Grafting 101

[M. Frary]

This thread is awesome!
I planned on trying some grafting this year. Mainly on Jack pines.
Isn't approach or side grafting what I should use or try scion grafting?
Either way,now I don't need to look it up all over the place. I just need to look here.
Thank you Scott for doing all of this. You don't know how valuable this knowledge will be in the future to me.

 

[markyscott]

This thread is awesome!
I planned on trying some grafting this year. Mainly on Jack pines.
Isn't approach or side grafting what I should use or try scion grafting?
Either way,now I don't need to look it up all over the place. I just need to look here.
Thank you Scott for doing all of this. You don't know how valuable this knowledge will be in the future to me.

You are welcome. I'm glad that you got something out of it.

You can either approach graft or graft a scion using the side cleft graft we talked about earlier. I'll talk about approach grafting next, but here are the trade offs.

1. Approach grafting is more reliable
2. Side cleft grafting is less visible when it's complete. A successful side cleft graft is almost invisible after a few seasons whereas an approach graft often leaves some visible swelling
3. Approach grafting is generally done to graft small shoots to larger branches. When the the branches are closer to the same size it's not as useful
4. Side cleft grafting doesn't require a long shoot that you need to bend into location - it just requires a small scion. So you don't have to grow it out for several seasons before you graft.
5. You have much more flexibility in where you put the graft with side cleft grafting. With approach grafting, you need to have some open space to make the cut and place the branch. With cleft grafting you can put the scion in some pretty tight places and position them really close to the trunk.

 

[M. Frary]

Side cleft grafting doesn't require a long shoot that you need to bend into location

Couldn't I just bend a branch over from a sapling sitting next to the tree I want to graft?
I plan on collecting some just to get my grafting skills up before I start in on a tree I want to keep.

 

[markyscott]

Couldn't I just bend a branch over from a sapling sitting next to the tree I want to graft?
I plan on collecting some just to get my grafting skills up before I start in on a tree I want to keep.

Hi Mike. Yes, and it might be just fine. Be aware though, if you graft one tree to another you can end up with differences in leaf (or needle) shape and texture. Their fall colors can be different and different branches can break dormancy in spring at different times. If possible, it's a good idea to take scions from the same tree that you're grafting.

 

[CWTurner]

Nicely done Markyscott!
It may not matter, but a bit like this:

often called a Brad Point bit, will not wander, making the hole cleaner. And notice that the outside edges of the bit cut before the main body of the bit, so the hole dimension is more accurately established.
Also, if you watch the exit side of the tree for when the point just begins to emerge, you can then finish the hole by orienting the bit in from the exit side for a nice clean hole.
CW

 

[aml1014]

This thread is motivating me to practice grafting, which I do think is an essential tool in this art.
I'm wondering if you think Acer Palmatum will graft on to Acer saccharinum (silver maple) rootstock? Silver maples do so well here and are such fast growers that maybe it'd be possible to graft Acer Palmatum branches onto a silver maple trunk that I've developed (since they can put on thickness quick and can develop a nice nebari quick) and possibly recieve more vigour from the Acer Palmatum branches.

Aaron

 

[0soyoung]

We discussed this in another thread a little over a month ago:

the different species of Acer are divided into sections, and each section into series. Grafting only works between species belonging to the same series

https://en.wikipedia.org/wiki/List_of_Acer_species#Section_Palmata

 

[markyscott]

Nicely done Markyscott!
It may not matter, but a bit like this:
View attachment 135021
often called a Brad Point bit, will not wander, making the hole cleaner. And notice that the outside edges of the bit cut before the main body of the bit, so the hole dimension is more accurately established.
Also, if you watch the exit side of the tree for when the point just begins to emerge, you can then finish the hole by orienting the bit in from the exit side for a nice clean hole.
CW

Thanks CW for the tip. And for another reason to go tool shopping! I definitely give those a try. They look great.

Scott

 

[aml1014]

We discussed this in another thread a little over a month ago:

https://en.wikipedia.org/wiki/List_of_Acer_species#Section_Palmata

So no go eh? Bummer

Aaron

 

[sorce]

So....

Besides "cheating", which I personally like to avoid, if just for the raised difficulty....

I've always been worried that a graft will be "weaker", in that it is only held by, whatever it is held by!, and not heartwood.

Is this so?

I always fear that at some point I will rip it off trying to wire it or something.

How bout some notes on that so I can have less fear and make a good tree!

Thanks!

I wanna do my ficus, threaded.

Sorce

 

[Dav4]

Great thread, Scott. Grafting is a fantastic tool for improving stock. This is a prostrata Juniper that I approached grafted shimpaku foliage on to a few years ago. The grafted foliage is much smaller and tighter then the original foliage.

You should know that this thread has inspired me to try scion grafting on a very old RMJ that has a habit of spitting out approach grafts on a regular basis! Fingers crossed!

 

[markyscott]

Great thread, Scott. Grafting is a fantastic tool for improving stock. This is a prostrata Juniper that I approached grafted shimpaku foliage on to a few years ago. The grafted foliage is much smaller and tighter then the original foliage.

You should know that this thread has inspired me to try scion grafting on a very old RMJ that has a habit of spitting out approach grafts on a regular basis! Fingers crossed!

Nice job on the grafting on that prostrata- it looks great.

Scott

 

[markyscott]

So....

Besides "cheating", which I personally like to avoid, if just for the raised difficulty....

I've always been worried that a graft will be "weaker", in that it is only held by, whatever it is held by!, and not heartwood.

Is this so?

