Scrub Oak Experiments

[ShadyStump]

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.

Getting those roots is the trick around here. The mountain geology makes any digging not involving jackhammers and dynamite a bit sketchy.

Does anyone have any advice on best time for collecting root cuttings? I've not tried before, but it seems this might be my best bet.

 

[ShadyStump]

Not the best time of year probably, but I went up and collected a couple root cuttings today. Hard to tell exactly what trees I'm looking for this time of year, but I know I found a couple of the right ones.

Never done root cuttings before, so fingers crossed.

 

[El Tigre de Bonsai]

i have a bunch of failed oak cutting and root layering attempts. I have collected acorns from several species and not all of them have died so far.

 

[El Tigre de Bonsai]

i would be surprised if any of those cuttings make it. they are so incredibly sensitive, especially during the more dormant months. I found an acorn today that is fertile, you might be able to do the same if you look on the ground where a tree fruited a bunch this year.

 

[Leo in N E Illinois]

Not the best time of year probably, but I went up and collected a couple root cuttings today. Hard to tell exactly what trees I'm looking for this time of year, but I know I found a couple of the right ones.

Never done root cuttings before, so fingers crossed.y

Root cuttings are different than trying to root twig or branch cuttings. It will be interesting to see if your success is better than before. Plant those root segments with just a short bit of stem above the media. Sun will help the tissue of the end convert to making stems and leaves. I'm rootin' for ya.

But seriously, get some acorns going. Oaks are relatively easy from seed. They do need stratification, but usually just 12 weeks of cold moist stratification is enough. None of the complicated double dormancy that some hornbeams and maples can do. Start a lot of seedlings, a flat of a couple hundred, so you can select the leaf characteristics you are looking for.

And, when thinking about oaks, what to we think of? FAT TRUNKS. Forget them scrub oaks, you don't get FAT TRUNKS there. Look into your local red oaks, or white oaks. I've been playing with BUR OAK, Quercus macrocarpa. Bur oak is hardy into zone 3, so most of USA at most elevations it can be grown without protection. The down side of Bur Oak is that young trees have HUGE leaves, but once you get 3 degrees of branching, meaning you trunk, then branch, then branch., then twig then leaf, I have had a few leaves less than one inch long. Admittedly, same plant on a less ramified branch had a 8 inch leaf. But as you get your branching developed, and get the structure of your twigging set, bur oak leaves should come down in size nicely.

Another reason to grow bur oak, the bark is the most coarse of all the northern oaks. If you want craggy, fissured bark, bur oak is the go to oak. Runner up would be northern white oak, Quercus alba. Only better bark is the damn near impossible to grow in the north Quercus suber, the cork oak, The cork oak is Mediterranean, meaning that it must have a mild winter. In my experience even a frost can kill them, here in Chicago if it drops below freezing long enough for the pot to freeze the roots, the cork oak is dead.

So try the local race of Bur oak that I am sure is somewhere in your area of Colorado. It will trunk up nicely, much better than a scrub oak, and it is incredibly cold tolerant. And has great bark too. Big leaves will disappear once you have enough levels of branching. Worst case you can resort to defoliating just after the summer solstice in the year you are going to display it.

 

[ShadyStump]

Root cuttings are different than trying to root twig or branch cuttings. It will be interesting to see if your success is better than before. Plant those root segments with just a short bit of stem above the media. Sun will help the tissue of the end convert to making stems and leaves. I'm rootin' for ya.

But seriously, get some acorns going. Oaks are relatively easy from seed. They do need stratification, but usually just 12 weeks of cold moist stratification is enough. None of the complicated double dormancy that some hornbeams and maples can do. Start a lot of seedlings, a flat of a couple hundred, so you can select the leaf characteristics you are looking for.

And, when thinking about oaks, what to we think of? FAT TRUNKS. Forget them scrub oaks, you don't get FAT TRUNKS there. Look into your local red oaks, or white oaks. I've been playing with BUR OAK, Quercus macrocarpa. Bur oak is hardy into zone 3, so most of USA at most elevations it can be grown without protection. The down side of Bur Oak is that young trees have HUGE leaves, but once you get 3 degrees of branching, meaning you trunk, then branch, then branch., then twig then leaf, I have had a few leaves less than one inch long. Admittedly, same plant on a less ramified branch had a 8 inch leaf. But as you get your branching developed, and get the structure of your twigging set, bur oak leaves should come down in size nicely.

Another reason to grow bur oak, the bark is the most coarse of all the northern oaks. If you want craggy, fissured bark, bur oak is the go to oak. Runner up would be northern white oak, Quercus alba. Only better bark is the damn near impossible to grow in the north Quercus suber, the cork oak, The cork oak is Mediterranean, meaning that it must have a mild winter. In my experience even a frost can kill them, here in Chicago if it drops below freezing long enough for the pot to freeze the roots, the cork oak is dead.

