Good question, spruceman. I don't have any answers (guess would be that genetics are a big part for trees that never provide much color). But, mostly weighing in on your second point about color on juvenile v. more mature trees.

I've seen the same thing in Chinese Pistache here. My guess was that the older trees have a more developed root system and so don't usually get the kind of water stress that seems to help some trees really put on a nice fall show. ?? I've read that cool dry autumns often produce the best color where irrigation isn't involve.

I've noticed the same thing about young trees, Spruce, in particular, post oak seedlings make beautiful red color, whereas the big ones only turn brown.
I picked up some oak leaves and made a picture of them -
{{gwi:493062}}
The big reddish brown leaf on the far left is a swamp chestnut oak - the one to the right and slightly above it is a bluff oak leaf, also reddish brown but more red. There's another bluff oak tree on my property that's still full of green leaves, so I assume it must have made new leaves again in the summer after the worms chewed most of the first set. The red and green leaf comes from a tree that I grew myself from an acorn I found under a swamp chestnut oak - 'looks like it'd make a good Christmas decoration!:) Most of the leaves are thin at the top and flare out at the bottom - people on this forum decided last year it must be a hybrid, most likely from q. michauxii and q. lyrata. It's my favorite tree, because it's grown faster than just about any oak I've ever grown - I think there's something to that hybrid vigor thing.
The next three leaves are post, red, and water oaks - they all came from big trees, and you can see for yourself how brown (and ugly) the leaves are.
Maybe good fall color is somehow tied in with cold winters, since the Deep South is so lacking in both long, cold winters and fall color. Or maybe it's something in the soil? I don't know - 'hope somebody else does!
Sherry

What about hybridization? Oaks can hybridize naturally and that could create oaks that have better color especially if they could get a bit of a red oak in them.

Sherry, love the red and green leaf! Cool.

It's not logical to label a character as genetic or environmental, as all characters reflect the interaction of environmental factors on particular genotypes. Even clone members are not identical in their phenotypes -- their appearance, growth rate, etc. For example, all Lombardy poplars are a clone, but if you look at a line of them planted up and down a slope from moist at the bottom to drier up above, they will turn color at different dates, drop leaves at different dates, grow at different rates, even have leaves of different average sizes. Etc.
Red fall coloration requires anthocyanin pigment. Cold fall weather, above freezing, with bright sunshine intensifies reds. But there must first be anthocyanin in the leaves, and synthesis of any compound requires first the genetically controlled predisposition to form the pigment. Depending on how the production of anthocyanin is inherited -- by major single gene action such as a dominant/recessive situation; or by multiple genes (quantitative gene action), or in some other way -- there will be genetic variation within the oak species as well as between species. But soil chemistry and climatic details are certainly capable of having an effect on how strongly the genetic characters are expressed. So the answer is yes!

It seems like the oak colors were especially good this year in parts of the South, b/c we had an extended cooler than normal fall. I think most areas of NC were 5-10 degrees below normal.

Pinetree:

I love your answer, "yes." That reminds me of the professor I accompanied to Mexico as a field assistant many, many years ago. He was collecting alpine plants from all the mountains in Mexico that had a timberline--what an experience for me. Anyway, I was the "hot" young botany student and always had these thoughtful questions that I would phrase as a question about two choices--"is it X or Y?" I would ask. My questions would take at least a couple of minutes to frame, and then when I was done, he would just say "yes." Because of my unbridled enthusiasm for asking questions, he got me with this answer repeatedly. I bet you are, or were, a professor also, and that you have fun with your students in a similar way.

But my professor never gave all the wonderful information you just gave us before you said "yes." He would just say "yes" and force me to reframe my question. Anyway, the way you ended your response brought back memories!

Sherry:

Yes the north has a reputation for the best color, but I wonder--there are so many exceptions. Some of the best color I have ever seen has been relatively far south (maybe far north from your perspective) in areas east of D.C. where there are wonderful red maple and sweetgum trees. And sometimes in the north the color can be a real bust--the best years are the years when we don't have freezing weather early. In the mountains of western MD in years when a freeze is delayed until unusually late, we get wonderful color in trees that are never thought of as producing good color, such as black cherry (red, orange and yellow), and even black locust (yellow).

Well, the bottom line for me with the white oaks is the question of whether it would make sense if I wanted good color to collect acorns from the best color producing trees. From what pinetree says that may help, but because there are so many other factors involved, it is a gamble (and probably a long shot) that the work involved will produce results to justify the effort. I guess I will enjoy white oak color where I find it, and leave it at that.

