Cornelian cherry dogwood

Spring arrives in Plainfield before the vernal equinox. Its coming is announced by the bloom of the mysterious yellow-flowered trees lining both sides of the Park Avenue entrance to Cedarbrook Park. Blooming with the earliest crocuses, these trees announce that winter is over and brook no argument. The best time to view them is in the morning, when the sunlight comes streaming over the rooftops to illuminate the yellow flowers and make them glow. It's a sight that enlivens many a morning commute. Surely these trees are one of the best features of Cedarbrook Park, which was designed by the Olmsted firm.

I have heard the trees identified as witch hazel (They're not.) Or spice bush. (Not that either.) Nonagenarian Barbara Sandford tells me that, when her children were very young, she taught them that the Cedarbrook Park trees were called Cornus mas (a.k.a. Cornelian cherry dogwood. Barbara has known that the trees were dogwoods for quite a while.) After I planted some Cornus mas in my own garden, I noticed that the Cedarbrook Park trees invariably flowered two weeks before my trees or anyone else's Cornelian cherry dogwoods. So my bet is that the Cedarbrook Park trees are not Cornus mas, but rather Cornus officinalis, a very rare bird and a close Japanese cousin to the European Cornus mas. Cornus officinalis is supposed to flower earlier than Cornus mas and berry later. Whereas Cornus mas berries in July, Cornus officinalis is supposed to berry in September. I have never gotten myself well enough organized to check for berries in September, though. This season I'll do it without fail.

A Cornus mas at 1785 Sleepy Hollow Lane was just beginning to bloom when I photographed it today, more than two weeks after the Cedarbrook Park trees opened their buds.

Both Cornus mas and Cornus officinalis berries look like bright red olives. They also resemble the fruits of Japanese Aucuba, which is in berry now.

Do your Aucubas make berries like these? If not, perhaps your plants are sex-starved.

This female Aucuba, lost in the depths of a shrub border in my garden, is right next to a male. Clearly, she is not lacking for pollen, as evidenced by this generous berry crop. Other female Aucubas not far away produce many fewer berries. With Aucubas, proximity helps pollination. Familiarity breeds berries. Perhaps the insects that pollinate Aucubas are not as wide-ranging as the honey bees that pollinate many of our flowers.

Unfortunately the only male Aucubas I have ever found for sale have leaves that are variegated. Having searched for years for plain green males without success, I gave up, bought variegated males, and hid them in out-of-the-way corners. Fortunately, Aucubas are among the most shade-tolerant plants, capable of growing almost in the dark, so the variegated males are quite easy to hide.(1)

The best-looking Aucubas I know in Plainfield flank the entrance at 972 Kensington Avenue.

Aucubas are at the northern limit of their hardiness in central New Jersey and can be killed back to their roots by an unusually harsh winter. I have seen most of Plainfield's Aucubas killed to the ground once in the last twenty years. They looked as though they had been struck by lightning and burnt to a crisp, reduced to small black cinders. Nothing looks quite so dead as a winter-injured Aucuba.

More on hollies

I wrote in my February 24 posting on hollies that I had heard complaints that the red holly hybrids, including 'Oak Leaf', were susceptible to winter injury in the Plainfield area. Peter Simone writes that there are two 'Oak Leaf' hollies just behind the low privet hedge and flanking the walk at his house at 1414 Watchung Avenue. Peter says that his hollies have not been injured by cold weather, but that deer have eaten a fair amount of one of them. Red hollies have softer leaves than many hollies, and when we think "soft", deer must think "tender".

There is an English holly at 937 Woodland Avenue. A smaller American holly is growing into it, making comparison between the two species easy.

There is an attractive blue holly hedge on Pine Street, alongside 1402 Watchung Avenue

(1) Perhaps my preference for plain green Aucubas is idiosyncratic. To be fair, I have to admit that variegated forms of Aucuba were introduced into cultivation in the United States three quarters of a century before green forms, so someone thought they were attractive (Michael A. Dirr, Manual of Woody Landscape Plants. Stipes Publishing Company 1998, p. 115.) In some places, variegated Aucubas are so much more popular than green varieties that plain green ones are hard to find. Around Lakes Como and Maggiore in northern Italy, where they grow 15 feet tall, Aucubas are used for hedging as commonly as we use privets here. I looked for and failed to find a plain green Aucuba hedge there several years ago. The lacustrine Italians want them variegated.

