Slow Growing Oaks? Not Where I Come From

I just realized something (OK I should narrow that down because the sheer number of things I don't realize, or realize long after most people do, could - and in fact does - fill libraries).

My town of Northfield, MN was ravaged by Dutch elm disease in the late 1970's and early 1980's.  That means most of our boulevard trees date to around that time.  To Northfield's great credit a relatively small percentage of those replacement boulevard trees are green ash, especially as compared to other Minnesota cities.  The temptation in the early 80's to plant seedless green ash cultivars was great: no mess, "fast growth" and tolerance of the poor growing conditions that often exist between sidewalk and curb.  Everyone knew the risks of repeating the boulevard monoculture mistake of American elms, but all too many places went ahead and got ash-happy anyway.  And yes, with the arrival of the Emerald Ash Borer they will learn yet another hard lesson.

Even more to Northfield's credit is the relatively high percentage of oak trees that were planted on the boulevards to replace the elms.  Red oak, swamp white, white, bur and the occasional pin oak.  And they did a great job of mixing species on each block.

That means that in many, many instances oaks are planted next to sugar maples, red maples, lindens, hackberries and green ash trees - and that they were all planted at nearly the same time.  What a great way to put the old "slow growing oak" canard to the test!  What an idiot I am for not thinking about this 5 years ago when I first moved here!  So if oaks really are slow growing then the neighboring trees planted at the same time would be way taller by this time, right?

(Click to enlarge)

Wrong. Here's a typical Northfield boulevard, in this case looking west up toward the Old Main building on the St. Olaf College campus (the sledding hill that begins at Old Main is the site of my annual near-demise experiences).  In order you are seeing: northern red oak, sugar maple, green ash, northern red oak, little leaf linden.  If the green ash is the tallest it's only by the smallest of margins; perhaps 12 to 18 inches when viewed by my (admittedly biased) naked eye.  The next two tallest are the red oaks, then the sugar maple, then the linden. 

Now that I'm looking at our boulevard plantings in this way, I'm seeing this pattern repeated time and time again.  Oaks of all species (and in some cases indeterminate or in-between species) planted along side trees that have reputations for much faster growth - and the oaks are as tall if not taller.

It's frustrating that people continue to think of oaks as being slow growing, despite the evidence that's all around us if we only look and think.  Then again, I'm supposedly an urban forester and it took me five years to look and think... and see.

J. Russell Smith said oaks should sue poets for damages, for always and erroneously using them as a metaphor for slowness.  Of course suing a poet for damages is as potentially lucrative as suing a forester for damages.  Two words come to mind:  Blood and turnip.