I always fear that at some point I will rip it off trying to wire it or something.

How bout some notes on that so I can have less fear and make a good tree!

Thanks!

I wanna do my ficus, threaded.

Sorce

Hi Source. FWIW, I don't consider grafting cheating. It's a technique that's employed fairly regularly by pretty much everyone who is skilled at this and is sometimes the only option for improving your tree. Done well, I've seen it result in great trees from otherwise mediocre material. At this point, a fairly large percentage of trees in my yard have been grafted in one way or another. Several more than once.

Thread grafting results in a very strong graft union, right from the get go. It's a judgement call based on how fast the grafted branch is growing, but I've wired some of mine the same season I performed the graft. You have to be a bit more careful at the start with cleft and approach grafting, but they're generally strong enough to wire after a couple seasons.

 

[sorce]

Thanks Scoutt!

Sorce

 

[justBonsai]

But where's that approach grafting post!

This is the tree I intend to do approach grafting on. Mainly just the apex and the front stub. Everything else has usable buds for branch development.

 

[markyscott]

But where's that approach grafting post!

This is the tree I intend to do approach grafting on. Mainly just the apex and the front stub. Everything else has usable buds for branch development.
View attachment 135489

LOL! I'll get to it I promise. I'm just a poor working stiff with a bonsai addiction, but I promise that's next on my list.

Coast live oak? I've done approach grafts on southern live oak before and they graft pretty readily, even on the trunk. I'll make sure to talk about that and show some pictures. On yours it looks the long shoots are this year's spring growth? If so, we've got time - you'll want to let those harden off a bit before you start messing with them. When they're strong enough, just wire them into position.

 

[justBonsai]

LOL! I'll get to it I promise. I'm just a poor working stiff with a bonsai addiction, but I promise that's next on my list.

Coast live oak? I've done approach grafts on southern live oak before and they graft pretty readily, even on the trunk. I'll make sure to talk about that and show some pictures. On yours it looks the long shoots are this year's spring growth? If so, we've got time - you'll want to let those harden off a bit before you start messing with them. When they're strong enough, just wire them into position.

Yep, Coast live oak. That's all spring growth on there.

 

[markyscott]

OK. Mr. Bleu nudged me into. Let's tackle approach grafting next. Broadly speaking, approach grafting involves a shoot and an understock, both supported by their own roots. The cambium of the shoot and understock is exposed and the two are bound together. Over time, if the shoot and understock are compatible, they will graft and the shoot can be detached from it's supporting root system. Together with the detached scion or cleft graft and the thread graft we've already discussed, these three are the only grafts I've ever done. That said, there are many special use cases for each - grafting roots, grafting onto a thick trunk, etc. But everything I've ever done. Is one of these three grafts in various application.

So we undertand from our discussion that cleft grafts with detached scions are primarily used for junipers and pines whereas thread grafts are used mainly for broadleaf trees. The main advantages of an approach graft is that it has a higher success rate than cleft grafting and because the foliage doesn't have to be removed. That means we can use it not only for broadleaf trees, but pines and junipers as well. We can also use it for broadleaf trees such as Ficus Benjimina or boxwood that don't take very well to defoliation and thus may not respond well to thread grafting which requires that we remove all the leaves. It is also possible to graft fairly large branches in this way - certainly branches large enough to make thread grafting impractical. It is one of the most versatile of grafts and thus very important to master.

The primary disadvantage with approach grafting is the scarring. In thread grafting there is a simple entry and exit wound so that when the graft is severed there's only a small hole to callous over. With approach grafting,on the other hand, a strip of bark is removed in order for the scion to be attached. This can create callousing that can look unnatural, especially if the graft is done improperly. If all goes wrong and the graft fails, you only have two small holes to heal over with a thread graft. With an approach graft you are left with a nasty visible scar that can take years to heal. The damage may be permanent.

 

[markyscott]

So that's the why, what about the when? One major use case for approach grafting is when long shoots are grown on a tree and the shoots are grafted to other locations on the tree. This is very reminiscent of the thread grafting use case we discussed. And as with that example, the decision to approach graft is made the season BEFORE you are actually going to carry out the graft. You have to grow long shoots. And as the shoots are hardening off in late summer, the shoots are wired into position. You then leave them wired that way over the winter and carry out the graft in early spring the following growing season. That way you have the entire growing season for the graft to be complete - this will result in the highest success rate. So this is an important lesson - graft during the season of active growth.

By the time winter rolls around your tree should look like this:


See? The shoot has been wired into place months before the grafting has taken place. The reason is because the branches will lignify in fall and early winter making them hard and difficult to bend. If you're not careful, it's easy to break the shoot. If that happens, you'll have to wait a whole season before it can be attempted again.

This is experience speaking. Plan ahead. Allow the shoots to extend. Wire them into place before they fully lignify. Have a backup.

 

[markyscott]

In terms of the how, it's pretty straightforward.

First cut a groove into the trunk. When you're grafting a small shoot, you can just cut a "V-shaped" cut. If you have a larger shoot or one that where you're really trying to minimize scarring, try to cut a groove like a dovetail join - a bit wider on the inside than the outside - so that as the shoot widens it is forced deeper into the groove.

Here's a V-cut.


On the branch to be grafted, scrape away the bark from both sides and expose the green layer underneath. On the part of the branch facing the trunk, scrape away the bark and cambium so that there is no growth on that side. Then, secure the graft into the groove with some staples and cover it all with cut paste.


The staples I use are specialized grafting nails. You can get them from Bonsai Tonight.