Sunday, March 23, 2008

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


Anonymous said...

Cedar Brook not Cedarbrook

Anonymous said...

I've always thought those trees in Cedar Brook were big witch hazels. Now I finally know.

I love your blog, Greg. Keep writing.

Tim Kirby

Anonymous said...

While not necessary on point to your lovely pictures, but as an aside, what are your impressions on the butchering job done about two/three months ago by what appeared to be a sub-contractor for pse&g cutting back trees around utility wires? Were the blindfolds standard or optional?

Bewildered Tree Hugger