Copyright Gregory Palermo

Southern magnolia

Do you have doubts about climate change? New Jersey gardeners don't. As warming winters have threatened to make New Jersey into a southern state, its gardeners have started planting southern magnolias (Magnolia grandiflora) everywhere. In the 1980s, the only southern magnolias I knew of in Plainfield were at the former Memorial Funeral Home on East Seventh Street. Now East Seventh Street has seven southern magnolias within a length of just 300 feet. 1330 East Seventh Street at the corner of Coolidge Street is southern magnolia central.

Many varieties of southern magnolia are cold-hardy in New Jersey. The best known is 'Edith Bogue', named for Miss Edith Bogue of Montclair, NJ, in whose garden it first attracted notice. My experience with 'Edith Bogue' is that it is a rapidly growing, beautiful plant that has stayed green in winters that have browned my Nellie R. Stevens hollies and blackened my aucubas.

Some southern magnolia varieties that can be purchased at area nurseries aren't as cold-hardy. A particularly beautiful and tempting one is 'Little Gem'. It is a small tree with smaller leaves than those of most southern magnolias. Unfortunately, even rather mild winters can cause serious leaf burn. An example at 828 Arlington Avenue is pictured below after the winter of 2006-2007, not a very hard winter.

The tree is in much better condition this winter, which has been very mild so far, but this 'Little Gem' would probably be happier in Virginia.

Some of the varieties of southern magnolia that thrive in New Jersey have leaves with brownish, felt-like undersides.(1) A very handsome example is at 911 Woodland Avenue.

The Woodland Avenue tree shows a feature that is common in southern magnolias, the tendency to grow in a Christmas tree shape. European gardeners often take advantage of that tendency by treating southern magnolias as topiary specimens. Most southern magnolias that I have seen in European gardens have been formally pruned to form perfect cones. An exotic look that is well suited to an exotic plant; in Europe, southern magnolias are imports. I rarely see formally pruned southern magnolias in the United States, where the species is native. That sort of formal pruning is extremely high-maintenance gardening, by the way. It's very different from pruning a yew into a cone. Yews, with tiny leaves, can be shaped with shears. One can't prune southern magnolias with shears because their leaves are too large; the leaf fragments would be grotesque. Each stem must be cut individually with hand clippers.

Southern magnolias are capable of reaching great size in our climate. The grandest southern magnolia I have seen in the vicinity is at 221 East Westfield Avenue in Roselle Park. Twenty-five years ago, before the lower branches were removed, the house behind the tree was essentially invisible.

Magnolias are primitive trees. How primitive? Magnolias evolved more than 50 million years ago, before pollinators like bees and butterflies existed. Beetles are their pollinators.(2) The huge, white, lemon-scented blooms of southern magnolias might be the epitome of romance, but their intended audience is beetles, not you.

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A close relative of southern magnolia, but even more fragrant, is sweetbay magnolia (Magnolia virginiana). I have some sweetbay magnolias in my garden, but I would be grateful to hear of any examples of this species that can be seen from the street.

(1) There is apparently some correlation between brown leaf undersides and cold-hardiness (Manual of Woody Landscape Plants, Michael Dirr. Stipes Publishing Company 1998, p. 598). That correlation doesn't work for 'Little Gem', however.

(2) Magnolias, J.M. Gardiner. Globe Pequot Press 1989, p. 14.

Copyright Gregory Palermo

English holly

Location, location, and location! The beautiful, glossy-leaved English hollies (Ilex aquifolium) that we so highly prize (and rarely see) here are regarded as invasive pests on the west coast. English holly is a rarity in Plainfield. The only examples I know that can be seen from the street are two plants at 1332 Prospect Avenue.

English hollies have never been very commonly planted in the northeastern United States because they are considered insufficiently cold-hardy. They used to be seen occasionally in nurseries in this area. Now I almost never see English hollies for sale at all. They have been pushed aside by crosses between English holly and other holly species. One of those hybrids, Nellie R. Stevens, is by far the most abundant tree-form holly at the nurseries. There are two attractive Nellie R. Stevens hollies in front of the First Unitarian Society on Park Avenue near Seventh Street.

