Egyptian Walking Onion

Here's a fun and edible plant. We called them Egyptian onions back in the 70s, and I acquired one for our Princeton garden a few years ago. It's a perennial that grows like a scallion in the spring, then starts forming something interesting on top.

They grow new plants at their tips, sending out new leaves like slow-motion fireworks.

You can see the bulbs of new plants at the tip.

The weight of the new plants causes the main stem to bend over until the new plants touch the ground and take root. Thus, the term, "walking onion". The plant has its own website where you can scroll down to get more details about growing and eating.

Other plants use this strategy, including a sedge called green bulrush (Scirpus atrovirens), a much less edible plant that grows in wetlands around Princeton and sprouts new plantlets at the tip of its leaves in midsummer.

Lonely PawPaw Seeks Cross-Pollination

Round about Mother's Day, my friend Karla received this email: "Lonely apple tree seeks similar for discreet short-term relationship. Afternoons preferred." Just in case there was any misunderstanding, some explanatory text was added: "My tree is blooming, for the first time; is yours? If so, can our trees make a date? Warm regards."

As it happened, her husband Steven was headed that very day to South Brunswick on a related mission, in search of pollen to satisfy the fruiting needs of another kind of fruit tree, the solitary pawpaw planted in their backyard some years ago that was now in full bloom. Though it had sprouted an additional trunk, it was still lonely, genetically speaking, and unlikely to set fruit unless visited by pollen from another pawpaw patch.

Thrust into the role of pollinator, Steven found himself at a distinct disadvantage. He had neither the wings to search the greater Princeton area for other pawpaw trees, nor sufficient olfactory apparatus to detect the subtle carrion-like odor pawpaw flowers use to attract pollinating flies. And since Google Maps does not (yet) provide directions to New Jersey's pawpaw patches, the search for prospective pawpaw mates required considerable research savvy. Even upon arrival at the best prospect he could find, the orchards at Rutgers, he still required the kindness of strangers to find the pawpaws amongst all the other fruit trees in the no-doubt vast plantings at Cook College.

This sort of matchmaking is becoming more common as the local food movement, perhaps abetted by backyards made sunnier by tree-toppling storms in recent years, prompts the planting of solitary fruit trees in cloistered backyards--peaches, apples, cherries, figs, persimmons, pears, and the occasional pawpaw--all with uncertain prospects for leading a healthy, promiscuous life of cross-pollination.

For those who know pawpaws only from the childhood lyric about a "pawpaw patch", they happen to be a native understory tree in the Annonaceae--a family of mostly tropical species. One relative of pawpaw grown by the Incas is touted as perhaps "the greatest fruit on the planet", with a taste combining mango and banana. Pawpaw, adapted to the north, offers a chance to grow tropical tastes in cold climes. Though delicious, its shelflife is short, which has thus far limited the pawpaw's commercial potential.

Thanks to the internet, I now know that the "way down yonder in the pawpaw patch" phrase that I've been carrying around in memory all these years comes from a boyscout song. I did not personally reach the status of boyscout, having earned my bobcat, wolf and bear badges in cubscouts only to lose momentum during a leadership void in that critical transition from cub to boyscout. The transition is called webelos, which stands for "we'll be loyal" scouts, a molting process that not everyone successfully completes.

If I had, I might have learned the complete lyrics for Pawpaw Patch, and known that "way down yonder in the pawpaw patch" answers the musical question "Where oh where oh where is Susie?" It matters where Susie is because she happens to be the "queen of Hawaii", which goes with the pawpaw's tropical family roots. If you ever go to Hawaii, you may encounter some of pawpaw's relatives, like the ylang ylang, soursop, and sugar apple. However, according to the song, you needn't go way down to Hawaii, because Susie will teach you to hulu way down yonder in the nearest pawpaw patch. If not completely distracted by Susie's hulu tutorials, the astute boyscout will note that "way down" and "patch" are descriptively correct, because the pawpaw tends to grow in rich bottomlands, and forms clones from its spreading roots.

There's another lingering pawpaw-related mystery knocking around in my memories. In my parents' Michigan backyard in the pre-internet 70s, a pawpaw sprang up spontaneously one year, grew into a patchlet of several stems, and after a few years began bearing flowers and a few fruit the size of a small mango. Where the pawpaw came from is a mystery, as was its capacity to bear fruit, because there was no known patch nearby, and the seeds looked much too large to navigate a bird's digestive tract. We didn't ask questions, however, because they were delicious. A bit of pollination assist with a cue tip may have helped with yield one year, which the raccoons and squirrels were grateful for.

