Scrub Oak Experiments

[ShadyStump]

There's a dirt bike/hiking trail just a little ways outside of town, and last summer while hiking out there I discovered an area where the native scrub oak we have here was growing tiny leaves with sharp pointed lobes.

I've been told that this sometimes happens when the trees are growing in drought conditions, but I'd never seen it before in all my years in the woods. Then, while reading up on Gambel's oak - which I had come believe these and others like them were - I learned that that species routinely hybridizes with other scrub oak varieties, and those varieties hybridize with each other so prolifically that botanists are at a loss for how to even classify them.
I've concluded that most of trees in question in my region are not true Gamble's oak, and not very likely hybrids of it, but are these other random hybrid scrub oak, so that's how I'm going to refer to them.

Then I had the thought that if these are unclassified hybrids, and since I only saw the thorn lobed trait in certain thickets in a certain place but not in neighboring thickets, then perhaps this is a trait peculiar to that particular hybrid. So I took my trusty trail mutt up that trail again, and sure enough saw the same leaf traits in the same area, just like last year. Hoping to find out for sure the nature of this trait, I went prepared to take a few cuttings...

 

[ShadyStump]

My current hypothesis is that it is indeed a genetic trait of the tree/shrub/however you want to consider this habit, but seeing as how it has been on the dry side this season it may be triggered by climate conditions when the tree begins to leaf out in spring. This is corroborated by finding a bit of large round lobe in the remains of an insect chewed leaf on one of my cuttings. I forgot to get a pic of that.

This is the best pic I got, but other leaves are much sharper, comparable to many ilex. The objective is to find out if the leaf size and pointed ends are due to conditions, or if under more nominal conditions the trait proves transient.

I took several softwood and semi-hardwood cuttings, dipped the ends in rooting powder, and stuck them in a tray of SafeTSorb mixed with peat and coco coir, and placed them in my mini greenhouse/humidity tent. The greenhouse gets broken shade most of the day, a couple hours of full sun, then indirect sun to full shade as the day progresses. In this position, the temperature rarely reaches 90F even when it's hotter outside, but the relative humidity climbs to 80% which could be problematic for a species used to 10%.

I also took 3 cuttings - 1 softwood, 2 semi-hardwood - from another scrub oak with rounded lobed leaves, though very small, as a control.

The whole shebang after sticking, and trimming the leaves. The controls on the rounded side of the tray.

Oh, hey, there's that big round leaf, front and center.

My intent is for this to be an evolving experiment over time, seeing how new foliage develops, what traits they have, and maybe what triggers them.
My luck with cuttings has been hit and miss, so first thing is to see if we can even get this thing off the ground.

 

[ShadyStump]

My trusty old trail mutt, Dilly, for them what cares, recuperating from the adventure.

 

[Potawatomi13]

Leaves look much like one CA oak. As you likely know Oak have poor chances of rooting. Might have helped a small amount to have much shorter stems. If available maybe could collect acorns, seedlings under trees in question

 

[rockm]

All oaks are extremely promiscuous. They interbreed easily. My Texas live oak is loaded with little acorns this summer. I don't know what fertilized them, but it's technically a white oak species and there are plenty of White Oak (quercus alba) and others in the woods. I get acorns most every year, but most grow to the size of a BB or a bit smaller then drop off the tree before they're fully developed. Some have stayed and matured only to be spirited off to the woods by squirrels, so I haven't had a chance to actually grow one out.

 

[ShadyStump]

Leaves look much like one CA oak. As you likely know Oak have poor chances of rooting. Might have helped a small amount to have much shorter stems. If available maybe could collect acorns, seedlings under trees in question

These scrub oak and the true Gambel's oak propagate in stands and thickets mostly from root suckers, so I'm hoping that means they root easier than the more standard oak tree species.
Like @rockm just pointed out, as promiscuous as these can be propagating from acorns is not likely to yield the traits in question.

 

[GGB]

I’ve been day dreaming about collecting scrub oak for a long time. I have only come across them on protected land so far. I’m talking about Quercus ilicifolia (in case commons names over lap) also called bear oak. Sounds the same though. They grow on really dry mountainous sites and have 1-3” leaves that turn beautiful red in fall. Incredible snaking habit and very small. It’s the only native oak here with small leaves. Photos below of one I was petting this past fall.

 

[ShadyStump]

I’ve been day dreaming about collecting scrub oak for a long time. I have only come across them on protected land so far. I’m talking about Quercus ilicifolia (in case commons names over lap) also called bear oak. Sounds the same though. They grow on really dry mountainous sites and have 1-3” leaves that turn beautiful red in fall. Incredible snaking habit and very small. It’s the only native oak here with small leaves. Photos below of one I was petting this past fall.View attachment 445766

They do seem to be very similar.
I've been on the hunt for a good one the past year or so, but, like most trees here, the local mountain geology makes collecting difficult. You're trying to separate the roots from rock.
That's why I'm hoping for some success with these experiments. If I can propagate them from cuttings, AND preserve some unique characteristics, the doors fly wide open for anyone who wants to try one.

