Propagation: Easy summer grafting technique for Japanese Maples

Would anyone would like to hear about the easiest method for grating Japanese maples in the summer?

 

Yes please.

(And welcome to the forum.)

 

Thanks. This looks like a place I could spend a lot of time.

This is a great method for summer grafting. Especially for the "backyard grafter"
1. Understock should be potted up and already established in a quart or gallon size pot.
2. This method should be used in summer. (mid June-mid July.)
3. The understock should be actively growing and given extra water the week before you plan to graft.
4. Make a "T" cut on the understock, (like you would if you were bud grafting)
5. Pull back the bark on each side of the T. If the plant is active and the sap is flowing, the bark will slip back easily, exposing the cambium layer.
6. Now make a side cut on your scion wood as if you were doing a side veneer graft.
7. Slip the scion into the T cut. The bark will naturally envelope back over scion.
8. wrap the graft.
9. You will have a high % "take" with this method because you will have maximum cambial contact. I normally have 90% or better with this method.
10. Be sure to place the new grafts in a warm, shady spot.

 

Cheers, very interesting. Thinking of doing some summer grafting next year and will give this method a try. I would very much fall into the category of backyard grafter (aspiring).

I have a couple of questions, if you don't mind, about this technique:
What range of stem diameter is best for the understock?
Do the leaves need to be removed from the scion wood?
Is there any need for bagging or misting etc? (Won't be an issue if the leaves are removed)
Roughly what temperature is desirable for the "warm, shady spot"?
How long do you wait to prune off the top of the understock?

That turned out to be more than a couple of questions, many thanks in advance.

 

Great questions.
I normally use 3/16 or 1/4" understock. And on rare occasions 1/8 and 3/8.
Yes, the leaves should be removed.
I do winter grafting and summer grafting. I have never bagged and misted the newly grafted trees.
I like to time my summer grafting with the weather forecast. The week following the grafting should be nice and hot. 80's preferably.
I am placing the new grafts in a greenhouse with 60% shade.
I prune off a portion of the understock 2 weeks after I graft. I leave around 6 inches of the understock above the graft. Cutting the understock at this time will stimulate the tree to flush out the new graft. NEVER cut the understock all the way down right away with a newly grafted tree. You will run a huge risk of the understock dying back below the graft union. I like to wait until the following spring to cut the understock back all the way. At that point the new graft has become very strong and die back is not an issue.

 

Thanks for this suggestion. I have a miserable success rate with summer grafts.

Could you post some pictures of this technique??

 

Thanks for your great input, Goshiki.
It's good to have you aboard.

 

your welcome. I'll snap some pictures the next time I am grafting.

 

Thanks for the info. This looks like a straightforward technique. I plan on a trial with this method next summer. 90% success sounds great

 

Has anyone tried this method?

 

No, not yet, but thanks for bringing it back to the top, it has reminded me to give it a go. The original post was in September 2010 and i had forgotten about it by summer 2011!

 

Goshiki,
Thank you for sharing great info on summer grafting.
I definitely will give it a try. Since I have a few rootstock from the spring failed graft, do you think it is good enough to try for summer graft or should I wait until next year?. I like the no bag, no mist thing.

 

Thanks for the tips: I've tried spring grafting on a (very) few trees and I've had 0% success so far. Since I have some understock trees, I'll try this and let you know if it works.

 

Hi,

I just tried a few summer graft this weekend using your techique and I would like to ask you an additional question ref. to the graft before I proceed with a few more.

When i cut the T section and pealed/lifted each corner up in order to insert the scion, it seems a bit difficult to close up the T or wrap it up after the scion was inserted in. I sliced the scion on both side like we do with the veneer graft.
Also when you insert the scion, are you insert it with an angle of 15 or 25 deg or straight down at the T cut?.

Thank you so much for your input.

 

Atapi,I'mn ot sure if the OP still views this...I hope he does and can advise us all.
Although I haven't tried this method,I've always understood it to be thus....
When you peel the bark back it exposes the cambium attached to the main stem,there is little to no cambium attached to the bark.Therefore it is unnecessary to slice both sides of the scion.The beauty of this method is that you don't have to line up really thin lines of cambium as the cut surface of the scion mates against nothing but cambium tissue.It shouldn't matter if you cannot close the 'Tee' as it is just bark against bark on the outside,as long as you cover the whole area to stop drying out(especially as you've cut both sides of scion).I would also imagine keeping the scion vertical would be best.
Let us know how it goes :)

 

Hello Houzi,

Thank you for your input. It makes more sense to me now. We just need to assure one cut side of the scion makes full contact with the cambium of the root stock, got it now.
I will give it another try and I will let you know how it turns out in a few weeks.
Thanks again.