Nellie R. Stevens is thought to be a hybrid of English (Ilex aquifolium) and Chinese (Ilex cornuta) hollies. The original was found in the garden of Nellie R. Stevens of Oxford, Maryland. Nellie R. Stevens' big advantage is that it grows fast. It has a distinctive, glossy, blue-green leaf that is quite attractive. Its red berries are tainted by orange, but it makes up for that weakness by producing berries even in the absence of a male plant to fertilize it. Such berries are sterile.(1) Nellie R. Stevens' real failing is that it is even less cold-hardy than English holly. In three of the last twenty years most of this area's Nellie R. Stevens hollies have had their foliage completely killed by winter cold and wind. Most of the leaves fell off, and those that hung on were brown. The plants weren't presentable again until July, if then. I have planted dozens of Nellie R. Stevens over time, but I gave up on them completely after seeing most of them defoliate two winters in a row a few years back. This is a problem that global warming will solve, and the forward-looking local nurseries promote Nellie R. Stevens tirelessly. Pictured below is minor leaf injury from the 2006-2007 winter, a relatively mild one.

Ilex cornuta, the other parent of Nellie R. Stevens, is rare in Plainfield (because of cold-hardiness concerns). I know of only one, at 1215 West Fifth Street.

I haven't observed the West Fifth Street holly after a hard winter. Its very handsome foliage, with most leaves single-spined, is pictured below.

'San Jose' holly is the most commonly available among the crosses between English and Perny hollies (Ilex x aquipernyi). The leaves are dark blue-green, glossy, thick, and stiff. It's hard to imagine a deer wanting to eat any of them. 'San Jose' hollies are resistant to winter as well as to deer. I have never seen winter injury on a 'San Jose' holly in the Plainfield area. The berries are large and pure red. 'San Jose' hollies grow slowly. Their branches tend to get droopy if the plants are shaded. There is a 'San Jose' holly (or other closely related Ilex x aquipernyi hybrid) at 950 Hillside Avenue.

Blue hollies (Ilex x meserveae) were bred on Long Island by Kathleen Meserve specifically to produce glossy-leaved hollies that could tolerate cold winters.(2) They perform that function quite well. But they want to be shrubs, not trees. You can buy them pruned to a tall and narrow shape, and I imagine that it's possible to maintain that form if you're diligent. These plants are most often seen sheared into mounds. Their beautiful blue-green leaves are softer and flatter than many holly leaves, and deer are more willing to eat them.(3)

What about the so-called red holly hybrids that have been available for the past several years? The foliage is glossy and beautiful, but I hear reports that they are subject to winter burn in our area unless planted in a sheltered spot.(4)

All of the hollies mentioned above have their advantages, but if I had to choose just one of them for this locale, it would be straight English holly. I have grown several varieties of English holly in my garden for more than 20 years and have never had problems with winter damage. No holly has more beautiful foliage than English holly. It is a shame that it has largely disappeared from the local market. The English holly variety 'Angustifolia' is pictured below.

(1) Unlike Komodo dragons (Birds Do It. Bees Do It. Dragons Don't Need To, Neil Shubin, New York Times, Feb 24, 2008, http://www.nytimes.com/2008/02/24/opinion/24shubin.html?_r=1&oref=slogin ), Nellie R. Stevens hollies are incapable of virgin birth. The berries that Nellie R. Stevens hollies produce in the absence of a male pollinator are seedless and incapable of generating new plants.

