Juniper Grafting Results and Observations

[DrBonsai]

See: https://www.bonsainut.com/threads/juniper-whip-splice-tongue-grafts.26610/
In early March I made 12 grafts of itoigawa foliage on to Juniperus scopulorum.
They all stayed green until July, then there appeared to be some browning of some grafts.
I kept the bags on until September and made sure the moss stayed moist.
I cut open the bags but left remnants to hold moss and moisture when watered.
Yesterday I removed the bag remnants and parafilm tape holding the grafts in place.
My results were as follows:
Out of 12 grafts, MAYBE 4 were successful.
4 appeared to graft and were attached but had brown foliage.
4 appeared to be loose, no graft or attachment at all and brown.


The apparently successful grafts were all on the upper branches of the tree.
My possible conclusions were that either grafts are more successful on smaller, younger apical branches and/or
I had more practice on the latter more apical grafts and demonstrated more practiced technique working my way up the tree.
Does anyone have an opinion on the class of grafts that appeared to "bond" to the tree but yet appeared brown or dead ?
Do you think the grafts were initially successful but then died due to excessive heat in summer or other reason ?

 

[Quince]

3rd possible conclusion: grafts are more successful on apical branches due to greater vigor in apical branches.
Just a thought.

 

[Eric Group]

I don't see much potential in the tree you are grafting onto... kind of just an arrow straight telephone pole. Find something with more interest...

If this is just a learning experience, I would go with what Quince said- Juniper tend to heal slow, so you need to graft onto vigorous stock. If the tree doesn't grow rapidly around where the grafts were done it will take years to heal over.

 

[0soyoung]

My thoughts are that if one simply presses two pieces of wood together, there will still be a gap on a cellular level between the two. In other words, water and minerals will not be transported across the mechanical junction.

So, the growth of new xylem is required to 'weld' the scion to the stock so that water will be carried to the scion's foliage.

This is why we must bag the scion foliage - prevent desiccation in the meantime. Further, I think this explains why grafts tend to be more successful with and on younger stems - the incremental xylem ring is proportionately wider than in an old/thicker stems.

 

[DrBonsai]

Thanks for your replies. I decided to try to practice grafts on this tree because I didn't like the foliage and it was only at the end of the branches.
I was interested in trying to learn why some grafts appeared to "weld" but did not appear to survive. You often can learn more from your failures than your successes.

 

[sorce]

I imagine if you practiced on a good trunk....
You would be kicking yourself for holing it up!

In that regard....very well done!

But...they graft JBP in fall.
Seems a better time to graft Juniper too.

But IMO....none of the shit they say about Junipers is true for us, timing wise.

They...being anyone that can not take a day trip to Lake Michigan.

So if they told you to graft In spring.
They are dead correct for themselves.
And dead wrong for you.

I believe I'll call this...

The Great Lakes Adjustment Phenomenon.

Try around the Solstice. Rampant growth between then and dormant should be good.
Then, anything still almost there can rest in a wet winter.
Whereas now, you had them resting during a hot dry period.

It could very well be that your cambium didn't match up though.
Hair splitting sharp knife?

Sorce

 

[DrBonsai]

I always thought you don't graft in the fall unless you can guarantee the grafts won't freeze.
That's why late winter/early spring is the time in Chicago.
......Unless you have a greenhouse or temperature regulated cold storage.