Author Topic: What is the best grafting method for large avocado rootstock?  (Read 2096 times)

Owen H

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What is the best grafting method for large avocado rootstock?
« on: November 28, 2021, 08:04:38 PM »
I have several large diameter avocado rootstock, some as big as my thumb and 4-5 feet tall. What is the best grafting method for this size of rootstock? I have seen veneer grafts recommended, but I am open to suggestions.

Thanks in advance!

spaugh

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Re: What is the best grafting method for large avocado rootstock?
« Reply #1 on: November 28, 2021, 10:59:44 PM »
thumb size is kind of a hard size because its too big to do a normal cleft graft and on the small size for bark grafts.  Vaneer is a good option because the sizes dont need to match that closely and you can put multiple grafts on.  You could try doing some small bark grafts also above the vaneers.  If you do vaneer grafts only, you can leave the top on the tree for 6 weeks then once the graft is well healed lop the top off to force the graft to grow.  Also remove all other suckers and shoots off the rootstock once you are confident the graft is healed and has taken. 

the downside to vaneer grafts is they usually end up with a little kink where the graft was.  Its good to tape the scionwood against the trunk above the graft to try and get it as straight vertical as possible.  So it doesnt grow sideways.  Also vaneer grafts tend to be more fragile than clefts o bark grafts.  You need to keep it taped and possibly staked and supported longer so the vaneer doesnt rip off.  Especially with a larger rootstock, the graft can grow back rapidly and get heavy and want to rip off the tree.  It can work well though you just need to do more aftercare with some types of grafts. 

You can also do offset cleft grafts and just only match the cambium on one side.  Thumb size is a little large to do this with but finger size is ok.  The grafts usually take with this type of graft but the bigger the diameter and more mismatched the sizes are, the longer it takes to heal.  You could try some of these types on the smaller ones if a regular cleft is not going to match up and do some vaneers under the offset clefts also.
« Last Edit: November 28, 2021, 11:17:14 PM by spaugh »
Brad Spaugh

Owen H

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Re: What is the best grafting method for large avocado rootstock?
« Reply #2 on: November 29, 2021, 11:47:42 AM »
Thank you, these tips are very helpful. I will try some side cleft and bark grafts too.  Hopefully I'll end up with a few healthy trees.

thumb size is kind of a hard size because its too big to do a normal cleft graft and on the small size for bark grafts.  Vaneer is a good option because the sizes dont need to match that closely and you can put multiple grafts on.  You could try doing some small bark grafts also above the vaneers.  If you do vaneer grafts only, you can leave the top on the tree for 6 weeks then once the graft is well healed lop the top off to force the graft to grow.  Also remove all other suckers and shoots off the rootstock once you are confident the graft is healed and has taken. 

the downside to vaneer grafts is they usually end up with a little kink where the graft was.  Its good to tape the scionwood against the trunk above the graft to try and get it as straight vertical as possible.  So it doesnt grow sideways.  Also vaneer grafts tend to be more fragile than clefts o bark grafts.  You need to keep it taped and possibly staked and supported longer so the vaneer doesnt rip off.  Especially with a larger rootstock, the graft can grow back rapidly and get heavy and want to rip off the tree.  It can work well though you just need to do more aftercare with some types of grafts. 

You can also do offset cleft grafts and just only match the cambium on one side.  Thumb size is a little large to do this with but finger size is ok.  The grafts usually take with this type of graft but the bigger the diameter and more mismatched the sizes are, the longer it takes to heal.  You could try some of these types on the smaller ones if a regular cleft is not going to match up and do some vaneers under the offset clefts also.

Jack, Nipomo

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Re: What is the best grafting method for large avocado rootstock?
« Reply #3 on: November 29, 2021, 12:53:15 PM »
You might want to wait until January or February to do your grafting.  The CRFG chapter in San Luis Obispo has a scion exchange then and there will be avocado scion wood available (if it is held this year...Covid)

Also, many of us have experienced greater successes by grafting in Jan or Feb, and greater failures at other times.  Today, in Nipomo it will be 81 degrees...not good for a newly attached scion.
 Also our humidity is down in the 20s. There are many avocado varieties growing in our local area (thanks to Julie and UCR and others) and they tend to show up at the scion exchange.