(2) Kathleen Meserve also bred 'China Girl' and 'China Boy', shrubby hollies that share some parentage with blue hollies. They are more tolerant of the heat than the blues are. To my eye, their foliage is much less attractive than blue holly foliage, and I wouldn't find much use for them in the Plainfield area. (To judge from the numbers of them that I see at local nurseries, my opinion is not widely shared.)
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(3) Landscape Plants Rated by Deer Resistance, Pedro Perdomo. Peter Nitzsche, and David Drake. Rutgers Cooperative Research and Extension, New Jersey Agricultural Experiment Station, Rutgers, The State University of New Jersey 2004. http://njaes.rutgers.edu/pubs/publication.asp?pid=e271
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(4) 'Festive', 'Cardinal', 'Oak Leaf', 'Little Red', 'Robin', and others. Called red hollies for the reddish color of their new growth, they are widely available in local nurseries. I don't know of any that are visible from the street. Cory Storch is growing a 'Cardinal' in a sheltered spot in his garden; he reports that it is doing quite well. Claudia Heffner, a Master Gardener and landscape designer from Scotch Plains, reports that 'Oak Leaf' hollies planted in her garden have suffered significant leaf burn in winter. An 'Oak Leaf' that she planted in a sheltered spot in another garden is doing fine.

Copyright Gregory Palermo

American holly

Are you tempted to dig out that holly seedling that sprung up in your garden and transplant it to a prominent location? Not a good idea. It's unlikely to turn into a good plant. If you want a holly, buy one. American holly varieties are selected to meet stringent criteria.(1) Many are culled, but few are chosen. Professor Elwin Orton of Rutgers, one of the best-known holly experts in the United States, laid out his criteria for selection in a lecture to a group of amateurs that I heard several years ago. In addition to the regular, Christmas-tree shape and dense foliage we all expect, Orton wanted lustrous, dark green leaves. In female plants he insisted on abundant, large berries that color bright red early in the season without a hint of orange. Quite a demanding set of criteria to meet. Rather than conforming to the Ortonic Idea of a holly, your dug-up seedlings are likely to turn into spindly plants with dull grey-green foliage and lackluster berries.

Who could complain about the berries on the American holly in the tree lawn in front of 201-203 East 9th Street near Third Place? They're beautifully red and phenomenally abundant. The plant is one of three American hollies used as street trees at that corner.

Berries from the East Ninth Street tree, pictured at the top of the page, make you think it's Christmas in February. People have been using holly as a seasonal decoration as far back as the time of the ancient Romans. Christianity borrowed the use of holly from the Romans, who used it in their December Saturnalia celebration.

Hollies aren't very commonly used as street trees in this area. Savannah is famous for its American hollies and Foster hollies (an American holly hybrid) planted along the streets, but I can't recall seeing them used in any numbers in New Jersey towns. Three more American hollies are used as street trees on Park Avenue near Seventh Street.

Two large and handsome American hollies are at 825 West Front Street. I would be curious to know what sort of equipment the owner uses to formally prune such large plants.

Another beautiful American holly is at 1122 Hillside Avenue. This tree's foliage is dense, even though it hasn't been sheared, because it gets plenty of light. Hollies in the wild are typically less dense than this. They're an understory species, and in low-light conditions hollies have fewer leaves.

Foster hollies (Ilex x attenuata), naturally occurring hybrids of American holly (Ilex opaca) and another holly species, can be found in nurseries in this area if you look; they're certainly not common. They're not as cold-hardy as American hollies. The most common version seen here is Foster #2, which does fine in our climate. The only examples I know in Plainfield are in my own garden. Unfortunately, they're not visible from the street. If anyone knows of a Foster holly visible from the street, I would be glad to hear about it. (I'm also on the lookout for photogenic examples of English holly, Nellie R. Stevens holly, San Jose holly or close relative, longstalk holly, blue holly, or any unusual holly.) Foster hollies are recognizable by their narrow, delicate leaves, pictured below.

(1) Holly fanciers have selected probably thousands of named American holly varieties (clones). Hollies, The Genus Ilex, by Fred C. Galle (Timber Press 1997) provides individual descriptions of hundreds of those varieties. I counted 27 descriptions of varieties with names beginning with "A" alone. A more easily usable guide to the hollies is Hollies, A Gardener's Guide, published by the Brooklyn Botanical Garden in 1993.

