for a turtle to endure. It refused to tell me which side of the road it preferred to be on, so I put it on the canal side, where the habitat is, and hoped for the best.

Duck Takes Nature Walk at Herrontown Woods

Young ducks are great for taking on nature hikes, imprinted as they are on their human caretaker. We had one come hiking up the trail recently to the Veblen House grounds while we were working on preparation for this Sunday's Veblen birthday gathering (come if you can).

A writeup on the duck, a magpie, is at this link.

Non-Native Shrubs Shade Out Spring Wildflowers

This time of year, you can tell with one glance how many non-native shrubs are growing in a local woodland. Non-natives like privet, winged euonymus, and bush honeysuckle leaf out earlier than most native shrubs, reflective of their having evolved in a different climate from our own. Many of our woodlands are now thick with these non-native shrubs, and their early leafing out has ecological consequences. The spring ephemeral wildflowers have evolved to utilize the sunlight available during that window of time in spring when the woody plants above them are still dormant. Introduce woody plants that leaf out earlier, and the wildflowers can't store up enough energy to bloom the next year.

This problem will be exacerbated as we lose the many ash trees in our woodlands, since the nonnative shrubs will likely grow all the more densely as more sunlight reaches the understory in summertime. At Herrontown Woods, we're cutting down the non-native invasive shrubs, to allow more sunlight to reach spring wildflowers, and also to allow native shrubs a chance to thrive.

A Pretty (scary?) Snake in the Basement

Earlier this week, I received the photo below in an email entitled "Copperhead?". The email was from Robert Socolow, a distinguished physicist at Princeton University. He usually focuses on climate science, but this past weekend his focus was drawn to an unusual snake he found in his basement up on the Princeton Ridge. This particular snake subsequently met its demise, but the thought that it could be a venomous copperhead snake made him leery of spending any more quality time in his basement.

My first guess was a corn snake, but we needed more than a guess. I sent the photo to my friend Perry in Durham, NC, where I used to see copperheads now and then in my old stomping grounds along Ellerbe Creek, their heads above water, gazing upstream.  He in turn sent it to his friend and Duke University biologist, Ron Grunwald.

The answer came quickly: Eastern milk snake, nonvenomous. They're said to be fairly common. According to the wikipedia page, they are a kind of king snake that can be found in various habitats, including rocky slopes (the Princeton Ridge), and also in barns. Their presence in barns may be the reason a myth arose that they suck milk from cows, which anyone who knows snakes and cows will agree is udderly ridiculous.

Rob was relieved, but the episode begged the question: Are there venomous snakes in New Jersey? The answer to that came very fast, when up popped the website for Conserve Wildlife Federation of NJ, and a post on the northern copperhead (affectionately known among herpetologists as Agkistrodon contortrix mokasen). For anyone thinking of copperheads as a southern species, it's a surprise to learn that the northern copperhead's range actually begins north of Princeton, extending from the Sourlands up through northern NJ.

The range of the one other venomous snake in New Jersey, the timber rattlesnake, conveniently avoids Princeton, with populations both north and south. The scientific name for this snake is Crotalus horridus horridus, which seems unscientifically judgemental. 

For the curious, there's a nice-looking pamphlet of New Jersey snakes at this link. 

Thanks to Rob for sending the photo, and to Ron for the identification. Though the snake may well have been doing a fine job limiting the number of mice and camel crickets in his basement, Rob was understandably prompted nonetheless to reaffix the screen that had fallen off a drain pipe leading from his basement to the great outdoors.

A Deer's Landscape Services

Funny. I didn't remember requesting landscape services. Deer hadn't shown up in our backyard since around 2005, when the birth control experiment was still underway and the females were looking elegant and very Princetonian with those identification cards hanging from their ears. Maybe it was taking refuge from hunters, or had had enough of rutting season.

Deer are expert landscapers, trained from birth in the art of pruning. They wouldn't think of driving around town in those giant fossil fuel-consuming trucks that deploy gangs of mowers to quash nature's vertical ambitions.

Deer are too considerate to make a racket with leaf blowers. And instead of releasing a cloud of fumes to sting your nose, they leave behind discrete contributions of fertilizer. They do the landscaping for free, but have a strong independent streak, refusing to adjust their methods to an owner's wishes.

Deer are very sensitive. Even though I stood ten feet back from my bay window, I still had to freeze several times so as not to spook my subject. It's impressive how they are so observant and "in the moment"--a state of mind we too might more easily attain if we were further down the food chain.

When I stepped outside to shoo it away, it didn't flee back over the fence but instead ducked behind some shrubbery in a back corner, waiting for my next move.

Once it realized I was not a threat, but instead just another among Princeton's backyard paparazzi, it regarded me with what appeared to be disdain.

No longer feared, I went back inside without finding out from where it came into the yard.

It was interesting, though, to watch it at work, browsing maybe ten leaves of our oak-leafed hydrangia before moving on to munch some grass. Though I've heard stories of deer wiping out a gardener's favorite plants overnight, my experience is that animals generally lack a thoroughness, whether it be browsers or predators.

My theory with deer is that their alertness to the potential for attack makes a patient devouring of one shrub less adaptive than a few nibbles here and there. And if much of what they eat has some level of toxicity, browsing can help reduce the risk of consuming too much of any particular toxin at any one time. Light browsing also promotes quick recover by the plants, as long as there aren't too many deer visiting the same plant. This suggests that deer could actually be good stewards, if their population was in balance with the landscape.