One issue grafting a larger stock (rootstock) is, as spaugh mentioned, the sideways weight of the growing scion pushing the graft union out.  A cleft graft on one side of the stock can connect well, leaving the other side of the cleft to dry out and die.  There are remedies for both, but require continued attention.


sc4001992

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Re: What is the best grafting method for large avocado rootstock?
« Reply #4 on: November 30, 2021, 04:11:55 AM »
Here's what I do with a rootstock your size. Just match the scion wood to the rootstock nearest the tip of the center branch, do a cleft graft at that position. Your graft will grow faster if you use the central leader/main truck of the rootstock. Also leave a few evenly growing side branches to use later for other varieties you might want to graft or for the same variety as the main graft. Just remember that the rootstock where you make the cutting to graft must be hardened for the it to do well. Probably will be at about a 1/4" diameter rootstock area that is hardened wood.
In 2 yrs you will not be able to see where the graft was made. The trick for a beginner is to know where the rootstock is hardened when you cut it to check before grafting the scion wood.

I don't like the veneer graft as Brad mentioned it will leave an offset for a while and it could break off if you don't properly support it for a year. Also looks bad and takes a while before it blends it with the rootstock. I did some veneer grafts on mango plants (5 gal plant) and it takes a few years before the graft heals good, but still looks ugly to me.

I do cleft grafting for all my larger loquat seedling rootstock (2-3 yrs old). Once the graft grows out about 6" then you can remove all the unwanted side branches below it and any new buds on the main truck.

I also agree with Jack, wait until Jan-Feb, it's the best time to graft with high success rate.

Mark in Texas

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Re: What is the best grafting method for large avocado rootstock?
« Reply #5 on: November 30, 2021, 08:06:02 AM »
I have several large diameter avocado rootstock, some as big as my thumb and 4-5 feet tall. What is the best grafting method for this size of rootstock? I have seen veneer grafts recommended, but I am open to suggestions.

Thanks in advance!

Veneer or stub, wait for shoots to push and when they get to the girth size you want, cleft graft.  You could also try t-bud.  Just make sure the bark is slipping.  I use a Schick single injector blade on all of my cuts.  Slice your T stopping at the cambium and with your thumbnail flick the top corner open.  If it opens cleanly, you're good to go.   Here's citrus t-bud.









Wrap with Buddy Tape.
« Last Edit: November 30, 2021, 08:11:14 AM by Mark in Texas »

Mark in Texas

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Re: What is the best grafting method for large avocado rootstock?
« Reply #6 on: November 30, 2021, 08:09:50 AM »
Did a veneer graft on Reed and a recent graft of JB on a Bacon stub.  They are doing well.

Veneer graft on Reed, 2012:



I keep my Reed trimmed to 12' or less. It's a very vigorous tree, this after being kicked in the branch crotch by extreme temps of 112F, 18F, and 21F.



« Last Edit: December 17, 2021, 09:06:09 AM by Mark in Texas »

sc4001992

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Re: What is the best grafting method for large avocado rootstock?
« Reply #7 on: November 30, 2021, 11:20:59 AM »
Mark, I have a question for you on bud grafting. I have never used it for any of my fruit trees and not on my citrus. Do you know which grafting method would result in the grafted branch to grow faster/larger? To me it seems the bud grafts would take longer for the new bud/branch to grow out so in 2 yrs after you graft, the cleft/veneer grafted branch would be larger (and have fruits earlier). My goal in grafting most of my fruit trees is to have fruits on the new variety to eat or taste so I can determine if I want to to keep or not. If I can't get much scion wood of a particular variety then I can see doing the bud grafts (citrus, figs, persimmons, white sapote).

Mark in Texas

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Re: What is the best grafting method for large avocado rootstock?
« Reply #8 on: November 30, 2021, 11:53:06 AM »
Mark, I have a question for you on bud grafting. I have never used it for any of my fruit trees and not on my citrus. Do you know which grafting method would result in the grafted branch to grow faster/larger? To me it seems the bud grafts would take longer for the new bud/branch to grow out so in 2 yrs after you graft, the cleft/veneer grafted branch would be larger (and have fruits earlier). My goal in grafting most of my fruit trees is to have fruits on the new variety to eat or taste so I can determine if I want to to keep or not. If I can't get much scion wood of a particular variety then I can see doing the bud grafts (citrus, figs, persimmons, white sapote).

Have found that the type of graft makes no difference.  There's way too many other factors at play that drive vigor.

sc4001992

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Re: What is the best grafting method for large avocado rootstock?
« Reply #9 on: November 30, 2021, 12:52:05 PM »
Ok, thanks for your reply.

beicadad

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Re: What is the best grafting method for large avocado rootstock?
« Reply #10 on: November 30, 2021, 02:31:07 PM »
For citrus with lots of branches, it seems to me that it often takes forever for buds to push. Cleft worked better for me

sc4001992

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Re: What is the best grafting method for large avocado rootstock?
« Reply #11 on: November 30, 2021, 04:20:04 PM »
Yup, I agree. I have never used the bud graft on my citrus grafts since it does have many nice branches to use for cleft as you said. Just like my loquat trees, I can graft a lot more varieties just by using the many branches on the tree for my multi-grafted tree.