Copyright Gregory Palermo

Beech

Or shall I rather the sad verse repeat

Which on the beech's bark I lately writ?
--- Virgil(1)

Did you think that carving words in beech bark was the invention of modern vandals? Not so. The smooth bark of beech trees has been used as a writing surface for millennia. Our word book comes from Old English boc (writing tablet), which derives from Old English beece (beech).(2) The most famous beech inscription

D. Boone

Cilled a Bar
On Tree
In Year 1760.

is preserved in a museum in Louisville.(3) The tree on which it was carved fell in 1916 at about 365 years of age. But, please, let the time-honored tradition of beech-carving die. Once the beech's thin bark is breached, the tree can be invaded by fungi that cause bark disease and heart rot. (4)

Plainfield has numerous beautiful beeches of two species, American (Fagus grandifolia) and European (Fagus sylvatica). There is a fine American beech at 975 Glenwood Avenue.

As this tree shows, beeches can be as beautiful in winter, when their smooth bark is most evident, as they are in summer. Another handsome American beech is at 1515 Charlotte Road.

Beeches hang on to their withered leaves long after most deciduous trees are bare, as shown by the Charlotte Road beech, which was photographed November 25. American beeches typically don't get the attention that their close relatives, European beeches, receive. European beech exists in dozens (hundreds?) of varieties (clones) selected for leaf color and shape. Copper beeches are European varieties. So are the much rarer cutleaf beeches. American beeches have toothed leaves. Teeth are lacking from the Europeans.

The massive European beech pictured at the top of the page is at 996 Central Avenue at the corner of Randolph Road.

Another handsome European beech is at 1077 Hillside Avenue.

1424 Prospect Avenue also has a very fine European beech.

Why aren't beeches used as street trees? They don't grow well when their root systems are restricted or where the soil is compacted by foot or vehicular traffic.(5) Beeches cast dense shade in which it is almost impossible to grow grass. They're at their best used as specimen trees in a large space.

Dan, a blogger from Spain who does a tree blog in English, wrote to point out that he had photographs of pine nuts on his blog. The photographs are great.
http://tree-species.blogspot.com/search?q=pine+nuts
He also gives a step-by-step pictorial rundown of what he had to do to collect the cones, extract the nuts, and remove various protective layers. Read his posting and you will know exactly what to do should you encounter a pine cone from a stone pine, the source of most of the world's commercial pine nut crop. (You will also understand why you pay so much for the nuts at the grocery store.)

(1) cited in A Natural History of North American Trees, Donald Culross Peattie, Houghton Mifflin Company 2007, p. 163.

(2) Dictionary of Etymology, Robert K. Barnhart, ed., The H.W. Wilson Company 1988, p.106.

(3) Native Trees for North American Landscapes, Guy Sternberg with Jim Wilson, Timber Press 2004, p. 181.

(4) Trees of Pennsylvania and the Northeast, Charles Fergus, Stackpole Books 2002, p. 103. Fergus catalogues a large number of wild animal species that use beech nuts as food. Donald Culross Peattie, cited above, quotes Audubon at length on beeches and the now-extinct passenger pigeon.

(5) The Trees of Union County College, Thomas M. Ombrello, Union County College 1997, number 10.

Copyright Gregory Palermo

White oak

Is this the tree that launched a thousand ships? It is indeed. White oak, an American native, reached the pinnacle of its maritime glory during the War of 1812. The white oak planks of the U.S.S. Constitution repelled British cannonballs so well that the ship became known as "Old Ironsides". After a few encounters with the Constitution and its sister ship, the British admiralty forbade its frigates from engaging the American 44-gun frigates in single combat.

William Bryant Logan relates the story of the U.S.S. Constitution in his 2005 book Oak: The Frame of Civilization.(1) Mr. Logan claims a central role for oak (not just white oak) in human development. He reviews evidence that early man was dependent on acorns as a staple food and presents a map showing the distribution of oak trees to be conterminous with the locations of settled civilizations in the northern hemisphere. You already knew, no doubt, that oak made durable furniture, sturdy ships, and watertight barrels. Did you also know that oak galls made ink and that oak tannins tanned leather? Did you know that oak was used in shipbuilding even before it helped Jason and the Argonauts find the golden fleece? Mr. Logan lays out all these details of mankind's reliance on oak in his informative book.

Oak is a complicated genus. There are as few as 250 or as many as 600 species of oak, depending on whose classification you accept. To complicate life, many oak species interbreed with one another. Oaks are conventionally divided into two groups: the white oak group with white oak as its most typical species, and the red oak group with red oak as its exemplar. The white oak group has leaves and leaf lobes that are rounded. The red oak group has leaves and lobes that end in points with bristle tips.