 

[nuttiest]

If you collect seedlings, thy are attached to an acorn if you REALLY want to get close on parent tree closeby

 

[ShadyStump]

If you collect seedlings, thy are attached to an acorn if you REALLY want to get close on parent tree closeby

I might try that come end of summer or next spring. I'd really have to wait and make sure the leaves look the same if I want to get the same traits.

I might go back and make an attempt at some toot cuttings, but I've never tried them before. Need to research it.

 

[Potawatomi13]

I’ve been day dreaming about collecting scrub oak for a long time. I have only come across them on protected land so far. I’m talking about Quercus ilicifolia (in case commons names over lap) also called bear oak. Sounds the same though. They grow on really dry mountainous sites and have 1-3” leaves that turn beautiful red in fall. Incredible snaking habit and very small. It’s the only native oak here with small leaves. Photos below of one I was petting this past fall.View attachment 445766

Absolutely LOVE shape of Bear Oak leaves.

 

[GGB]

Absolutely LOVE shape of Bear Oak leaves.

Yeah, sort of a simplified version of the classic oak leaf shape. Or at the very least unique

 

[ShadyStump]

As anticipated by many, not very much looking alive at this point.

There's one of the small round lobes still green on the right there, and one of the holly leafs still has some green at the base of the leaves, center left.

I'm still going to leave them all for a while, just in case, but looks like I'll be making another trip up that mountainside soon.

 

[ShadyStump]

Not had opportunity to get up that trail again this year, and with the leaves dropping I'm not certain if I could identify the stands I'm interested in.
That said, I'm hoping to get out that way for some hardwood cuttings if I can ID them, but I'd also like to try root cuttings. Unfortunately, I'm having trouble locating reliable information on best practices for root cuttings.

If anyone can point me to some decent resources, I'd really appreciate it.

 

[Crazy Diamond]

All Oaks are a pain to root from cuttings very few people have had success with them and usually only professional growers can root them

"Oak stem cutting propagation protocols typically involve softwood and semi-hardwood stem cuttings collected from juvenile stock plants (with various stock plant manipulations), treated with indole butyric acid (IBA) basal dips. Early research demonstrated that it is very difficult to root cuttings of Oak, particularly if they are taken from mature trees; and that rooting ability declines quickly after about 3 years of age. However, some progress has been reported in the period 1985-2014 using cuttings from both stock hedges and young plants; with two papers (Spethmann 1986 and Spethmann and Harms 1993) claiming that this can be done commercially. There was a small and shortlived Forest Research programme at Alice Holt involving propagating oaks by cuttings taken from coppice shoots (Harmer and Baker 1991, Harmer 2010). Drew and Dirr (1989) used cuttings from 3 year old stock plants of Q. robur and showed that this species gave the second highest rooting percentages (30-67%) of the 10 Quercus species tested. The authors concluded that propagation by cuttings is feasible for some species, including Q. robur, but not for others"

 

[ShadyStump]

Thanks for the info.
Still haven't found anything on root cuttings, but from your info there, seems I might have a chance if I can locate the youngest shoots in the thicket, but hardwood cuttings might be the worst idea.

 

[Colorado]

Thanks for the info.
Still haven't found anything on root cuttings, but from your info there, seems I might have a chance if I can locate the youngest shoots in the thicket, but hardwood cuttings might be the worst idea.

Shady, might it be easiest to just collect acorns and grow from seed? Of course you may not get the same exact DNA as the parent, but I’d think it would be “close enough” and much higher rate of success. Just some food for thought.

 

[ShadyStump]

I've considered this, but concluded the same thing so dropped it.
Come spring I'm considering digging seedlings if I find any with right traits, but that would require waiting until they leaf out, and thus digging them later than would be ideal. It also involves the issue of identifying seedlings vs suckers, but I'm not opposed to that as long as I can keep it alive.

 

[Crazy Diamond]

The article about oak propagation: https://www.futuretrees.org/wp-cont...egetative-Propagation-in-Oak-Worrell-2016.pdf

 

[Potawatomi13]

I've considered this, but concluded the same thing so dropped it.
Come spring I'm considering digging seedlings if I find any with right traits, but that would require waiting until they leaf out, and thus digging them later than would be ideal. It also involves the issue of identifying seedlings vs suckers, but I'm not opposed to that as long as I can keep it alive.

Very early in Bonsai "career" dug young trees after leaf out many times. If getting good roots and give good aftercare survival almost assured. Also potting soil was just poor garden dirt but worked.