--Spruce

This discussion reminds me of something. A few weeks ago I passed by a beautiful red-leafed tree on the edge of a cow pasture. On the way back, I made it a point to look at the leaves to see what type tree it was, since color like that is so unusual for this area. I was shocked to see that it was a plain old sweetgum! The sweetgums in my woods don't make good color, but this one growing all by itself out in FULL sun was beautiful, so I assume a lot of sunlight can make a difference.
Like you said, there are many factors involved.
Sherry

Sherry:

I am surprised at what you say about your sweetgums there. If I were to name the trees with the best color in the areas where I have lived and/or have commonly seen fall color, I would rank sweetgum as my #1 color tree. A big reason for this is the reliability of the color, but maybe more important is the variety--color from a very dark purple/red, to dark red, to scarlet, to a glowing bright red, to orange, and finally to yellow, often all on the same tree. My other favorite color trees are red maple, sugar maple, blackgum, and finally, white ash. Of course there are others, and I know I am leaving out scarlet oak, but I have not seen that many large ones with really great color. And white oak, although sometimes spectacular, is not consistent enough to make my top 5 list.

A thought about oaks color and genetic determining factors--it may say something that there are not many oak strains/cultivars sold for their color. I am certainly not aware of any white oaks sold for their color. That suggests that genetic factors are not really reliable, except those included in the overall makeup of species. Perhaps most of the differences we see are soil and other site factors. Does anyone have any further thoughts about this?

--Spruce

Spruce, sweetgums do make fall color down here, but it's minimal, sort of a very dark purplish brown color that doesn't stand out. The sweetgum in the sun really jumped out at you, as brilliant as the nutall oak that Pam posted on the other thread. I can't remember exactly what shade of red it was, but I'm thinking it was true red.
Sherry

Genetics, soil conditions, and the weather are the 3 factors as I understand it. Last year collected shumard acorns only from trees with good red color, all in pots, some of the seedlings had good color and some were fantastic. Half of them have now been planted in the ground, hope the color continues as they get bigger.
This year I've collected Texas Red Oak acorns, only from trees with good color.
Don't believe that genetics guarantees good color, but believe it increases the odds.

Scotjute:

Interesting. Thanks.

One thing I have learned is that the genetics of trees is really complicated, and sometimes defies easy explanation. Not to go off my own topic here too much, here is a strange and frustrating example I found recently:

In general, the growth form of trees is clearly genetically controlled. There are various strains of trees that reliably produce specific characteristics, such as strong straight growth. The "Purdue" strain of black walnut is one example. Not long ago some people thought that a strain of black cherry could be selected for fast, straight, exceptional timber producing trees. Musser Forests, for a year or two offered seedlings from selected trees.

But now, it seems, that research has shown that these efforts all fail--that seed from selected trees is no more likely, at least as far as any casual observation can show, to produce superior trees than the seed collected from inferior trees!!

Now I can attest that the growth of black cherry trees is clearly genetically determined--that the growth of the straighter trees is not just the result of chance factors, such as insect attack, storms, or whatever. I know this because the trees that sprout from stumps of cut trees invariably grow just like the original tree--amazingly so. I have one very crooked tree that was cut, and the sprouts grew exactly the same, with exactly the same odd twist. Another I cut that was amazingly straight and tall, produced sprout offspring that were carbon copies--not just also straight and tall, but with the same exact branching pattern and form of the trunks.

But for some reason, the seed from black cherry trees shows no observable tendency to result in offspring that are anything like the parents. My guess, perhaps an obvious one, is that there many genes that control growth form in black cherry trees, and different variable factors may control their expression. Of course, the offspring of black charry trees are likely to have two parents, but even if this is the case, there should be some reflection of the one superior parent. I don't know how important cross pollination is in black cherry. Perhaps it is not needed, and if not, then it is even more remarkable that growth characteristics are not passed down to offspring.

Maybe color in oaks is just another example of the unpredictable way genes mix and operate when there are a number that work to control some aspect of growth. Maple cultivars for color are very, very common, but perhaps the genetic makeup of oaks, or most oaks, works in a much more complicated fashion, at least as far as color is concerned. I wonder, do oaks have a larger genome than maples?

But, in any case, scotjute, it is always worth a try to select for color in oaks--and they may not all be the same in regard to the transmission genetically of color tendencies. Maybe if I come across something special and have an oportunity to collect...

The older parks in the city I live in have many oaks. White, red, and swamp white. The whites do produce a good reddish fall color. In this regard, they are the best of the bunch. The red oaks do not exhibit much at all in the way of fall coloration, and this is even more true of the swamp whites.

For over ten years now, we have planted many "Autumn Blaze" maples on streets and in parks. My boss and I both noticed that this fall was their best coloration year so far. Not sure why. We had a long cool, but not super-cold fall, and somehow, this seems to have worked in favor of a good red coloration.

