What is the latest you can graft apples?

General Fruit Growing
#21

@Jla, it’s less about the sugars to the roots than it is about apical dominance.

At the tip of each branch is a terminal bud -it’s apical bud, the bud at the apex. That bud secretes a hormone called “auxin” which discourages the growth below it from becoming overly competitive. Otherwise the tree would choke itself in the interior by filling up with new growth. When that bud is removed buds below it emerge.

Thus when we place a bud or chip below the terminal bud they lie dormant -unless the terminal bud is removed.

But when we place a scion we typically cut off the terminal bud in the process (unless we’re making a side graft.) So the terminal bud is not there to suppress the growth of the scion’s buds.

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#22

you have 3 different mechanisems in grafting.

1- The ticking clock ie the concept of time
The scion has no accses to resourches, until it has a conection to the roots of the stock.

So once you graft, the clock starts “ticking” However if the scion is dormant or has no leave. It evaporates verry little and needs verry little resourches to stay alive. So the clock ticks verry slowly.

however once a dormant scion starts leafing out. It needs those resourches and also starts to evaporate a lot of water from the leafs. So your clock is ticking verry fast.

good things
-having scion stay dormant till healed.
-wrapping the scion in parafil or somthing else (shade for example) to reduce evaporation.
-having a strong scion with a well developed bud (more resourches and moisture stored. can survive for longer)

The other part is
-2 Healing
When grafting your wounding both the scion and the rootstock. both of them will start to heal. You also see this in the fridge (usualy scionwood can callous at the bottom where it’s been cut off the tree, in the fridge)

So the callous is basicaly the wound healing.

However, once the 2 callouses meet. Somthing magical happens and the callous changes from just “stem cells to repair wound” to vascilar cells. And thus starts trransporting water and resourches from the rootstock to the scion.

This is when the graft is healed (or sucsesful)

Good things
-having the rootstock do most of the callousing. Since the rootstock has accses to roots and way more resourches it can easaly grow lots of callous. No problem.
The scion however has little resourches.
-having the scion stay dormant and slowly produce callous, while the rootstock wakes up and grows callous fast.
-having the cambium be close together between the scion and the rootstock. Less callous needed before they “meet” and grow together.

-3 the graft not just making a leaf but actually growing a shoot.
to start forming the tree

When the graft is healed. The scion and the buds on the scion have accses to water and nutrients. However this does not mean it will start to grow a branch/tree.
There are thousands of buds on a tree. But only a few form branches.
The tree regulates/chooses which buds grow a leaf and which ones grow a shoot (branch) by hormones. Doing certain things can make the tree “choose” your graft to start growing a shoot/branche

good things
-having your graft be the highest point on the tree/branch. The hormones that make a bud grow into a shoot, move upwards to the highest point.
-having a strong rootsystem/rootstock. The roots make the hormones that make the buds grow into shoots. Stronger rootstock makes more hormones, so you get more shoots. So a strong mature tree can easily grow out hundreds of grafted branches. But a small 1 year old rootstock might struggle to grow 2 buds into shoots.
-having no bud or growing shoot above your graft. The growing shoots give off hormones that surpres the buds below them from growing a shoot. This is also why you usualy prune just above your graft after it has healed.

good things

#23

more in reply to what you typed. Like Marknmt said. it’s less about sugar. The tree has plenty sugar stored in the wood of the branches and in the roots.

It’s all about the hormones.

If the tree has active growing shoots, those form auxines.The auxines move down to the roots. They make sure the buds they pass on their way to the roots below them do not grow a branch.

If the tree has active growing roots, they produce cytokines. They move upwards, and save up in the highest part of the branches. they promote buds to grow new shoots.

If you prune a tree heavy, your taking away a source of auxines. But the source of cytokines remains the same. So there is no inhibition of growing new side shoots by the auxines. And loads of promotion of side shoots by the cytokines.

The opposite can also be true.

If you damage the rootsystem a lot by transplanting. But don’t prune the tree aboveground. It has lots of tips, that produce auxines. But little roots to produce cytokines. So the tree uses most of it’;s resourches to grow more roots, and growth aboveground slows down.

