Tree Seedlings Everywhere, But Not a Street Tree To Plant

There's irony to be savored, or puzzled at, while pulling out the hundreds of trees sprouting through the woodchip mulch in my yard. The tradition of Arbor Day, which slipped past this year on April 29, is to encourage people to plant trees. Free trees are distributed, often spruce seedlings--a species more likely to be found growing naturally in cooler latitudes. Planting a tree is often mentioned as a small, partly symbolic but meaningful way to counter global warming. While serving on the Shade Tree Commission, I did some math and figured out that the 50-100 street trees being planted in Princeton were not even coming close to replacing the 250 trees being lost each year. The 2-3" caliper trees deemed most likely to survive and prosper cost $250 each, eating up the budget.

Clearly, there's a perceived and sometimes real need to nurture trees, and there's pleasure in watching a tree, planted in the right spot, grow with deceptive speed towards towering heights. What, then, to make, in meaning and utility, of these hundreds of red oak seedlings rising from the earth each spring?

Or the elm seeds that carpet the patio,

filling the drain,

and making an improbably lightweight but effective dam that needs to be cleared for our low-budget drainage to work. Thousands, perhaps millions, of achenes will soon follow, spinning earthward from the maples--red, silver and sugar--adding another layer of trees-to-be, and trees-to-be-pulled.

Those Arbor Day tree giveaways are a tradition that likely dates back to early in the past century, as fields slowly shifted back to forest. Now, with reforestation long since accomplished, trees in this neighborhood, at least, hardly need our help. When it comes to reproduction, they don't fool around, which is to say, fooling around is what they're doing a whole lot of.

The issue is more a matter of how to get the right tree growing in the right place. There is no lack of gaps in the street canopy to fill, no lack of parking lots where cars bake in the summer sun for lack of shade. And no lack of trees, free for the transplanting. There's also no lack of logistical issues--getting permission to plant them, hemming and hawing about which species would be best, watering the first year and protection for a few years after that, and so forth. Meanwhile, the trees are showing us how its done, on their own. So simple, and yet so much conspires to keep our world just as it is, filled with persistent problems side by side with an abundance of solutions. If future generations can find sustenance in irony, they will surely prosper.

Native Trees of Princeton

An attentive reader commented that the page for "Native Trees of Princeton", which I thought I had added along the top of the homepage, does not exist. Funny, I clicked on the "publish" button but the list of trees refused to publish, nor did it magically publish itself during the ensuing weeks when my mind was on other things. Maybe Googles ever more sophisticated software detected that it still needed work, which is to say it was a bit "drafty".

Here it is, nonetheless, published as a post rather than one of those enduring "pages" at the top of the blog. It was created as a step towards fleshing out, or foliating, a rather bare tree list we have on the Princeton Shade Tree Commission website.

My apologies to any native tree species not included here. Please speak up. Catalpas, we'll talk.

ATTRIBUTES OF SOME NATIVE TREES IN PRINCETON 

This is an extensive but informal list of native trees you may encounter in the wild or in your yard, with some description, based on ten years of observation. 

Acer negundo (box elder)--Grows wild. Not commonly planted. It's soft wood can provide good habitat for birds. Considered messy and not very well formed.

Acer rubrum (red maple)--A durable, very commonly planted street tree. Also common in the wild.

Acer saccharinum (silver maple)--Common in yards and in the wild. Not often intentionally planted. Has a reputation for dropping limbs, but performs well in many yards, providing an attractive, open shade.

Acer saccharum (sugar maple)--Less common, but a sturdy, attractive native.

Amelanchier canadensis (shadblow, shadbush, serviceberry, Juneberry)--A very small tree or large bush. White flowers early in spring, supposedly when the shad are surging up the Delaware. Berries edible, but frequently attacked by cedar apple rust, so don't get your hopes up. Even our resident catbirds were disappointed.

Asimina triloba (pawpaw)--Small tree, up to thirty feet. I heard there's a wild stand behind someone's house down across Carnegie Lake, and a substantial patch in a park over in Cranbury. Plant more than one to increase prospects for the often elusive fruit. They clone, so best planted where there's a little room to expand.

Betula lenta (cherry birch)--Grows wild along the Princeton ridge. Not commonly planted in yards.

Betula nigra (river birch)--Beautiful bark and form, frequently sold with three trunks.

Betula (paper and grey birches)--These species are more characteristic further north.

Carpinus caroliniana (blue beech, hornbeam, musclewood)--Common along the Princeton ridge. Not often intentionally planted.

Carya alba (mockernut hickory)

Carya cordiformis (bitternut, swamp hickory)

Carya ovata (shagbark hickory)--Hickories are common in the wild, but not frequently planted.

Castanea dentata (American chestnut)--Devastated by the imported chestnut blight in the early 20th century. Only a few small specimens persist in the wild. The disease does not kill the root, which then resprouts. Backcrossing has developed resistant native varieties with a small percentage of asian genes, e.g. 1/16th Chinese. Some of these 15/16th native trees have been planted in parks and preserves in Princeton in an effort to reestablish the species. A few chestnuts grow along streets in Princeton, but are either Chinese or Japanese. The nut husks are very large and prickly.