No answers here, of course. Just some random bits to throw into the conversation.

+oM

Spruce, I've been busted.

Pinetree:

I laughed so hard my wife just ran upstairs to see what was so funny.

--Spruce

Tom:

One thing I have learned recently planting trees at my new place just north of Winchester, is that some trees take a few years to express their color potential. A year or so ago in this forum, or perhaps in "Maples," I complained about my Burgundy Belle maple. For the first four years I had it, it just had its leaves frozen off in December. I said in the forum that it was obviously a tree that should not have been sold this far north--that it was a tree adapted for the south. And the name suggests southern origins. No color at all--just blackish green frozen leaves. I thought about getting rid of it, but I kept it because otherwise it was a pretty tree. Then last year, a week or two after the other maple cultivars I have, it turned and produced some mediocre color--good enough to be a plus. And now this year, again a little later than others, it produced color as good as any of my maple cultivars.

I also have an Autumn blaze--the color is not spectacular, but it has gotten better each year.

Here is something that suggests the importance of soil. My soil is of a type that I guess makes it difficult for roots to penetrate deeply very fast. When the soil gets a bit dry, it is like concrete. And we have had a lot of dry weather in recent years. So maybe what happens is here, at least some trees need time to get their roots down into the "B" soil horizon, which is, by the way more acidic than the "A" horizon soil, and that may influence the color.

Maturity of the trees may also have something to do with it. My white oaks still retain their dead leaves through the winter. This is common with young white oaks. As they get a bit older and larger they will drop their leaves in the fall. I don't know what this has to do with color exactly, but trees change as they get older and/or their roots go deeper.

--Spruce

misssherry! I love that green/red leaf!

Spruceman, I have a photo to share to illustrate the differences in individual trees growing side by side. These are two white oaks(the red is the same one I used in the photo I posted in the other topic about oaks). There is yet another mature white oak behind and a bit to the left of the red tree, that didn't do much either. The green one in this photo had only the slightest amount of red, and at peak color was mostly a muddy brown.

{{gwi:493064}}

Gaalan:

Very interesting picture--not just because ot the difference in color between these two trees, but for me there is something just a little strange, for an eastern white oak, about the color of the tree to the right with its green mixed with a kind of yellow brown or tan. That is something that strikes me as wrong for a white oak. I say "strikes me" because I cannot really be sure, but it seems like something I might see with a swamp white oak or some other of the "white oaks," and not Q. alba, which when it just turns a kind of brown still mixed with green, the brown is more a reddish brown. But I await others to comment on this--there is little confidence behind by speculation here.

In any case, my thought here is that white oak hybridizes with several different species of oaks naturally. Could this tree to the right be a hybrid? Could it look almost exactly like a white oak and still be a hybrid, involving a back cross to Q. alba, thus explaining the strange yellow element in the coloration?

But you say that a bit later, the tree to the right did have a reddish element in its color, which would point back to Q. alba, but not eliminate the possibility of a hybrid with something that would tend to turn a yellow brown.

Or could what I see that seems strange for a white oak be just a color bias in the picture?

I must admit I know nothing about oak hybrids, except that they are not unusual. This must be another complicaing factor for the question of oak tree fall color.

--Spruce

Spruceman...it could be a regional thing, but white oaks in Raleigh do the same thing. Some are brilliant and some are that yellow/green/brown mix. I don't think swamp white oak are very common in the RDU area either.

jqpublic and gaalan:

Well, I can accept that this is a regular white oak, but if I were in the woods in my area and looked off into the distance--too far away to see leaf shape, but just to see the color, I would guess the tree to the right to be regular chestnut oak.

If you have been following my comments about various kinds of trees in these forums for very long, you know how interested I am in the variations between individual trees of various species, most particularly, Norway spruce and red maple, but some others besides.

White oak is one of my top favorite trees, but I have never focused that much on individual tree variation, except to note some fair amount of variation in growth form and maybe also some in the bark. The foliage, from tree to tree usually looks very much the same to me--quite beautiful, but not much variation from tree to tree.

But the variation in autumn color is really amazing! Well, I find trees endlessly fascinating. And frustrating, because it is so hard to find answers to all my questions!!

Anyway, thanks for the info/pictures. These forums are really wonderful because we can share so much information, and share it from so many different parts of the country.

--Spruce

Spruceman, I can say for certain that both trees are eastern white oak. They both have the classic white oak leaf with rounded lobes and deep sinuses, which is beautiful! Isn't it amazing to witness such variation among individuals?! I was rummaging through some older photos and came across a picture of the same pair of oaks from last year. As you can see they were very similarly colored then. Thats another very interesting facet of fall color, whether the same plants turn the same colors every year. As I have observed, many do and many don't. Fascinating!