Steven's recent research, empowered by the internet era, has delved far more deeply into the sexuality of a pawpaw. Way up yonder in this pawpaw post is a picture that Steven sent me of two pawpaw flowers, the green one not yet having acquired that lovely burgundy hue that flies are supposed to mistake for dead meat.

If a pawpaw flower were able to speak to its sexuality, it would say something like "I was female before I was male." Here to the left is a male flower, which is really a female flower a few days later. Looking closely, you can see a subtle difference. There are now yellow (male) anthers surrounding the green dot in the center (female stigma). The logic is that the anthers on any particular flower open up as the stigma is closing down, thereby preventing a flower from pollinating itself.

But that logic suggests that a tree with flowers in different phases could in fact pollinate itself, with pollen from one flower spreading to the next, and make fruit without importing pollen from elsewhere.

Still, the available information suggests that it helps to have cross pollination from one pawpaw patch to another, and that human-assisted pollination is often needed to make up for a lack of interest among the local flies.

Next year, Steven won't have to travel to South Brunswick in search of a "house of reputed pawpaws", because by chance I found a fine potential mate in the backyard of another friend, behind the Jewish center just a quarter mile away. It's a splendid specimen, thirty feet high, sporting perhaps a thousand flowers.

But pawpaw growers shouldn't have to depend on chance discovery. There needs to be an internet dating service for fruit trees. Sometimes it takes a village, or at least a good network.

Update, June 9: Just met a neighbor named Joe who has replaced the lawn in his side yard with four varieties of pawpaw and a lot of mulch. He says that wild pawpaws are common in Maryland, that raccoons and squirrels may be repelled by the bad-tasting skin of the fruit, and that it's easy to emerge from wild pawpaw patch with large buckets of fruit. I did not ask about any encounters with Susie, or if Marylanders are more adept at doing the hulu.


Some interesting links:

http://apiosinstitute.org/asimina-triloba-pawpaw

http://www.hort.purdue.edu/ext/ho-220.pdf

Another Perilous Embrace--Wisteria and Horse Chestnut

It's almost like someone chose to plant horse chestnuts in front of Princeton's Monument Hall knowing that their blooms would coincide with Memorial Day ceremonies. Here, while taps is being played, one of the first African American marines, Wallace C. Holland, Jr, salutes, and fellow veteran and guest speaker Elana Duffy (under the bell of the horn) looks on.

Meanwhile, elsewhere in Princeton, in front of a home where Thomas Jefferson reportedly stayed when Princeton was briefly the nation's capital, another horse chestnut has less in the way of freedom to celebrate. The blue flowers are of a wisteria vine that's been steadily consolidating its claim to the tree's infrastructure.

From a distance, the scene looks like this, with the wisteria each year adding weight while reducing the tree's access to solar energy to maintain its strength. The effect is pretty, but we'll see how long the tree can take it.

Unlike the American colonies, the tree has no way to free itself of oppression.

Fringe Tree for Pink Relief

Having first encountered fringe tree in North Carolina, I wondered if one I bought at a nearby nursery would make it through our deeper than usual New Jersey winter. They take their time showing signs of life in the spring, but this one finally burst forth with leaves and lacy white flowers. In time, it will reach the size of a large lilac or small flowering dogwood.

Meanwhile, the Rhododendrons in town, those that made it through the cold and survived the deer, look like big, bold pink dots in the landscape that really could use some sort of foil. The white flowers of black locust are too high up to offer contrast,

but the fringe tree is down at the right level, blooming at the right time.

It's dioecious, meaning "two houses", meaning there are male and female plants. The males are said to be somewhat showier. Here's a link for some medicinal aspects.

I've encountered fringetree only once in the wild, which is one time more than some other natives in the horticulture trade, such as oak-leafed hydrangia, bottlebrush buckeye, or purple coneflower. The wild fringe trees were on a north-facing slope in North Carolina, with soils influenced by diabase rock similar to what we find on the Princeton Ridge. Being less exposed to direct sun, soils on a north-facing slope are cooler and slower to dry out.

One approach to gardening with mostly natives is to learn what species a plant like fringe-tree is likely to be found with in the wild, then bring some of those species together in the yard. It can be satisfying to have a plant growing in the context of its natural associations, as art museums do when they display a painting not in isolation but in the cultural context within which it was created. Or, one can think more in terms of color and timing, using the fringe tree as well-timed pink relief in a neighborhood dotted with Rhododendrons.

Trenton Times Article on Veblen House

The Trenton Times ran a front page article today, Sunday, on the Veblen House and the Rogers House--another county-owned historic building that has fallen into disrepair. (It's early morning, and I first wrote "fallen into repair". Wouldn't that be nice.) Veblen House is part of Herrontown Woods, the first 95 acres of which were donated by the visionary mathematician Oswald Veblen and his wife Elizabeth to Mercer County. They intended the house to be given a public use, but the county rented it out until 1998, then boarded it up.