Celtis occidentalis (hackberry, sugarberry)--Sturdy native, infrequently seen in the wild, underutilized in planted landscapes. They line Walnut Street across from JW Middleschool.

Chionanthus virginicus (fringe tree)--Very attractive flowers. Small tree/large shrub. Some evidence in Ohio that it can be attacked by emerald ash borer, but more evidence is needed before deciding not to plant.

Cornus florida (flowering dogwood)--Attractive small tree, commonly planted, with berries that provide important nourishment for birds migrating south in the fall. Fairly common in the wild, but an imported fungus has cut back on its numbers. It can be harder to establish that the Korean dogwood, whose fruit are eaten by monkeys in its native Asia.

Crataegus crus-galli (cockspur hawthorn)--Attractive small tree. Rarely found in the wild. Underutilized in planted landscapes, perhaps because of thorns.

Diospyros virginiana (persimmon)--Attractive mid-sized tree. Females bear fruit, which may be appreciated or viewed as messy.

Fagus grandifolia var. caroliniana (beech)

Fagus grandifolia var. grandifolia (beech)--Beech trees are common in the wild along the Princeton ridge, but are seldom if ever planted.

Fraxinus americana (white ash)--Princeton's most common tree, soon to be decimated by the arrival of Emerald ash borer. Though typically encountered in second growth forest, it can grow to a towering height, with a few extraordinary specimens to be found on campus and in older neighborhoods. Planting ash is discouraged, since all ash species will soon be dependent on chemical injections for survival. Anyone owning an ash they wish to keep should get it treated, with emamectin being the most frequently recommended insecticide to inject into the trunk.

Fraxinus pennsylvanica (green ash)--Usually found in wetter conditions, and less attractively shaped, than the white ash. Same susceptibility to emerald ash borer.

Gleditsia triacanthos (honey locust)--The wild variety has thorns and is rarely encountered, perhaps because it was spread by now extinct megafauna. The unripe seed pods have a sweet, edible inner lining. One large specimen can be found near the old gas station at Princeton Shopping Center. Planted varieties, such as those at the new Dinky station and Hinds Plaza, have no thorns, and provide a pleasant, open shade. The tiny leaflets conveniently disappear back into the lawn in the fall.

Gymnocladus dioicus (Kentucky coffee tree)--A remarkable tree, rarely found in the wild, for reasons similar to honey locust. Its very large compound leaves emerge late in spring, and drop early in fall, making the tree ideal for planting on the south side of passive solar houses. They were used in the landscaping for the Dinky parking lot.

Hamamelis virginiana (witch hazel)--Attractive small tree/large shrub. The native species flowers in late autumn, while asian species flower in the spring.

Juglans cinerea (butternut)--Rarely seen. Some are hybrids. The native species has suffered from the introduction of a fungal disease. Efforts are underway to bring back the butternut in Princeton, in parks and nature preserves.

Juglans nigra (black walnut)--Common in some wild areas, and in some backyards. Rarely planted, due to large nuts and the juglone compound emitted by the roots, which can suppress growth of tomatoes and other plants.

Liquidambar styraciflua (sweet gum)--Sturdy, large tree, common in the wild and sometimes planted intentionally. The "gum balls" it drops can be a drawback for some.

Liriodendron tulipifera (tulip tree)--Fast growing, long-lived tree that can reach great size. Flowers tulip-like and attractive, but usually too high up to appreciate. Common in the wild, but not typically planted intentionally.

Magnolia virginiana (sweetbay, swampbay)--Small tree. Can have attractive flowers. Not typically planted along streets.

Morus rubra (red mulberry)--The white mulberry (M. alba, nonnative) is also found in Princeton. A small tree. Bears abundant, edible berries similar in appearance to blackberries. The berries can be messy, and the tree lacks an attractive form. Very tasty berries, though, if you can reach them.

Nyssa sylvatica (black gum, tupelo)--Beautiful fall color. Sporadically encountered in the wild. Long-lived, sturdy. Is becoming more frequently planted along streets.

Ostrya virginiana (ironwood, hophornbeam)--Small tree. Not common in the wild, nor in the landscape trade.

Oxydendrum arboreum (sourwood)--Small tree with bright red fall foliage. Craggy form. Underutilized; may not be well adapted for the nursery trade. More common in the wild further south. Several specimens in Princeton, including one next to the church across from the high school.

Platanus occidentalis (sycamore, plane-tree)--Can be confused with the London planetree, which is a hybrid between two species, one of which is P. occidentalis. Attractive, large tree, with highly ornamental bark. Its more susceptible to anthracnose than the hybrid.

Prunus pensylvanica (fire or pin cherry)

Prunus serotina (black cherry)--The native cherries are attractive mid-sized trees typically found in earlier successional forests. They nearly rival oaks in the diversity of insects they provide food for, and so are very important for food chains.

Quercus alba (white oak)--One of the most majestic trees. The white oak "family" (those with rounded lobes, such as white oak, swamp white oak, and willow oak) are less susceptible to bacterial leaf scorch than the red and pin oaks (pointed lobes).

