Why is grafting peaches more difficult than other fruits?

General Fruit Growing
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The only kind of graft I do these days is the most basic, a splice graft wrapped with black electric vinyl tape at the union with “Buddy Tape” wrapped around any exposed scion wood. That is a pricey version of parafilm that is thinner and stretchier than the cheaper stuff.

I use a double bladed Italian hand pruner to make my cuts because it allows me to make long, clean cuts quickly. No whip and tongue, just a single angular cut of similar diameter scion and mother annual shoot. 5 minutes a graft with little dexterity needed- except when taping the union.

No painful learning process either.

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42

In our personal exchange you stated that you meant longer cool periods than 2 to 3 days and that you agreed to most everything CHAT had to say about establishing peach grafts in relation to weather after the graft.

I’m not sure if you agreed with it on the matter of callous formation continuing steadily through day and night with night temps dropping below about 60 retarding the healing process. However, graft failure as a result of a reduction in the speed of callous formation is not clear- especially outside a greenhouse.

I’m posting this so members understand that you are talking about extended rainy periods and not the typical (in my climate) 1-3 days of the passage of a rain producing front. I think that is important.

Here is a quote from CHAT- Maintaining temperatures between roughly 55 °F and 90 °F during and after grafting supports callus formation and graft success, with the critical healing period occurring in the first 7–14 days post-grafting.

This is from In Hartmann, Kester, Davies & Geneve — Plant Propagation: Principles and Practices, and the temps are related to ambient air temps, not the graft themselves.

The text suggests that the reasons for common graft failure of peaches does not lie in stretches of rainy weather, but in the limited window the species provides and the greater need for skill in cambium alignment and careful timing of scion wood harvest and good storage methods.

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I’m not ultimately interested in rain/clear or day/night or sun/shade or air temps, all that matters in the end is the temperature of the graft union. It needs to “hit the sweet spot” in that graph I posted above for enough hours, before the graft starts to become less viable. Peach grafts both have a narrower temperature window and maintain viability less long, so that makes them harder to graft. Its better to be too cold than too hot, you are missing the callous window in both cases but when its too hot you are much more quickly damaging the viability and closing the time window of when the graft is viable.

PS I looked up that Hartmann text and couldn’t find any quote like that in it.

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Do you mind sharing the brand/style?

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I think there are too many variables to arrive at any accurate specific guideline and that your graph is not evidence that timing the graft around weather patterns is a crucial element in survival, barring relatively extreme events, or that would be a prevalent feature in the general literature.

Anecdotally our sample sizes are too small to arrive at hard conclusions but there is a lot of combined evidence that the general success of peach grafts is not determined by the quickest rate of callous formation or that it is a very important issue most seasons.

On the other hand, if your own experience clearly confirms your order of essential requirements of success of peach grafts, I certainly respect your opinion and experience.

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@Alan Thanks!

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Why splice as opposed to whip and tongue ? Is it just because it’s faster? I just started grafting last year and WnT is my favorite because of how much strength it has. I have a feeling I could get Apple grafts to take with it without even using parafilm
I’m getting a bunch of peach Scion this spring. Do you just graft one year wood to wood?

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The electric tape provides more than adequate strength and the simple splice is the fastest and most reliable for matching cambium on same sized wood. Most of all, it isn’t a skill you need to master, at least not as much as a whip and tongue. I’ve taught people in 15 minutes and the grafts they make when learning usually take.

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50

Thanks I’ll try to include some of these grafts. Sounds like it’s basically a whip without the tongue ?

For material I’ve always just used parafilm. I like how it will just fall off on its own and I don’t need to manually take it off

51

Same thing with Buddy Tape, but I don’t think it matters much which you use. I just started with BT and the parafilm I got seemed so thick, I was afraid buds wouldn’t push through- that was a long time ago.

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52

These stages are irrelevant to grafting, the important thing is that the tree is actively growing when you graft. If the temperature lows are in the forties or less, failure rate becomes high. I live in Zone 6 CT, I graft dozens of grafts every year and my success rate is very high (typically 90-95%), below is a description of my technique:

1-For highest chance of success, graft on a day where temperature will be in the seventies or high sixties for at least 5 days, and no chance of dropping below 60 for the next 10 days or so.

2-Graft on a vigorous growing branch, a main or secondary scaffold or something that will be so.

3-After the graft shows signs of success, remove all vigorous growth from the branch you grafted on, but leave non vigorous growth (this is to avoid self pruning).

4-My preferred grafting style is whip and tongue (provides the highest extent of cambium overlap and good structural support), followed by cleft (good structural support), followed by bark (bark grafts often times will need to be supported till the end of the season, but not always).

5-Cut the grafting surface to be 1-2” long to maximize cambium overlap.

6-After inserting the scion in the understock, and ensuring cambium overlap, wrap the junction with parafilm (to guard against dehydration), followed by electric tape (for structural support). Before grafting, I wrap the whole scion in parafilm, and then expose the section that will be cut.

7-Cover the whole graft with brown paper lunch bag, and cut tiny slits in it for aeration (this is to protect from sun).

8-In average, I see new growth in 2 weeks, but can be as soon as 4-5 days and as long as a month.

9-If you are going to topwork a whole tree, I recommend doing it on stages, 1-2 scaffolds at a time (the whole tree will be topworked in the same season). Alternatively you can graft in all main scaffolds simultaneously as follows: Graft on a vigorous branch that is still young, and after the graft takes, do a bench pruning cut to remove the old growth and keep your graft allowing it to grow to be the new scaffold. This point is to avoid death of the whole tree from over pruning shock and to avoid self pruning of the slower growing grafts.

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53

You the man @Ahmad! I get up to 95% some years but sometimes its worse. I follow a similar approach with a few minor differences. Since you are having better odds than me take this with a grain of salt :slight_smile:

  • I find 80’s OK.
  • I usually do bark grafts and support them, because I’m usually grafting to big stocks.
  • I don’t do the lunch bag but do a similar thing with alu foil on the sunny side if it’s getting into 80s. I don’t do anything if its not in the 80’s.
  • I just topwork bigger trees all in one go. I’ve never noticed any greater chance of failure with this. If there is a natural nurse limb I will keep it though.

I think your long contact point idea (5) is great, I have recently been doing that one inspired by your approach. Also I am wrapping in parafilm now (6), I was using Doc Farwells but it doesn’t seem to work as well as parafilm. Since I started those two things my odds are more in line with yours.

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54

Thanks for the compliment :smiling_face:

Last year I grafted 7 or 8 nectarine grafts on June 8th (summer temperatures), and I had ~50% success rate. It was a late decision, and I thought it’s better than waiting another year. So, my guidance above is what have worked best for me.

I did successfully topwork two peach trees last year with a single nurse branch, but a couple of years ago I had an apricot tree die on me when I did the same. So again, I prescribe the most conservative approach, with highest chances of success.

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