So try the local race of Bur oak that I am sure is somewhere in your area of Colorado. It will trunk up nicely, much better than a scrub oak, and it is incredibly cold tolerant. And has great bark too. Big leaves will disappear once you have enough levels of branching. Worst case you can resort to defoliating just after the summer solstice in the year you are going to display it.

Acorns aren't out of the question, but I'd like to make an honest run at the clones first.
Never done root cuttings before, and a search was mostly useless. Search 'root cuttings' and all you get is how to root stem cuttings. Don't suppose you know a decent resource off hand?

I do disagree on the fat trunk comment. We are talking bonsai, so "fat" is relative to size, and I routinely see these get 4 inch trunks without getting particularly tall. There's also the notion of the actual scrub oak clump planting, which in my region is what I think of.

One way or another, if I can get oaks with tiny leaves going, someone out there will be happy.

 

[LittleDingus]

Coming from the midwest not terribly far from @Leo in N E Illinois I can understand the burr oak and grow from acorn thing...but I think mountain scrub oak have some interesting characteristics.

I'm talking mostly from my personal experience with gambel oak from acorn and some trees I stared at long enough to bore my wife

They don't grow tap roots the way many oak do. Rocky soils are hard to develop thick tap roots in. Much easier to develop long root cords that can find moisture in rocky fissures.

They can and do grow colonies. I suspect that bodes well for root cuttings. The Colorado State University has a writeup here:

https://extension.colostate.edu/docs/pubs/natres/06311.pdf

that article states vegetative propagation (root suckers) is more common than from seed. That makes sense in the more arid regions they grow where food is more scarce. Our midwestern squirrel population does a better job at sowing new oak trees than an army of grad students ever will But, here food is plentiful and winter storage feasible. Try burying an acorn in rock...or digging it up from under feet of snow...I doubt many acorns survive long enough to be planted.

I'm very interested in how root cuttings turn out as my hope for the future development of my gambel oak is that it root suckers to fill in a thicket.

The bark does get quite rough judging by the ones I've seen in the wild...and at small diameters. I do wonder, however, if that's more the harsh environment than age. I suspect a lot of rough bark formation is more environmental than age in general. Even my young dawn redwoods that remain outside in the cold and wind develop rougher bark sooner than the ones babied in the garage.

I do think they are like most oaks and are a decades and not a years project unless you can manage to collect one...

 

[ShadyStump]

Coming from the midwest not terribly far from @Leo in N E Illinois I can understand the burr oak and grow from acorn thing...but I think mountain scrub oak have some interesting characteristics.

I'm talking mostly from my personal experience with gambel oak from acorn and some trees I stared at long enough to bore my wife

They don't grow tap roots the way many oak do. Rocky soils are hard to develop thick tap roots in. Much easier to develop long root cords that can find moisture in rocky fissures.

They can and do grow colonies. I suspect that bodes well for root cuttings. The Colorado State University has a writeup here:

https://extension.colostate.edu/docs/pubs/natres/06311.pdf

that article states vegetative propagation (root suckers) is more common than from seed. That makes sense in the more arid regions they grow where food is more scarce. Our midwestern squirrel population does a better job at sowing new oak trees than an army of grad students ever will But, here food is plentiful and winter storage feasible. Try burying an acorn in rock...or digging it up from under feet of snow...I doubt many acorns survive long enough to be planted.

I'm very interested in how root cuttings turn out as my hope for the future development of my gambel oak is that it root suckers to fill in a thicket.

The bark does get quite rough judging by the ones I've seen in the wild...and at small diameters. I do wonder, however, if that's more the harsh environment than age. I suspect a lot of rough bark formation is more environmental than age in general. Even my young dawn redwoods that remain outside in the cold and wind develop rougher bark sooner than the ones babied in the garage.

I do think they are like most oaks and are a decades and not a years project unless you can manage to collect one...

They do grow quite a bit faster and have much less dense wood than other oaks. Great for smoking meat, but even if you could cut lumber from it it wouldn't be terribly strong.

I think you're right about the bark.
In harsh times they grow slow, but get rough bark. When it's wet they grow like weeds, at least relatively speaking.

I have allot of suspicions about how these would do as bonsai, but little to back them up with so far. I'm going to keep try to research root cuttings since I'm sure I didn't do it right, and give it another go near bud break.

 

[Leo in N E Illinois]

@ShadyStump - root cuttings are actually quite easy, nothing really complicated.

#1 - grab a section of root, one end should have some branching and some feeder roots. It does not need a lot of feeders, but a little is helpful. Other end is the closer to the trunk end of the root.

#2 - cut the trunk end of the root clean and flat. If root is over 1 inch diameter, apply cut paste, generally cut paste is not needed.

#3 - bury the far end of the root. In clean potting or bonsai media. I tend to use bonsai media. Water well. Set on bench in very bright shade or half sun. I don't do anything extra. You could add humidity tent, but I'm in the Midwest, outside we seldom get below 70% humidity.