 

Just tried 1/2 dozen of these myself.I usually damaged the top of the 'T' trying to prise the slit open but once started the scion slipped into the slit opening it up as it was pushed down,the bark holding it nicely in place.This looks like a easier way to graft onto larger than scion rootstock,matching cambium on both sides of larger rootstock is fiddly.
Like others I've had less success when summer grafting but have learnt the hard way there are 2 things you must do.
1/no matter how fat and sassy it looks,don't try grafting this years growth.9/10 times it fails,always use last season's growth or older and snip off any new growth.
2/make sure the graft is kept hot&moist.Without a spray system this means humidity,it wants to be like a tropical greenhouse but not cooked.In hot weather a simple bag will do in shade or an opaque one in sun/part sun if cooler.Unless you have a greenhouse full of plants don't use anything more than about 18" tall(eg those tiered grow-houses) as the humidity stays at the top.I usually lay them down in a cloche but for these grafts I've layed them on their side in a heated seed propagator(they don't have to be upright)and you can also stack them on top of eachother.They should only need to be kept in this environment for about a week or so,long enough to callous over,then can be moved to a sheltered shady spot.
Good luck,it'll be interesting to see the results.My usual problem in summer is finding old growth that hasn't got new growth I want to keep :)

 

Hi Houzi,
Wow, thank you for the hands-on tips esp. the second (hot&moist) tip.
This one seems to be a tricky one where one needs to find a not too hot but moist enough for the callus to take place. I don't have a green house but thinking to place a few of them inside the shed with the door open plus a few bucket of water to get some humidity, as an experiment. I am a bit hesitate about cover the scion with plastic bag since goshiki4me said he never used one but to add moisture the bag would helped. Did you use bag on yours?.

 

Sounds like the OP has the luxury of a greenhouse.I don't think the shed idea will be moist enough.As I said I usually use a cloche but you need something to create a humid environment.An unheated propagator,an empty bottle with the bottom cut out....anything....I don't mean bag the scion as in winter grafting....a bag over the whole thing elastic banded round the pot is the simplest way to produce a mini greenhouse.I'd have to use an opaque bag with some sun as it's not hot here presently but you may be able to use a clear one in shade if it's hot there...experiment with position/light to achieve a nice hot moist environment.

 

Houzi,

I grafted about two dozen the past weekend. I finally realized what you mean by using the 'cloche'. Since my rootstocks are in a 1gal pot so I used the clear plastic bag using for dryclean, tight the top then cover six pots together; a few hrs later I begin to see the humidity formed inside the bag.
I find this method is fairly simple since we don't have to line-up the cambium like other methods. I found after making a T cut it is easier if I track the knife from the bottom T goes back up to peel the bark from each side.
How did you slice your scion? (1/3 or 1/2 of the diameter)
Since we tap the scion to the rootstock like this, will it held together after the cambium is taken?.

Thanks.

 

Yes that sounds fine,you've created a mini greenhouse.Just keep an eye out for fungus,it's a perfect environment for it though I haven't had any problems as they're not in there very long.
I cut my scions right through from one side only forming a wedge shape,simply to make less of a bulge under the bark.I shouldn't worry though,we're basically creating something similar to the old side veneer graft where the scion is slapped on the outside of the rootstock though I expect there'll be a little extra strength provided by the bark covering.Though I've seen a few videos online about the side veneer graft I've never actually seen one on a JM,they all seem to be the side graft with the flap now which I personally think is better and actually easier.
.

 

Sorry Atapi,just grasped your last sentence...I'm gonna err on the side of safety and leave the rubbers on for a month,let the graft strengthen.Just noticed some petioles have fallen off some scions,an encouraging sign.Looking forward to the weekend,will take a peek inside the rubbers on a couple,see what the result looks like,then hopefully out of their little hothouse and put somewhere more comfortable and wait :)

 

Hi Houzi,

Thank you for the additional answer.
I looked over them this weekend and see no sign of making yet. I am experimented with Goshiki4me suggestion by taking two cloches off and see what it will do. I still have other clinghe on for at least another week like yours.
I assume we do not water any of them now and if it rains then it is OK or i will need to seek for their shelters.

I can't wait to see/hear what yours look like since I grafted mine a week after you.

Thanks.

 

Well you'll have a long wait Atapi....another resounding failure:( ha ha. Of the 6 I grafted only 2 look like they've taken,and one of those was a normal graft.I accidentally knocked it breaking the join(conformation that they're still weak)so I've probably lost that one too unless it knits back together.
This is very frustrating,in winter I have over 90% success,I have quite good results in very late summer going into autumn,but summer grafting...I still haven't nailed it.
It was because of this I previously sought advice from a professional nursery who graft over 40,000 maples at this time of year.They told me about the need for humidity and using old wood,2 points I hadn't previously adhered to.Also that their 2ft high covered growing bed is stifflingly hot when they go into it.
I have a feeling that the heated propagator I used may have got too hot as the rubbers had started to weld themselves together making them hard to unwind.Anyway I won't give up,I've got more rootstock arriving soon and will adhere to the 2points mentioned and go back to using the cloche which will be cooler.I reckon the heat required depends on where you keep them,a large greenhouse will need more heat to be humid whereas an individual bag would need little or none.
I think I grafted the same weekend as you Atapi.I took them out of the propagator after a week.Don't expect to see much when you do,they won't look any different.Summer grafts aren't as exciting as winter,they don't always produce any growth the same year.Cutting down the rootstock quite low(a couple of inches above graft) may stimulate growth but not guaranteed.You can leave a leaf or two on the scion though I prefer not to.It doesn't seem to make any difference to results or encourage growth,but it provides reassurance graft's still alive.
Good luck with your grafts Atapi,I hope you have better results than me :)

 

Houzi,

~90% success in winter is quite a hi-number to achieve here, my hat is off to you.
I didn't get much from last winter due to poor condition. A year before I tried the cloche way in my basement but fungus killed them too.
Anyway so i am excited about this summer graft technique. I am experimenting it with various options. I try both 2 yrs and 1 yr wooded scion, with & w/o cloche...
I will share with you if any sight of making by the end of this weekend (second week) and probably begin to cut down a bit of those root stocks.
Thanks again.