{{gwi:493066}}

11/28/07

Over here in North/Central Texas, the fall color of native red oak have been exceptional. The cool off started in mid- August and near freezing temperature came in October. We don't typically see that until mid-November so that ruined some of species for fall color but it sure was great for red oaks here.

Spruceman: Thanks for the insight!! I know around here some white oaks don't have the flaky peeling bark...and some do. It would be interesting to see if there is a correlation between the bark texture and autumn leaf color?!

jq:

Yes, I have found that variations in diferent characteristics can correlate--for example, with Norway spruce a special kind of very finely flaking reddish bark almost always corelates with a weeping habit of the branchlets. Not that the weeping branchlets don't occur on trees with another kind of bark, but with this special kind of reddish bark I usually see the weeping branchlets.

I have to admit, however, that my powers of observation, whatever they are, have not yet focused on any correlations with autumn color color. But it would not surprise me if there were some correlations. That would be good--we could look at the bark of some tree, or some other part of a tree, and then, never having seen it in the fall, make a prediction as to the color it would produce. I will be on the lookout for this kind of thing from now on.

--Spruce

This thread has been going long enough that I thought I'd break dormancy to make a comment. In CO we just had an above average fall for oak coloration. Swamp White Oak has become a common park & residential tree here over the past fifteen or twenty years because of its tolerance of drought but the fall color is usually a bust. This year a fair number of them--about half--had decent and long-lasting yellow, orange and even red foliage (not solid, but mixed on the leaves). There is a parkway row planting of five of them near my house that were very nice, but one was spectacular with a lot of strong red. These trees were all about the same size, probably coming from the same nursery and planted simultaneously and I assume the soil is uniform. If that one tree proves reliable for fall color, it ought to be propagated. Does the nursery industry propagate Q. bicolor mostly from seed? OK, back to sleep now.

Spruce,

In my experience, it's a combination of all three. And I've seen Q. montana (Q. prinus) in nearly pure stands in Eastern PA that turn a brilliant rusty yellow orange in the fall.

Spruce, et. al.

As many of you know, I am new to this area, am learning and have many questions.

Question: Is fall leaf color in seedlings fairly consistent as the tree matures?

This spring, I planted seedlings of Swamp chestnut oak (Q. michauxii), Nuttall oak (Q. nuttalli), Cherrybark oak (Q. falcata v. pagodafolia), and southern red oak (Q. falcata).

The SCO seedlings leafed out first, and turned first - the leaves were mostly orange, turning to tan-gold-buff. The cherrybark leaves are an intense wine red, the Nuttall leaves are a brilliant scarlet red. Today, the leaves on some red oaks are mainly or completely green. Despite a minor hurricane, a long nor-easter, and a drought this summer, leaves remain on all the seedlings, but are beginning to fall now.

I recall a discussion about leaf shape, that it can be difficult to ID a young oak because leaves on a seedling can vary in shape. I think the discussion involved acorns Sherry planted last fall. She collected acorns from many locations and was trying to ID the seedlings.

This led me to wonder if leaf color is similar to leaf shape - variable in seedlings, becoming more consistent with age, i.e., if Nutall oak seedlings are bright red now, as youngsters, is it reasonable to expect them to be bright red in adolescence or adulthood?

I know leaf color differs from year to year due to environmental factors. Last year, despite a drought, we had spectacular color. This year, the wind from the hurricane and nor'easter blew leaves off many trees and left others in shreds. Despite these factors, I'd rank fall color this year as B+ (in the leaves that remained).

Pam:

One special factor affecting the color of young seedlings may be the microclimate. Trees with leaves within a foot or so of the ground may have cooler nighttime temperatures, higher humidity, and warmer daytime temperatures.

Of course as little trees have their roots go deeper, they may get different nutrients and get into more acidic soil. And then maybe changes in the tree because of maturity may affect color.

As for the color you see as these trees mature--hard to predict. You will just have to wait. And then some trees that produce little or no color as seedlings may end up being your best color trees.

--Spruce

In the oak-hickory forests in SW Va and here in Md, the "white" and "red" oaks in the level mesic spots often didn't color much -- mostly browns. Trees in drier spots, especially sun-drenched, acidic SW-facing slopes, colored the best. So sunlight, low pH and maybe dryness seems to excentuate what we view as the "best" color. Another aspect is frost -- early frosts seem to cause more browns.

I have a 5' acorn-grown Chestnut oak sapling that had 2 growth spurts this yr. The older leaves on the first flush turned yellow-brown, but the younger 2nd flush ones stayed green later then turned a deep maroon. So even leaf age plays a part.