No hormones, Nada needed. In fact the use of hormones could inhibit if dose is not exact.

Vegetative buds usually form within a month or two, in spring and summer, anytime from a month to a year if root cuttings were struck in late summer, autumn or winter. For me the percentage of success is only 50% , but especially if you use twisted roots to create a gnarled segment of trunk, the result is awesome.

I have done flowering quince, Chaenomeles, elm and blueberry. In theory it could work on most species.

 

[ShadyStump]

@ShadyStump - root cuttings are actually quite easy, nothing really complicated.

#1 - grab a section of root, one end should have some branching and some feeder roots. It does not need a lot of feeders, but a little is helpful. Other end is the closer to the trunk end of the root.

#2 - cut the trunk end of the root clean and flat. If root is over 1 inch diameter, apply cut paste, generally cut paste is not needed.

#3 - bury the far end of the root. In clean potting or bonsai media. I tend to use bonsai media. Water well. Set on bench in very bright shade or half sun. I don't do anything extra. You could add humidity tent, but I'm in the Midwest, outside we seldom get below 70% humidity.

No hormones, Nada needed. In fact the use of hormones could inhibit if dose is not exact.

Vegetative buds usually form within a month or two, in spring and summer, anytime from a month to a year if root cuttings were struck in late summer, autumn or winter. For me the percentage of success is only 50% , but especially if you use twisted roots to create a gnarled segment of trunk, the result is awesome.

I have done flowering quince, Chaenomeles, elm and blueberry. In theory it could work on most species.

Thanks! I wasn't far off then.
I just lost track of which ends we're which, so buried them all shallow. They're on a heat mat as well. Can't see how it'd hurt.

 

[Captkingdom]

Shady, you should read this article about similar hybrids in Utah which I have been studying. Https://www.unps.org/index.html?hybridoak/hybridoak.html
The turbinella is most hollylike and it's evergreen. I have found a cross between turbinella and gambelli across the street from my house recently and it looks nearly identical to the pictures you shared. It is also evergreen though the leaves have browned a bit this winter.

I am planning to to to air later some of each this year and will keep you posted.

 

[ShadyStump]

Shady, you should read this article about similar hybrids in Utah which I have been studying. Https://www.unps.org/index.html?hybridoak/hybridoak.html
The turbinella is most hollylike and it's evergreen. I have found a cross between turbinella and gambelli across the street from my house recently and it looks nearly identical to the pictures you shared. It is also evergreen though the leaves have browned a bit this winter.

I am planning to to to air later some of each this year and will keep you posted.

Thanks for pointing it out. The ones I found certainly aren't evergreen, and very certain that seasonal environmental factors contribute to the leaf size and shape as if found large round-lobed leaves on the same plant. Still, it's worthwhile to experiment with propagating them, and determining the factors to reproduce to get the small holly-like leaves shouldn't be hard.

Still, knowing that this isn't an isolated phenomenon means that I can try from acorns, and still have a good shot of producing the results I'm hoping for.

 

[ShadyStump]

Up that same trail today, just in time to see them leafing out good and proper.
On a whim I grabbed this.

You think I got enough root?
Late in the season, I know, but this year my knees have caught up to my age. Heading up that mountain isn't the convenience it used to be. If I'm to continue this, I'll need something a bit more readily available. Here's hoping it takes and stays healthy.

Keep in mind that it has been WET this spring. Wetter than it's been in almost 20 years. So wet I barely water my trees.
The foliage still looks like this though.

This, and others in the area like it prove that there's a strong, maybe even primarily genetic component to this leaf type that would make it very easy to trigger if it doesn't happen on it's own.

I potted it up in mostly coco coir with zeolite and DE, gently coiling the root around the pot.

This one isn't necessarily for bonsai. I'm hoping to get it we'll established this year, and with any luck that big root will send off suckers as these trees are known to do. I'll then have the option of harvesting essentially new trees, complete with root.

 

[El Tigre de Bonsai]

did this survive? an impressive amount of work to get that much root out, but Oaks are so sensitive i wonder how this worked out

 

[ShadyStump]

Not looking too hopeful. I'll keep watering until it turns brittle.

 

[Loamstranger]

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

I’ve planted a bear oak from 3 gallon nursery container in the landscape and seeing as it back buds heavily it would be interesting to see it bonsai.

 

[ShadyStump]

I forgot about this project. I wasn't planning on doing any collecting this spring, but I really do need to keep this one going.

I have over the past year come across trees with similar leaves in completely different areas, and surrounded by the same species having larger, rounder leaves. On some trees I've seen both styles of leaf on different branches.

So I'm presently led to believe that there is a strong genetic component as I first suspected, but also that there is an environmental factor that triggers the small holly-like leaves.
It been wet enough so far this spring that I may be able to confirm whether it's a dry/hot response. We'll have to see if the gentle weather holds out.