The Trenton Times article brings much-needed attention to the issue of saving government-owned historic buildings. Those that fall off a government's priority list tend to be left unprotected, even when a low-cost intervention like patching a small hole in a roof would add many years to their longevity. Fortunately, the Veblen House has a metal roof that has kept it protected through these many years.

The online version of the Trenton Times includes a series of twelve photographs of the house and cottage. For years, there's been an ongoing confusion about which house is which, so I've added a post entitled "Will the real Veblen House please stand up".

Though the Veblen House doesn't look like much from outside, it's a fascinating, one-of-a-kind house, given added dimension by its peaceful wooded setting on the edge of the preserve, and the extraordinary career of Oswald Veblen. News about work on trails and habitat at Herrontown Wood can be found at https://www.facebook.com/FriendsOfHerrontownWoods. Work on putting a nonprofit together to rehab the house and cottage is coming along, and the Rotary Club of Princeton has been holding monthly workday Saturdays at the Veblen House grounds.

Black Locust Caught in Perilous Embrace

All dressed up and nowhere to go (but down). High above our earthbound meanderings, black locusts have been casting their white blooms against blue sky. These particular specimens, across the street from us, have trunks dressed up in the nicely contrasting green of english ivy. The effect comes at a price, however. The ivy adds to the weight of the trees during ice storms, and adds resistance during high winds, either of which can cause this to be a short term relationship, resulting in the trees' premature demise. A previous post shows the consequences.

Around the corner, one of my favorite specimens of black locust (Robinia pseudoacacia), a multi-trunked beauty along Hamilton Avenue.

A Flood-Ready Garden

This morning, Sustainable Princeton will host another in its excellent series of Great Ideas Breakfasts at the Princeton Public Library. This month's program is about water that comes through Princeton in all its forms: precipitation, runoff, drinking water, wastewater. I'll be leading one of the discussion groups, on the concept of resilient landscapes. Below are some photos of the stream that flows through my backyard during heavy, extended rains, and how I've harnessed that water to drive a productive and diverse habitat of native floodplain wildflowers, sedges, and (my daughter's contribution) ducks.

The water cometh from uphill.

In its path lies this normally tranquil scene, with a series of miniponds, a constructed stream channel, native sedges, rushes, and wildflowers building towards summer blooms, and a chicken.

After heavy rain falls steadily for a day or so, upstream soils become saturated and begin to shed any additional rainfall. The water begins to flow in from uphill neighbors' yards, bringing this ephemeral stream to life. When the rains stop, the plants will emerge unharmed and replenished, and a little of the runoff will have been held back, slowed down, by the series of check dams and miniponds.

Now looking towards the back of the property, a quiet "before" scene: our path to a little town park bordering our yard.

And a "during" scene, as rainwater runoff flows from the park into our yard, and gets redirected by a berm so that it will feed our ponds and then flow safely between two houses just down the slope from us.

Being ready to accommodate a flood also better prepares a yard for droughts. Slowing the water down allows an underground reservoir of moisture to form, sustaining trees and wildflowers through the dry times.

A "fillable, spillable" pond prototype--something of a mockup intended to give the ducks a place to swim during droughts. And, when the ducks have mucked it up the way ducks do, or when the mosquito wigglers appear, it can be easily tipped to spill and refill with clean water. Need to build a rock wall ramp on either side to provide ornament and also a means for the ducks to waddle up into the water.

The ducks love the heavy rains.

The chickens? Not so much.

A Neighbor With a Lot of Gall

Growing next to the sidewalk just around the corner is an eyecatching oddity. These should be leaflets of an ash tree's leaf, but instead they bear an uncanny resemblance to a butterfly's chrysalis.

This is a normal ash leaf, with a bunch of leaflets.

Here, the development of each leaflet has been altered to make the chrysalis-like structure. Sure looks like something should be living inside.

Open it up to find the midges living the good life, well protected by the distorted growth of the leaf, and with ample food to reach maturity in a month or so. The larvae drop to the ground, overwinter in the soil, then emerge in the spring as adults to climb up the ash tree in time to lay eggs in the emerging leaves. The midge injects the rapidly growing leaf with a hormone-like chemical that causes the leaf to grow in a conveniently distorted manner. (Nice description found here.)

The latin name for the midge, a kind of fly, is Dasineura tumidosae. Considerable internet searching yielded no common name other than "ash gall". Here's some more info.