Quercus bicolor (swamp white oak)--Sometimes planted along streets.

Quercus coccinea (scarlet oak)--Attractive, but less commonly planted.

Quercus palustris (pin oak)--Very common street tree in Princeton. Its lower branches characteristically angle downward and often die back. Many are being lost to bacterial leaf scorch, which causes gradual dieback.

Quercus phellos (willow oak)--More frequently planted than in the past. More common in states further south. Its narrow leaves can form an attractive mulch, somewhat like pine needles.

Quercus rubra (red oak)--Common tree in the wild and along streets. Susceptible to bacterial leaf scorch.

Quercus velutina (black oak)--Encountered in the wild. Less commonly planted than red oak.

Robinia pseudoacacia (black locust)--Native to the Appalachians. Widely planted and naturalized elsewhere. Its wood is resistant to decay, it has attractive flowers, and can achieve a very attractive form with dark, craggy limbs contrasting with the foliage. Can be invasive in some habitats, and can clone, sending up young shoots armed with thorns. But some specimens in Princeton front yards are beautifully formed and well behaved.

Salix nigra (black willow)--Fast growing. Sometimes planted in low areas in the belief that it will dry the soil out.

Sassafras albidum (sassafras)--Attractive tree, common in the wild. Can clone, which may be why it's not commonly planted.

Tilia americana (American linden, basswood)--Attractive. Underutilized. Sporadically encountered in the wild. Linden trees along streets are generally not the native species.

Ulmus americana (American elm)--Though the elm was hit hard across America by Dutch elm disease, Princeton varieties have shown considerable resistance, allowing specimens to perform well and provide shade for many years, even though they may eventually succumb.

Ulmus rubra (red elm, slippery elm)


Native Evergreen Trees:

Ilex opaca (American holly, Christmas holly)--Attractive native, sometimes used in yards. Can grow eventually to 30 feet or so.

Juniperus virginiana (eastern red cedar)--Small tree. Useful in some situations.

Pinus strobus (eastern white pine)--Not encountered in the wild unless in planted stands. Its native range is to the north of Princeton. Can get big, and tends to drop large branches during ice storms.

Homage to the Next Generation of Trees

One fairly rare sighting, both in Princeton's woodlands and parks and along streets, is a young tree. The great Mercer Oak that was finally blown down after 300 years of life was replaced in 2000 with an offspring, but how about all the other trees that have been lost in recent years, and will be lost if the predictions of Princeton's recently completed tree inventory prove correct? Perhaps we've gotten out of the habit of planting trees, having long been spoiled by their abundance.

This blog takes all sides on trees, praising one tree, ruing another, finding tranquility in a deep forest or opportunity in the sun-filled opening a fallen tree leaves behind, and ever thankful for how they give both in life and death.

This post offers examples of young trees growing in auspicious locations, and all the wonderful work they are already doing.

First, I'd like to thank a neighbor for letting a volunteer red oak grow in a perfect spot to shade my driveway and pickup truck. They probably haven't even noticed it, but I do. Seems like just the other day it was a little sprig peeking over the fence.

And thanks to the folks, too, who paid for a tree to be planted in Potts Park to celebrate the birth of their son. We chose the spot carefully, wanting it to eventually shade the play equipment through the summer, but not be out in the field where it might intersect with a kid running after a ball. Many swings and play structures around the world are not being allowed to live up to their full potential, abandoned by kids when they overheat in summer for lack of a tree.

Another red maple, though perhaps better to have been planted on the house side of the sidewalk, is beginning to fill one of the many gaps along our streets. We need many more trees like this one to keep Princeton's pavement from baking in the summer. The more this tree shades and transpires, the less pedestrians will perspire.

Hard to believe that not long ago this pin oak and American elm were little two foot volunteer seedlings my neighbors transplanted to their front yard. Their faith in the growth force in modest saplings, and the remarkable way time has of passing, is quickly yielding a visual buffer and afternoon shade for their house.

This backyard tulip poplar was another volunteer transplanted to a spot well away from the house.

This young backyard white oak is doing a good imitation of Mercer Oak Jr. over at Princeton Battlefield. Just beyond the fence, in Potts Park, a grove of white oaks planted by the town has matured into a favorite spot for picnics and birthday parties.

Another friend has started a pawpaw patch in their "back 40",

and a fig tree bearing delicious figs in a protected spot next to the driveway.

Though ginkgoes don't support wildlife the way native trees do (a recent article in the NY Times reports that only a few insects feed on ginkgo, while an oak serves up food for more than 500 insect species), these stilty varieties are shading the way along an improbably narrow space over at the Princeton Healthcare Center.

I like to think that the proximity of young trees, with their dynamic growth happening at our level, puts us better in touch with an aspirational energy that can feed our own. When I hear Copland's Appalachian Spring, I think of young landscapes--prairies and early successional stages. In addition to the mature beauty of a forest, we need among us these renewing landscapes, these fresh beginnings, to feed our spirit.