Sunday, October 4, 2015

The Visiting Oaks

We have so many native oaks in Georgia that folks don’t usually need to turn to others when choosing trees for their landscapes. Still sometimes people do, particularly if a landscape designer is involved and wants to use something unusual (although lately it seems like using a native better fits the goal of using something unusual as so many landscapes use the same non-native plants over and over).

Bur oak (Quercus macrocarpa)

I came across an unusual oak recently and, while it is native to the US, it is not native to Georgia. I was in the parking lot of a restaurant not too far from me and spied some large acorns on the ground. They had a noticeable fringe around the outer edge of the cap, so that really got my attention.

There are two oaks that have a fringed look:  bur oak (Quercus macrocarpa) and sawtooth oak (Quercus acutissima). Neither is native to Georgia, but bur oak can be found in Alabama, according to USDA. Sawtooth oak is native to eastern Asia and was brought to the US as an ornamental or as a wildlife food source.

Sawtooth oak (not native to US)

I have occasionally found sawtooth oak in parking lots, even just a few miles from this one. The leaves are noticeably different than what I was seeing here. They are long and slender with jagged teeth.

The bur oak has lobed leaves and a considerably larger acorn. The ones that I examined were almost square: equally wide as they were long. The biggest bur oak acorn was 2.5 inches by 2.5 inches (with the cap still on).

Quercus macrocarpa

I was excited to realize that I was actually seeing bur oak; I never expected to come across one of these in Georgia. It was surprising to see it being used as a landscape tree.

There were 4 trees in all and they were bearing a good crop of acorns even though it didn’t seem like they should be very old (that parking lot is about 15 years old). They ranged in size from 24-29 inches around (7.6-9.2 DBH) at 4.5 feet.

If you’d like to read some of my previous blogs about oaks that I have found in Georgia, here are links to them:


  1. Sawtooth Oak is still offered as a wildlife tree from NC Forest Service. A mystery to me when we have so many native ones to choose from. :o/

    1. I agree! Actually considered invasive at this point. Terrible tree -- and I love almost ALL trees. :)

  2. I love your parenthetical comment in the first paragraph and will start quoting it (with proper attribution) every time I give a talk on natives.

  3. I met the bur oak on the Green Prairie at the University of Wisconsin at Madison arboretum in June of 2013. There was one Bur Oak in the middle of the prairie. Our leader pointed out that this oak is extremely fire resistant, and when the prairie was burned several years previously, the bur oak was the only tree remaining. I checked "nature notes" from the arboretum for June 2015 - two years after I saw it and found the following :

    Finally we arrived at Greene Prairie, and what a wonderful surprise to see the open prairie! It had not been burned for several years and trees and shrubs (many of them native) had taken over the landscape. Fire is not the only management technique used to keep woody species under control. Last winter the brush was cut and this created a view we have not experienced for several years.

    Unfortunately the trail through the prairie was closed because of very wet conditions. However, we were able to walk on the boardwalk for a short distance. It was just enough to find some special flowers in bloom, including the pink orchid (Calopogon oklahmoensis). All of its pale pink flowers were in bloom. I use that character to distinguish it from C. tuberasa flowers that bloom sequentially. Check Ted Cochrane’s book Prairie Plants of the UW–Madison Arboretum for more information." The bur oak was gone. it was quite an interesting tree.