Acorns of the white oak group mature in one growing season; the reds require two seasons. White oak group acorns have a lower tannin content than the reds. The tannin content difference represents divergent survival "strategies". Tannins protect acorns by imparting a bitter taste and by interfering with animals' protein digestion. Squirrels are quite tuned into differences in tannin content. They eat white oak acorns immediately and bury reds. With less tannin protection, acorns of the white oak group are obliged to begin to grow shortly after contacting the ground in the fall. If the squirrels don't eat the white oak acorns immediately, it's too late. The squirrels can permit the very tannic and slower-to-sprout acorns of the red oak group to marinate underground during the winter.(2) People can eat acorns any time they care to do so by leeching out the tannins with water. Recipes abound on the Internet.

The grand white oak at 1310 Central Avenue pictured in leaf at the top of the page and leafless below is 5 or 6 feet in diameter. Surely well over a century old. Sadly, one sees limbs lopped at the property line on the left side. (There ought to be a law.) The tree illustrates the characteristic white oak habit and the vast spread of a mature white oak's limbs. The spread limits the species' use as a curbside planting.

Another fine white oak is at 705 Ravine Road.

Most white oaks are easily recognizable in the winter by their blotchy bark. The blotchiness is caused by an apparently harmless fungal infestation.

Xavier Canela sends word from Spain that he has a blog about the trees of Barcelona: http://arbresdebarcelona.blogspot.com/ The blog is in Catalan. If you can read one of the Romance languages, you can understand it without much difficulty. One of his posts regards Pinus pinea, the source of most of the pine nuts on the market and probably best known as the pines of Rome. (The pines of Rome, it turns out, are natives of Iberia.)

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(1) Oak: The Frame of Civilization, William Bryant Logan, W.W. Norton and Company 2005, pp. 230-249.

(2) A Field Guide to Eastern Forests, John Kricher and Gordon Morrison, Houghton Mifflin 1998, p. 84.

Copyright Gregory Palermo

Tulip Trees

Tulip trees reserve their charms for those who seek them out. Demure in all seasons, tulip trees are now discreetly displaying their unusual fruits.

The fruits hang on into the winter even after dispersing their winged seeds into the wind. Spring brings the "tulips", pale yellow blooms tinged with orange and green. Their unassertive colors can blend into the foliage and fail to catch your eye. But when you spot the flowers unexpectedly you are rewarded with the feeling of having discovered a secret.

Once you have seen a tulip tree leaf, you will never mistake it for that of another species. The distinctive shape has been described as that of a maple leaf with its tip cut off. The leaves turn a handsome yellow in the fall.

There is a massive and beautiful tulip tree at 443 Stelle Avenue near the corner of Field.

A tulip tree at 1001 Central Avenue illustrates two of the species' most typical features: a long, straight, slightly tapered trunk with no branches near the ground and a rather narrow crown. The form is distinctive enough that tulip trees can be recognized from a distance even when they are leafless.

970 Hillside Avenue provides another example of a mature tulip tree.

Tulip trees are also called tulip poplars or yellow poplars. In fact, they're neither true poplars nor closely related to the poplars (genus Populus). In the lumberyard, however, tulip tree wood is called poplar and is commonly sold for use as interior trim. The wood is among the lightest in weight of the hardwoods and is not particularly strong.

Tulip trees grow fast and become huge. In a favorable environment they can grow to 200 feet tall with ten foot diameter trunks.(1) Their massive size and weak wood make them susceptible to damage by high winds. For that reason tulip trees are not often used as street trees.

Light and easily worked wood can have advantages, however. Tulip tree trunks were hollowed out by several native American tribes to make canoes. It is said that Daniel Boone took his family and belongings down the Ohio River in a sixty-foot tulip tree canoe, abandoning Kentucky for the Spanish Territory in the late 1700s. (2)

(1) Trees of Pennsylvania and the Northeast, Charles Fergus. Stackpole Books 2002, p. 148.

(2) A Natural History of North American Trees, Donald Culross Peattie. Houghton Mifflin 2007, p. 260.

Copyright Gregory Palermo