Northern red oak vs. Scarlet oak

[Dodgy Loner]

Northern red oak and scarlet oak are two of the most easily confused oaks in the eastern U.S.  They share much of their range and many key characteristics, and they often occur together on the same site.  Both have relatively smooth bark, with shallow furrows and long, vertical white streaks between the furrows.  Both have large acorns and large, glabrous leaves, usually with 7-9 lobes.  However, by paying attention to a few key characteristics, it's quite easy to separate the two, even in the winter time.  WDH has already offered an excellent tutorial on scarlet oak, but I thought it might be helpful to see both trees side-by-side.

Northern red oak

A large tree, often 70-90 feet tall and 2-3 feet in diameter, although occasionally much larger.  The Georgia champion is in Sosebee Cove and measures 4.9 feet in diameter and 126 feet tall (guess who found it ).  Northern red oak is one of the most important red oaks for timber production, as it is usually a well-formed tree with a straight trunk:
 

In second-growth forests, however, it's easy to find heavily tapered, leaning trees with multiple trunks.  This is the result of profuse stump sprouting after the parents were harvested.  The white stripes on northern red oakbark usually extend down within 1 or 2 feet of ground level:
 

When observing the leaves of a northern red oak, it is important to consider whether they are sun leaves (from the crown) or shade leaves (from the understory).  The sinuses between the lobes of a sun leaf usually extend about halfway to the midrib (the main vein), and the petioles are often reddish:
 

In shade leaves, the sinuses are very shallow, and the petioles are rarely reddish:
 

The acorns of northern red oaks are usually more than 1" long, and they have a very small, saucer-shaped cap that covers less than 1/4 of the acorn:
 

Scarlet oak
Scarlet oak reaches approximately the same size as northern red oak.  The Georgia champion is an open-grown tree, 6.6 feet in diameter and 70 feet tall.  Forest grown trees sometimes reach 100-120'.  Form is usually considered to be poorer than northern red oak.  It often holds onto dead limbs for a long time and rarely grows straight:
 

However, form varies widely from tree to tree.  This scarlet oak is 3.5 feet in diameter, 120 feet tall, and nearly 70 feet to the nearest limb.
 

The white streaks on scarlet oaks usually stop around 6-12' from the ground.  Below this point, the bark is blocky:
 

The sun leaves of scarlet oak have very long petioles, and are deeply lobed, with the sinuses extending nearly to the midrib:
 

Shade leaves have shorter petioles and shallower sinuses.  The sinuses usually extend about halfway to the midrib, much like northern red oak shade leaves.  This is why it is important to consider where the leaves came from:
 

Scarlet oak acorns are usually about 1" long, with a bowl-shaped cap that encloses about half of the acorn:
 

[scgargoyle]

Thanks for the side-by-side comparison, DL, It certainly helps us newbies figger out what we have on our woodlot. From what you've shown, I'd say  my biggest trees are scarlets. Mine are up to 24" DBH, and nice and tall and straight. They're near the top of the hill- does that make sense? I've got several other oak sp., as well as a couple hickories. Our land is in SC, within spittin' distance of the mountains.

[Dodgy Loner]

Makes perfect sense, scgargoyle.  Scarlet oak prefers somewhat drier soils than northern red.  It's most common from midslope to hilltop.  On the hilltops, it'll outnumber northern reds by a wide margin.  Northern red prefers more mesic sites, from midslope right down to the edge of river bottoms (as long as it doesn't get its feet wet).

[WDH]

Excellent comparison, DL.  Northern Red Oak will compete better on an good site than will Scarlet Oak, so Scarlet is sometimes resigned to the drier sites with shallower soils. 

The lobes are a little different too.  There seems to be more bristle tips on Scarlet oak lobes than on Northern Red.  The Scarlet lobes seem to be more divided (developed) with the Northern Red being more simple and less divided.  That difference is easily seen in Dodgy Loner's pics.

