Saturday, April 13, 2019

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.




Wednesday, April 10, 2019

Ducks Visit the Backyard


A pair of mallards visited our backyard this morning. The male stood in the middle of the lawn while the female strolled down the garden path, presumably in search of a nice pond to call their own. Were they checking out nesting options? If so, I can't imagine they were pleased. The only standing water is the fillable-spillable tub that catches water from the downspout.

The most appealing interpretation of their surprise visit is that one of them might have been born here five years ago, back when by chance we had ended up with a pair of mallards among our fine feathered pets in the backyard. Being a male and female, they soon had five ducklings to call their own. As the ducklings grew, the yard seemed to shrink, overfilled as it now was with ducks and chickens. There were times when we'd hear the nasal call of geese flying overhead, or one or another duck would fly in an impressive arc around the boundaries of the yard, and I'd think for sure they would respond to the call of the wild and venture off into the big world beyond our fenceline. But they never did.

The mallard family eventually ended up at a farm outside of town, whose owners were kind enough to take them off our hands. I read that mallards live 5-10 years in the wild. How lovely to think that they might have come back to have a look around at their old haunts.

For some posts about the ducks we had behind our house on busy Harrison Street, type the word "mallard" into the search box for this blog, or follow this link.

Monday, April 08, 2019

Maintaining a Towpath, and a Meadow


Visiting the towpath for the first time in a long time last week, I found a fresh layer of crushed stone being laid down. May this renovation live long and prosper, for we found out back in August of 2011 what massive storms can do to a wonderful facility like the towpath. That devastation lingered for many months, for lack of any funds to repair the damage. Now, apparently, there's been an infusion of funding, at least for the towpath and hopefully for the NJ parks department itself.


Most people go to the towpath to get some exercise and fresh air next to the water. I go to check on a little nature trail loop we created just upstream of the Harrison Street bridge. The first post on this blog, back in 2006, documents that first year's "harvest" of wildflowers after the state parks department reduced the amount of mowing it was doing in the meadow between the towpath and Carnegie Lake.

Thirteen years later, I'm still serving as steward of that meadow, marking elderberry shrubs so that the parks crew will avoid them during the annual early spring mowing of the meadow. Otherwise, the elderberries would have to resprout from their roots each year and never get a chance to bloom.


Along with the native wildflowers that bloom there in mid-summer, there are remnants of non-native ornamentals, like this row of forsythia, left over from when the towpath was planted by the university to ornament the entryway into campus.

Spring is also a good time to inventory what else needs to be done when the parks crew comes to mow. Maintenance, seldom given its due, makes all the difference, whether it be a trail, a meadow or a planet.

Thursday, April 04, 2019

Nature Walk Saturday, Daffodil Planting Sunday at Herrontown Woods


NATURE WALK--SATURDAY, APRIL 6, from 9-11am

Frog eggs in vernal pools, the distant hammerings of pileated woodpeckers, spicebush in flower--these are some of the sights and sounds we'll likely encounter on a nature walk at Herrontown Woods this Saturday, April 6, from 9-11am. The walk will be co-led by Mark Manning and Steve Hiltner. Mark is a highschool teacher in Hopewell who has been walking through Herrontown Woods with his son and documenting the species of frogs and salamanders present. He encourages anyone interested in birds to bring binoculars. Steve is president of Friends of Herrontown Woods and can speak to the plant life and history of the preserve. The walk will end at the Veblen House, with some light refreshments. We'll take one of the drier routes through the preserve, but be prepared in case some portions of trails are wet.

Meet at the main parking lot for Herrontown Woods, across the street and down the hill from the main entrance to Smoyer Park. Maps at this link.


VEBLEN GROUNDS CLEANUP AND DAFFODIL PLANTING -- SUNDAY, APRIL 7, 2pm


In honor of Elizabeth Veblen, we are recreating the fields of daffodils that graced her Veblen House garden. The photos are from the 1950s.

Bring a bulb planter or shovel if you have them, and good gardening clothes/gloves. We'll also do some general cleanup of the grounds. We'll have a few tools and gloves and a little something to drink and eat.

Meet at the Veblen House, down the gravel driveway at 474 Herrontown Road. (Entrance across the street from 443 Herrontown Rd)


Here's another photo from the 1950s, with Elizabeth Veblen walking the grounds of the cottage. Not surprisingly, the distinctive boulder in the foreground is still there, making this photo very useful for helping recreate the landscape the Veblens enjoyed before they donated their homes and land to the public.

The Green Slime That Ate My Ponds

Not quite in the spring spirit, I was going to write about lawn blotch, but that subject was covered five years ago. Better to launch into something new and (uncomfortably) fresh--


namely, the green slime that has crept across my backyard miniponds over the past six months or so. Gone are the depths of clear water I once pondered. The visual is disturbing, recalling as it does


the images of coral reefs whose brilliant diversity has succumbed to overheating, with algae draping itself over the skeletal remains.

All the more distressing to find algae coating water in a well,

and coloring an ephemeral stream down the slope from the Veblen House.

Is this a new algae, accidentally introduced and proving invasive? Or is there something about the unusually wet weather New Jersey has been having? If this stuff covers over vernal pools, the frogs and salamanders will surely be in trouble.

It would be nice to think that this is merely a temporary aberration that will clear up and not return any time soon. A nutrient imbalance, perhaps.  One source describes how phosphorous can be released from the bottom of a pond if the water runs out of oxygen.

As scientists are wont to say, more research is needed, and please leave a comment or send an email if you've been similarly surprised this spring by similar smotherings.