MasonG31

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Re: What is the best grafting method for large avocado rootstock?
« Reply #12 on: November 30, 2021, 06:58:13 PM »
For large diameter avocado rootstock, modified cleft graft works best for me.  It has a high success rate, maybe even higher than the regular cleft graft.  At least for me it does.  Good luck!

ScottR

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Re: What is the best grafting method for large avocado rootstock?
« Reply #13 on: November 30, 2021, 07:36:08 PM »
Excellent advice from Jack, Kaz, Brad,and Mark I live closer to Ocean than Jack, but on Mesa and we have found out through many years that grafting avocado's in our area of Calif. works best in Jan-Feb.
Owen, the challenge for you in Atascadero is cold in Winter time so, if you do top work your trees using which ever graft but paper bag over your graft's that's what i do until they start to push new growth. I use modified whip & tongue.


Owen, you can go to CRFG-Central Coast Chapter.org and see Newsletter to check latter in Dec or Jan. for sure to see if we will be having scion exchange. I manage scion exchange with my wife and we don't know yet if we will have exchange because of Covid.

canito 17

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Re: What is the best grafting method for large avocado rootstock?
« Reply #14 on: November 30, 2021, 08:43:09 PM »
Hi


canito 17

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Re: What is the best grafting method for large avocado rootstock?
« Reply #15 on: November 30, 2021, 08:47:41 PM »
Vaneer with Green bark


Owen H

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Re: What is the best grafting method for large avocado rootstock?
« Reply #16 on: December 01, 2021, 03:48:27 PM »
Thank you Scott, Jack, Mark, Mason and everyone else! This thread is extremely helpful.
I know that Atascadero is probably marginal at best for growing the most cold hardy avocados. Is anyone aware of any mature avocado trees in Atascadero or north San Luis Obispo county? The rootstock I have is an assortment of aravaipa, duke, and mexicola. I have been planning to buy scions from fruitwood nursery since they have a selection of more cold hardy varieties.
The rootstock is in my heated greenhouse, and I have 50% shade cloth over half where I plan to do the grafting. I think I will try a variety of grafting methods with the suggestions here.

Excellent advice from Jack, Kaz, Brad,and Mark I live closer to Ocean than Jack, but on Mesa and we have found out through many years that grafting avocado's in our area of Calif. works best in Jan-Feb.
Owen, the challenge for you in Atascadero is cold in Winter time so, if you do top work your trees using which ever graft but paper bag over your graft's that's what i do until they start to push new growth. I use modified whip & tongue.


Owen, you can go to CRFG-Central Coast Chapter.org and see Newsletter to check latter in Dec or Jan. for sure to see if we will be having scion exchange. I manage scion exchange with my wife and we don't know yet if we will have exchange because of Covid.

Owen H

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Re: What is the best grafting method for large avocado rootstock?
« Reply #17 on: December 01, 2021, 03:53:14 PM »
So that would be a cleft graft off to one side of the rootstock to closer match the diameter of the rootstock? This sounds like a simple solution. I do have experience with cleft grafting on other trees (not avocado)
For large diameter avocado rootstock, modified cleft graft works best for me.  It has a high success rate, maybe even higher than the regular cleft graft.  At least for me it does.  Good luck!

MasonG31

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Re: What is the best grafting method for large avocado rootstock?
« Reply #18 on: December 01, 2021, 06:56:00 PM »
So that would be a cleft graft off to one side of the rootstock to closer match the diameter of the rootstock? This sounds like a simple solution. I do have experience with cleft grafting on other trees (not avocado)
For large diameter avocado rootstock, modified cleft graft works best for me.  It has a high success rate, maybe even higher than the regular cleft graft.  At least for me it does.  Good luck!
Yes exactly.  Good luck.

