Grafting Korean Hornbeam to American Hornbeam?

[Poink88]

Is it possible or recommended to graft Korean Hornbeam (KH) to American Hornbeam (AH)?

I like KH and was sold an AH with huge leaves. I want to change all its foliage if possible. Should I or leave it be?

Thoughts (pro or con) welcome. Thank you.

 

[Leo in N E Illinois]

I took a grafting class years ago, at a commercial nursery, orientated toward landscape material, not bonsai focused. This nursery was grafting a select cultivar of Carpinus carolina onto seedling C. carolina. They emphasized that success rate is low unless heat and humidity were applied. Of course this was Wisconsin, where an average summer is often cooler than a Texas winter. Point being, summer grafts done late July or early August were put into a poly house and kept above 70 F, with mist applied every 15 minutes. This treatment gave them a good (better than 70%) take rate.

Without the constant 90+% humidity and heat, they said success of hornbeam grafts was less than 10%.

Apples needed no extra protection, no extra humidity or heat - they took, and even for my first time all my apple grafts took.

So judging by what I saw - yes hornbeam can be grafted, and no - I wouldn't recommend it unless you had a commercial grade set up for the after care.

 

[Poink88]

Thanks Leo! That is an awesome info!

 

[Leo in N E Illinois]

On a separate note, leaves of Carpinus caroliniana, American Hornbeam, and for that matter all the Carpinus, the leaves to reduce dramatically, with ramification. It should not be hard to get proportionate leaves once you have 2 or 3 levels of branching in your foliage. New leaves on young branches are big, but big leaves means healthy growth, on a young tree you want the big leaves. Only worry about smaller leaves once you are within a year or two of showing the tree.

 

[M. Frary]

The leaves of American hornbeam reduce right? I hope. And if they can be made smaller that's what I would do. Of course I've never grafted a thing and if that's something you're comfortable doing let it rip. They are pretty closely related trees so it should work. They graft pear limbs onto apple trees for goodness sake.

 

[GrimLore]

Is it possible or recommended to graft Korean Hornbeam (KH) to American Hornbeam (AH)?

I like KH and was sold an AH with huge leaves. I want to change all its foliage if possible. Should I or leave it be?

Thoughts (pro or con) welcome. Thank you.

They will reduce well down the road, I would guess you are pinching and encouraging a lot of branching and will be for two seasons. After that leaf reduction will be similar to an American Elm... trim, trim, and trim again.

Grimmy

 

[Poink88]

Thanks guys.

Another problem I didn't mention is that the AH seems to get leaf burn much easier than KH. Even though I keep it under some shade here. My KH under shade is very healthy and foliage is is all thick, dark green, and shiny.

I am not pinching it yet since the branches are really scrawny and the leaves look weak.

Good to know the leaves reduce though.

 

[Martin Sweeney]

Dario,

I have used thread grafting of American Hornbeam on American Hornbeam successfully in the past. I have never tried Korean onto American.

Arthur Joura uses lots of American Hornbeam at the Staples Collection at the NC Arboretum. He says if you place them in full sun (understanding that Asheville is not Austin) in the spring before bud break and keep them there as long as the plant is healthy, then give them as much sun as you can, that the leaves will reduce significantly. I have seen Arthur achieve American Hornbeam leaves reduced to less than 1/2 the normal size in the NC Arboretum collection using this method. Sorry, no pictures and no personal experience.

I think it is worth trying, although since American Hornbeam buds back so well even from the trunk, you may have trouble getting Korean to stay permanently,

Regards,
Martin

 

[Poink88]

Thanks Martin.

I will see if the leaf burning issue resolves before trying grafting since leaf size should reduce later.

Thanks guys!

 

[amkhalid]

I am new to AH but defoliated my forest this year for the first time. I am amazed by the results, the new leaves are half the size and smaller than my (not defoliated) KH leaves.

Pics here if you are interested
http://lakeshorebonsai.com/?p=2134