One of the more common galls on ash is the ash flower gall, which can be seen in the canopy in the spring, before leaves emerge. Thinking back to our hike up Baldpate Mountain a month ago, I realized we had been looking up at an ash that looked like it had growths on the twigs high up, wondering what it was. Probably ash flower gall.

A question to be asked is how closely tied is the fate of all of these organisms to their host plant. If our ash species succumb over the next ten or so years to emerald ash borer, whose presence in New Jersey was documented for the first time this past week (more on this later), will all of these insect species find other hosts, or disappear along with the ash? A tree like the ash, which can develop considerable stature and grandeur, feeds an entourage of less charismatic creatures. At least one of them I can now count as a neighbor. 

Mowing (and Eating) Bamboo

Bamboo, once it reaches a house's foundation, can actually grow up under the siding. That's what happened next door, as a big patch of bamboo that was providing privacy between homes kept expanding.

Realizing his house was threatened, the landlord had it all cut down last year, but there's been no followup to prevent the bamboo from regrowing from the roots. Having dealt with invasive plants for decades, professionally and around the house, I've learned the hard way that the first large scale removal is not the end of the problem, but only the first stage of an extended battle. Usually, the invasive wins. People are highly distracted, while a plant like bamboo is focused 24/7 on growing. While these new shoots are still soft, however, it would be relatively easy to mow them all down, every few weeks until the roots finally run out of energy.

How tender grows the bamboo? Ask the Chinese man who scavenges bamboo shoots in the neighborhood and takes them back to his house for some stir fry. People's appetites could potentially play a role in bringing an unruly plant like bamboo into balance with the environment, but it would take a cultural shift, and consistent harvesting year after year.

I sometimes speculate that cattail, a highly edible native that can aggressively take over a wetland to the exclusion of other natives, was kept in better balance long ago when it was part of people's diet.

Healthy Children, Healthy Planet--2014

The Riverside Elementary PTO brought the country to the people last weekend, for their annual environmental fair and fundraiser. There was Dorothy Mullen--who with the help of many volunteers over the years has nurtured the Riverside gardens to their glorious state--announcing the winners of the raffle.

And a small herd of sheep whose wool was being spun into yarn just outside the pen. The sheep must have been wondering why humans don't just grow their own fur.

There were some fine exhibits by the Friends of Princeton Open Space and the Princeton Schools Garden Initiative, some crafts, a plant sale, a yoga clinic...

My table, despite being stocked with info-packed books and pamphlets with compelling names like Rain Garden Manual of New Jersey, the Princeton Environmental Resource Inventory, and Princeton's Guide to Leaf Management, lacked a certain charisma until Dorothy's chickens arrived.

Kids related to the chickens in different ways. This boy lingered and gazed at them with a deep curiosity,

while others took particular pleasure in holding one. This chicken, named Buttons, being held most happily by a girl named Muktaa, is one my daughter brought to the fair from our countrified backyard on Harrison Street. (Thanks to Karla Cook for this photo.)

The event, riding the tide of a perfect day, raised $6000 towards sustaining the garden education programs that have become an important part of school curriculum.

In the words of lead organizers Beth Behrend and Julie Capozzoli, the event helps "provide all of our children with lifelong lessons in nutrition, healthy living, sustainability, hands-on learning and much more"

A Carolina Wren Family in the Carport

Carolina wrens have been dominating the airwaves around the house this spring. It took me back about twenty years to when there was a very long winter in Michigan. In Ann Arbor, low grey clouds can stream overhead for weeks on end, and by March the drab landscape of grey sky and brown landscape leaves everyone color deprived. I got so desperate for some sign of spring that I went to the library and checked out recordings of birdsongs. Some sort of bonding must have taken place, because for several years after that, I wrote little tunes based on birdsongs. It was nice of the birds to donate their melodies for the purpose, without any copyright restrictions.

The first piece I wrote was based on the song of a Carolina Wren. If you play the slideshow/recording below, you'll hear that a Carolina wren in Michigan sings four triplets in a row. In our Princeton backyard, the wren was doing five. Maybe the east coast wrens are more packed in, and feel a need to go on a bit, to let everyone know who's who and where's where.

A few weeks ago, we started hearing some peeping in the carport as we entered the house, but couldn't figure out where it was coming from.

I finally pulled out a ladder, and started looking in various places above the door.

You can see the orange inside of their mouths, ready and waiting for dinner.

Four, I think.

Around the time I got to wondering when they'd fly, the peeping stopped, and a quick scan of the driveway outside the carport revealed one young wren trapped in the back of the pickup truck, having made its first flight but not quite ready for its second.

The parent was close by, keeping an eye on me.