Jack, Nipomo

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Re: What is the best grafting method for large avocado rootstock?
« Reply #19 on: December 03, 2021, 05:26:54 PM »
Owen, climate is changing....when we first moved to Nipomo local nurseries did not think we could grow avocados.  We consistently had low 20's during the winter with long duration.  Between freezing years I grew up different tender trees to the point of having some success.  We used covers, return stack heaters (lots of diesel), and sprinklers.  We therefore had limited success.  Now, we see bare 28 degree winters rarely, short duration, don't see any frost damage.  One year 45 yrs ago we had 17 degrees, killing many eucalyptus growing in the area.  Our 40 varieties of avocados are mature, about 45 macadamias doing well, and white, yellow, black sapotes undamaged.  Last year I planted out 6 mangos, put another 8 in the greenhouse.  All will be out this Spring.  I did encircle and cover the outside mangos for 2 nights last year.  I will be planting out some other subtropicals this Spring also like Monkey Orange, Nance, and two lychees (Already have had Longans out for years).  Don't know how cold you get in Atascadero, but life is short and planting out these "rare" fruits is a gamble.  I'm more worried about our reduced rainfall.  Then again, now maybe I've brought down the gods of the freezes as a result of the aforementioned.

ScottR

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Re: What is the best grafting method for large avocado rootstock?
« Reply #20 on: December 03, 2021, 07:06:21 PM »
Owen, climate is changing....when we first moved to Nipomo local nurseries did not think we could grow avocados.  We consistently had low 20's during the winter with long duration.  Between freezing years I grew up different tender trees to the point of having some success.  We used covers, return stack heaters (lots of diesel), and sprinklers.  We therefore had limited success.  Now, we see bare 28 degree winters rarely, short duration, don't see any frost damage.  One year 45 yrs ago we had 17 degrees, killing many eucalyptus growing in the area.  Our 40 varieties of avocados are mature, about 45 macadamias doing well, and white, yellow, black sapotes undamaged.  Last year I planted out 6 mangos, put another 8 in the greenhouse.  All will be out this Spring.  I did encircle and cover the outside mangos for 2 nights last year.  I will be planting out some other subtropicals this Spring also like Monkey Orange, Nance, and two lychees (Already have had Longans out for years).  Don't know how cold you get in Atascadero, but life is short and planting out these "rare" fruits is a gamble.  I'm more worried about our reduced rainfall.  Then again, now maybe I've brought down the gods of the freezes as a result of the aforementioned.
:o Now you did it Jack ::)
« Last Edit: December 04, 2021, 11:39:11 AM by ScottR »

slopat

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Re: What is the best grafting method for large avocado rootstock?
« Reply #21 on: December 04, 2021, 12:59:23 AM »

When I planted my bacon back in the late 80s, the nursery man said it was best for handling the cold in SLO! Now mangos, longans, lychee, etc. possible? Crazy, like the occasional snow on the grade!

Anyways,  I have 10+ seedlings ready to practice grafting in Jan/Feb so this is good discussion. Two mango trees that are still growing too!

Growing fruits definetely has better ROI for the mind  than frustration with either golf or video games :)

Owen H

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Re: What is the best grafting method for large avocado rootstock?
« Reply #22 on: December 04, 2021, 05:04:18 PM »
Thank you for the encouragement, Jack. It sounds like you have had an interesting career in growing fruit and seeing the changes in our climate. We still get low 20's up here maybe every other year, but nothing like 30 years ago when I was a kid. I remember low twenties and teens frequently and having to break thick ice in the horse's water trough every morning. No one grew citrus here when I was a kid, but now you see them around and mine do fine unprotected.
That's great you are able to grow such a variety of plants down there. I have some more tropical plants in the greenhouse that are doing well but still far from fruiting. I think I will try a white sapote up against the house to see what happens. I look forward to checking out the upcoming CRFG scion exchange. I've wanted to go in the past but haven't been able to make it.


Owen, climate is changing....when we first moved to Nipomo local nurseries did not think we could grow avocados.  We consistently had low 20's during the winter with long duration.  Between freezing years I grew up different tender trees to the point of having some success.  We used covers, return stack heaters (lots of diesel), and sprinklers.  We therefore had limited success.  Now, we see bare 28 degree winters rarely, short duration, don't see any frost damage.  One year 45 yrs ago we had 17 degrees, killing many eucalyptus growing in the area.  Our 40 varieties of avocados are mature, about 45 macadamias doing well, and white, yellow, black sapotes undamaged.  Last year I planted out 6 mangos, put another 8 in the greenhouse.  All will be out this Spring.  I did encircle and cover the outside mangos for 2 nights last year.  I will be planting out some other subtropicals this Spring also like Monkey Orange, Nance, and two lychees (Already have had Longans out for years).  Don't know how cold you get in Atascadero, but life is short and planting out these "rare" fruits is a gamble.  I'm more worried about our reduced rainfall.  Then again, now maybe I've brought down the gods of the freezes as a result of the aforementioned.
:o Now you did it Jack ::)