It’s the tree’s natural way of balancing the size of the roots and the size of the tree aboveground to match eachother.

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#24

Wow that’s such a good reply. Thank you so much for your help you’ve really shed a great deal of light on this for me. So now I understand that grafting the wrong technique ie whip and tongue or veneer graft, whichever, at the wrong time forces a piece of wood to grow before its proper time, ie before the union of scion-stock has fully formed…
Whereas a chip remains dormant until you sort of press the “go” button and remove the apical bud. Grafting techniques however remove this tip bud as part of the technique process and thus that’s why it doesn’t work. I understand now. Thank you both very much.

#25

hhm, no not really it has little to do with the grafting technique. timing wise you can virually always use chip bud and W&T at the same time.

Keeping the scion dormant has more to do with pruning the scion in winter and keeping it cold (fridge for example)

With the W&T the graft already “prunes” your stock. So the W&T is already the highest point (unles you graft on a bend down branch, but than you can just bend it up)

However with the chip bud and somtimes side veneer graft. you after to prune the stock. To make sure your graft will grow a shoot instead of a leaf. (or even stay completly dormant)

there is also a difference between winter(spring) and summer grafting.
For winter/spring grafting you use dormant scions that where cut during the winter.
These are dormant. But will slowly wake up when the temperature rises. Or when the rootstock pushes enopuogh hormones into them.

For summer grafting you cut of a branche while it has leaves. You cut off the leaves (you can leave the leaf stalk) and where the leaf stalk connects to the scion. There is a little bud. This bud will remain dormant untill it gets chilled in winter or enough hormones to wake up.

So if you chip bud this bud in summer. It will stay dormant till next spring. Unles you prune just above it.
The same goes with W&T. If you W&T in summer with a freshly cut scion on a weak/low branch it can stay dormant till next spring. However if you do it on a strong branche. You already pruned that branche by preforming the W&T so it will likely grow as soon as it is healed.

#26

Hmmmm OK… But like you sais earlier on, with the analogy of the clock ticking, if I were to use a shoot with leaves on in the height of summer and try W&T it onto, say, a plum tree, the “clock” would be ticking fast even if I removed all the leaves and so on because that scion of wood would be awake so, surely it would be the wrong time of the year to do it?
I just find as soon as I get an understanding on something I discover that I didn’t quite get it right…

So this makes sense, however, surely this above means that you CAN’T W&T in summer because a fresh cut twig wouldn’t be a) asleep and b) would require food immediately even if it was on a plum tree for example with many other branches etc it would still require food which it couldn’t get because the union hasn’t healed? Am I getting there?..
I’m sorry I’m such a slow learner.

#27

Ah i get where the confisium comes from now.

When the tree grows a new shoot in spring (from a bud) that shoot has leaves. But at the base of each leaf a new bud is also forming. This new bud usualy does not “wake up” till after it has had a cold treatment or sufficient time has passed. This bud thus is “dormant” even though it is there during the growing season.
This would be the same bud you could leave on the tree till winter and then prune off as a dormant bud. After the winter however, when it warms up it will brake dormancy and grow a leaf or shoot usualy.

You can do a W&T in summer. You just have to cut off the leaves of the scion. And wrap the scion in parafilm to avoid drying out in the heat. Painting it whithe or keeping it in shade also helps.

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#28

Ahhhhhh I get you… I get it! Thank you! I’m sorry you had to waste time explaining something that everyone on here takes as obvious knowledge but honestly finding a person to just sit and explain things to you is impossible. Thank you very for your time and patience. :pray: Honestly

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#29

So, just to make final sense of your clock ticking analogy,
Dormant does not just mean winter. Winter dormancy is a thing, but dormant just means not actively growing even on an actively growing branch…
Dormant scions use less energy because they’re asleep so in turn, a slow ticking clock :white_check_mark:
This gives time for unions to heal.
Depending when you do it ie at the start of the year, (March) if its a strong branch as you said, it may grow this season or if its a smaller weaker one, it may take the next season to get going etc…

I love those three points I’ve saved them on a screenshot :+1:

#30

Yea, dormant mainly refers to the buds. The branches are there just to support buds. The branch itself does verry little.

