Friday, January 8, 2016

Northern Pin Oak (aka, Hill's Oak, Quercus ellipsoidalis)

As long as I am pimping oak species.

Range map, by county, based on pollen samples.
I ran into an oak tree that keyed out to Quercus ellipsoidalis.  It is in the west corner of Eaton Rapids' Old Athletic Field (also known as Howe Memorial Park).  I was impressed by the prodigious production of acorns from a relatively small tree.

Northern Pin Oak is number five on this list of tree species found in Wisconsin Oak Savannas.  Notably, it is the second-least susceptible to fire damage, after Burr Oak.

Quoting extensively from the (US) Federal tree database:

Fire Ecology

Northern pin oak is well adapted to fire. The thermal insulating properties of the bark of mature trees allow it to survive even annual burning [24]. Smaller trees are easily damaged by surface fires but will sprout vigorously from the root collar or stump after top-kill.

Drought tolerance

Northern pin oak is an upland xeric species that commonly grows on dry, acid, sandy soils with a very thin organic layer. It most often occurs on sandy plains and sandstone hills, and develops into extensive pure populations only on such sites [9,10]. Northern pin oak is the most drought tolerant of all black oaks

Sounds like just the species for sites stripped of top soil and with gravelly/sandy sub soils.


Seed production begins when the tree is about 20 years old. Good seed crops are not produced every year and in the off years many of the acorns are destroyed by weevils [10,23]. Seed dissemination is by squirrels, blue jays, and gravity [16,17]. Vegetative: Northern pin oak sprouts from the root collar or stump if top-killed or cut (or burned)

Note from ERJ, seed production can be vastly accelerated by irrigation, weed control and fertilizer...nitrogen early, potassium after canopy fill.

General description

Northern pin oak is a small to medium-sized, native, deciduous tree, typically reaching heights to 70 feet (21 m) [14,21]. It has an irregularly shaped crown and low-hanging branches that persist for long periods as dead stubs, giving a ragged appearance to the trunks [9]. Northern pin oak has a deep taproot and deep widespreading lateral roots

One challenge of recreating oak savannas on a modest scale is producing a 10%-to-50% canopy with multiple trees that grow to enormous sizes.  Use of more diminutive species allows the scaling of the recreation of the Sun/Shade/Evaporative mosaic into a more modest footprint.  That mosaic creates a multitude of environmental niches and fosters a vast diversity of ground cover species.

Wildlife value

I harvested 70 pounds of acorns from that tree.  I gave most of them to The Captain whose grandson fired them with his slingshot, one-by-one, into his dad's cutover woods.  Every. One. Of. Them.  I talked to The Captain's son.  He had trail cams up.  The deer walked by the corn feeder to root out the acorns that the grandson had launched.

Of the ones I had left, the local Red Squirrels staged a Chicken Run on the garage and ate them all.

I fear that I will have to spend $9.00 a pound and buy them from Schumacher Seeds.  For those who are interested in purchasing trees, they are available from Itasca Greenhouse, Inc in Minnesota.  Q. ellipsoidalis listed near the bottom of the page.


  1. I have read the NPO name is a misnomer. It is most likely in the Scarlet oak clade.


    As we walked along we came upon a tree that I first thought was a black oak but luckily I checked the acorns on the ground and it turned out to be a Hill's oak which I measured to 11.70' x 90'. The height was from shooting straight up and it ties the tallest I've measured to date in Michigan.