[SwampDonkey]

Some of those shade leaves of Dodgy's scarlet oak sure look like the ones on my seedlings. And the fall foliage is much more brilliant red than my red oaks. We's gonna solve this mystery soon. 

[WDH]

SD,

I still think that what you have there is Northern Red Oak.

[Dodgy Loner]

I'm inclined to agree with WDH.  Those are prolly northern red leaves.  Seedlings are always sneakier than mature trees, though.

[SwampDonkey]

You guys aren't going to let me have my scarlet oak are ya's?   

[Dodgy Loner]

Kind begets kind.  Do you have any mature scarlet oaks in the immediate areas?

[SwampDonkey]

DL, no scarlet here. I am told there are some at Bear Island campground, where the seed are supposed to have been collected from. I will be investigating some more.  Scarlet is not native here. Not that it means anything, I have brought white oak seedlings from NH and I have a nice white oak on the lawn now. That was 20 years ago I planted it. 1 out of 3 survived.

[WDH]

We could send you some scarlet oak acorns if we could rescue any from the marauding squirrels .  Lanier Lurker probably has a sackful with all the scarlet oaks on his place.

[Lanier_Lurker]

There are many acorns under the "graveyard oak" in https://forestryforum.com/board/index.php?topic=26147.0

I could probably get some from there.

In my immediate vicinity I just have the 2 trees mentioned in https://forestryforum.com/board/index.php?topic=25020.0

There don't seem to be any acorns around them.  And I could not be certain they were scarlet if there were any - what with all the other oaks around.

[WDH]

The single tree in the graveyard would be a good choice because they would be easy to see and there would not be as many squirrels to nab them one by one as they fall.

[SwampDonkey]

I wouldn't collect those last years crop though. Wait for the new crop to ripen this year. I'm told the large nut trees have seed that is viable a short time. Just guessing, but by mid summer if they didn't germinate the warm temps have probably nuked the embryo. There are exceptions of course, but why not get fresh seed.

[Lanier_Lurker]

The "graveyard" scarlet oak did not make a nut crop this year - which is not surprising since it seems to have made a large crop last year.  Hopefully next year.....

Turns out I have more scarlet oak in my area than I realized.  Their brilliant fall color combined with their tendency to hold their leaves much longer than other hardwoods makes them really pop out this time of year.  I eventually found one that made a decent nut crop.  SD, we will try to get some acorns to you in time for spring planting.

[Phorester]

In Virginia, scarlet oak quite often has a swollen base to the trunk. The base is knotty and peppered with holes.  Kinda like a bad burl right at the ground line and extending up for 1 - 2 feet. Most researchers say this is caused by the chestnut blight fungus.

It's pretty much worthless here for sawtimber.  Medium worth for wildlife.  Good, of course, for firewood.

[WDH]

It is, as Swamp has pointed out, a very pretty oak in Fall color. 

[scgargoyle]

In Virginia, scarlet oak quite often has a swollen base to the trunk. The base is knotty and peppered with holes.  Kinda like a bad burl right at the ground line and extending up for 1 - 2 feet. Most researchers say this is caused by the chestnut blight fungus.

It's pretty much worthless here for sawtimber.  Medium worth for wildlife.  Good, of course, for firewood.

What makes it worthless- the swollen base? Or is scarlet oak just useless in general? I have quite a bit- I was thinking of trying to use some for flooring in my house- random width, rustic type stuff. I've noticed a number of smaller ones on my property with the swollen base, but the bigger ones (24"dbh) look normal.

[WDH]

SC,

Down our way it can make a pretty nice tree.  Scarlet does not self prune as well as many oaks, so it can be limby, especially on a poor site.  In your part of the country where it is well adapted, similar to the slope and elevation that Lanier Lurker is at, Scarlet can make some nice lumber.  I sawed one up over Thanksgiving and it had character . 

I say go for it!!

[scgargoyle]

Well, we'll know once we start opening 'em up. The trees have to go anyway to make room for the house. Mine have long straight trunks, and the branching is high up. I wouldn't mind a few knots for character.