The branch in summer itself evaporates verry little water. The leaves evaporate a lot. So if you deleaf a branch, it can survive quite a while. Even if you cut it off the tree. Once it grows new leaves (buds no longer dormant) the clock starts ticking faster again.

The buds start out dormant when they just form. And then stay dormant trhougth the growing season. Then in winter they get “primed” and when the temperature increases in spring they brake dormancy. And depending on how much hormones they get, they either grow a leaf or a branch.

So to drive the point home. you have

1 the dormancy of the bud. Largely determined by when it was formed. (a bud formed in spring on a new growing shoot, will stay dormant till after the next winter)
A bud formed end of summer on a new shoot. Will also stay dormant till next spring. And wake up around the same time as the spring formed bud. It is the winter that “primes” them to wake up.
The bud on a twig cut off the tree in winter, will stay dormant till it starts to warm up. (thats why keeping it in the fridge can keep it dormant longer.) But once it has had enough heat, it will form a leaf or shoot (depending on hormone concentration)

2 is the plant hormone situation.
Cytokines form mostly in the roots, and move only upwards till they can go no higher.
When cytokine concentrations are sufficiently high, Cytokines do the following
-wake up buds
-force those buds to grow a new shoot/branch instead of just a leaf.

Auxines, auxines get formed the growing tips of the tree. (shoot tips).
Auxines can only move downwards.
Auxinies inhibit buds from growing shoots. (thats why there are no side branches directly below the activly growing shoot)
(But if you remove the activly growing shoot, the auxine concentration diminishes, the cytokines save up. And a dormant bud will wake up and grow a shoot.)
When the auxines reach the roots, they make the roots grow more.

So auxines and cytokines do the oposite of eachother. And depending of what there is more, buds do different things.

This is the tree’s natural balancing system to keep the correct ration between roots and leaves/branches.

so if you cut a scion in summer and de-leaf it. The buds will stay dormant. And you only have to deal with the evaporation of the branch and leaf-stalks or scars.
It will stay dormant till
-it has grown together and recieved enough hormones to be forced to wake up.
-winter has passed and it has recieved enough warmth after the cold winter period

If you cut a scion in winter. (no leaves, dormant buds)
It evaporates verry little. The dormant buds are however primed to wake up, once
-they recieve enough heat
-once they recieve enough hormones to be forced to brake dormancy.

The hormones are sort of the wild card. They can always brake a buds dormancy.

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#31

your welcome :slight_smile:

Im glad you appriciate it.

You’r quite determined, i appriciate that to :slight_smile: a lot of people just wait till some-one says somthing that sounds easy or what they wanna hear. And than move on. You seem determined to “get it”

It is really hard to judge what “piece of the puzzle” piece of information some else is missing to get the whole picture to “click”. I am glad it seems we got there :grin:

#32

I’m an apprentice at a nursery and it’s a whole new field (no pun intended) I’m learning. We’ve just finished our small lot of ornamental cherry trees (which I absolutely thrive reading about) and sorbus and fruit etc etc. But the person teaching me doesn’t always understand how my mind works but like you say I don’t need to be told the tradition and have the same point hammered hoek, I like to know WHY AND HOW it works… Not just that it DOES work. Tradition isn’t an answer its just a way of doing things.
You’ve honestly made months and months go ogling worth while lol
Seriously you should be a teacher :joy:

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#33

im the same way. want to understand the underlying mechanisem. Not the tradition.

“If tried it once and it seemed oky.”
“It’s been done that way for a while.”

Never seemed like valid arguments to me. At least not coming from a teacher or “expert”.

#34

Absolutely it’s more an admission of not knowing what you’re doing. I totally agree. :+1:

#35

Some more questions on this subject - as it gets later into the season is there any benefit to grafting with green scion vs dormant wood? I grafted this stump in late April and I’m thinking it hasn’t taken, though the leaves haven’t fully shriveled. I think I made a few mistakes, possibly cutting the tree back too far and grafting too low. The rootstock is still sending up shoots but I’ve been punching them off hoping to force growth into my scions. Do you think it’s worth unwrapping and attempting another graft? I have more dormant scions but I could also cut some actively growing wood - I’ve not really heard of that being done other than just buds in the fall.

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