Optimal temperature for callus formation (overview)

General Fruit Growing
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Hello everyone. A useful thing to know about a species when grafting is the optimal temperature where the species forms callous. I’ve collected this overview from different sources and experiments over time and am curious if you have comments, corrections, better data, sources, experiences etc.

  • Abies 20-25°C
  • Acer 21°C
  • Actinidia 15-21°C
  • Aesculus 22°C, max 18 days, medium callousing
  • Amelanchier 20°C, max 18 days, high callousing
  • Asimina 13-24°C. Usually quite light if not done very late. Leaves of 2-7 cm
  • Betula 22°C, max 18 days, medium callus formation.
  • Carpinus 22°C, max 16 days, high callus formation.
  • Carya
  • Castanea 21-22°C, max 18 days, high callus formation. High callus after 8-9 days at 23-24°C.
  • Citrus. 21-29°C.[^1]
  • Crataegus. Late winter to early spring. Highest success rate in March.
  • Cornus mas maybe 25°C.[^2] Beginning callus after 17 days at 21-25°C.
  • Corylus. 14 days at 21°C, 20-21°C, max 14 days, high callus formation.
  • Cydonia: 13-30C
  • Diospyros 21-27°C. Leaves 1-2cm. A little later than others to release the bark.
  • Fagus 20°C, max 18 days, medium callus formation.
  • Gleditsia 20C, max 18 days, medium callus formation.
  • Ginkgo 22C, max 18 days, medium callus formation.
  • Juglans even higher 25-27C, while others use just 18C, max 18 days but with low callus formation. Beginning callus after 17 days at 21-25°C
  • Liriodendron 24°C, max 16 days, high callus formation.
  • Malus 7-21, optimally 13-18. There is an early and rather strong growth period for apple, which late grafts may miss.
  • Mespilus. Closely related to Amelanchier (18C)
  • Morus 20-25°C, 18 days, high callus formation
  • Picea. 20-25C
  • Pinus
  • Prunus persica 18-27°C. When the leaves are 2-4 cm seems to be the best time
  • Prunus armeniaca 18-27°C, optimal at 20C. Like peach and almost as difficult.
  • Cherry subgenus Cerasus 13-21, optimum 20C
  • Prunus domestica and probably others in section Prunus, 13-21C (16C), e.g. Japanese plum and E plum 13-21C
  • Pyrus 7-21, optimally 13-18, like apple but lighter.
  • Punica 18C
  • Quercus 22C, max 16 days, medium callus formation.
  • Vitis 21-24C or even 27-32C. About 15 cm growth before it is typically warm enough to graft wine. Or wait until 30 cm and graft at the base of the new annual growth.
  • Ziziphus jujuba 15-27C. Should have small knot growth of at least 5mm.

1: fruitmento - grafting-citrus-trees-best-time
2: In-vitro rooting using 25C - Ďurkovič, J., & Bukovská, J. (2009). Adventitious rooting performance in micropropagated Cornus mas. Biologia plantarum, 53, 715-718. Another experiment also found that Cornus needs relatively high temperatures and that early spring (early April) has worse success rate than chip budding in August: Jaćimović, V., & Božović, Đ. (2010). The Grafting of Cornel (Cornus mas L.) by Budding and Simple Attachment. AGROZNAWE, 16.

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Carya calluses best between 21C and 27 C. Carya scionwood should be 1 year old wood with abundant large buds but not the terminal 8 to 12 inches of the stick. If the scion is NOT solid to the core, don’t use it.

Juglans tends to produce a very large and healthy terminal bud. It is far more likely to be accepted than any other part of a typical stick of scionwood. Good acceptance can still be obtained with buds lower on the stick, but they won’t be as vigorous as the large terminal bud. Juglans and carya are very similar in temperature requirements.

I’ve had excellent results with juglans using an inlay side graft where a scion is grafted on the side of a 1 to 3 inch diameter tree which is in active growth. After 10 days, cut the top off the tree about 1.5 or 2 feet above the graft. Disbud the rootstock regularly. When the scion initiates growth, tie it to the stub of the rootstock to keep it growing vertical.

Abundant moisture is required for both carya and juglans to get good acceptance. Five days without rain will stop callus production unless supplemental water is applied.

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What is the source of this data? Can it be translated into American English? It seems like it might be good information but time-consuming to understand.

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Yes. Use any on-line tool to convert C to F. And/or look up the genus of your target species (e.g., Acer = Maple).

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Interesting info.
Is this personally obtained info or from internet sources? If so, where from? Some of the info is definitely wrong if it is considered as necessary. It may be sufficient.

I’d love to also learn about total callusing time. Not just temperature.

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Says “optimal.” :slight_smile:

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What is the value of naming a maple, acer? Not trying to be difficult just trying to understand.

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No problem.

You ask, Why not use “maple”? I think the answer is that most of the world doesn’t speak English.

Linnaeus developed his naming system (genus, species, etc) in the 1750’s. He happened to be Swedish. It would have been arbitrary and arrogant for him to chose Swedish names. Thankfully, he didn’t chose Swedish names. Or French or German names, despite the prominence of French and German scientists. On the other hand, lots of scientific work worldwide used Latin. So he used Latin too. It was a politically and culturally more neutral choice.

Today, we should recognize that many of the forum’s participants are not native English speakers. They graciously communicate here in English. But we should not take English (e.g., “maple”) for granted. We have no inherent right to communicate in English.

You might also have asked, Why not use Fahrenheit? The answer is that the entire world uses Celcius, except the U.S. and its territories. At the risk of sounding political, I’ll suggest that maybe it’s time for Americans to get comfortable with the Celsius scale and switch to it.

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Interesting history lesson, thank you for your reponse.

Personally speaking… I really have no desire at my age to learn another language. I visit a site that users respond in many differnt languages. I can say participation to posts started in other langugaes beside american english receive very little if any interaction.

And F to C is not straight forward calculation either. It should be something easy to understand like + or - 32 but it’s not that way. F = C x 9/5 + 32 which to me is about like calling a maple, acer.

I try to avoid political discussions. So I wont comment on the political aspects of this discussion. Hope your not disappointed in me…

I appricate you taking time to repond to my question.

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OK, I’m not gonna judge. I’m happy if you recognize that English-speakers are a minority and Fahrenheit users are limited to the U.S. So we shouldn’t feel entitled either to American English species names or to Fahrenheit temperature measurements. Meanwhile, my advice:

  1. You don’t have to learn Latin to grasp Linneaean genus names. Just memorize the few that interest you. For me, apple = malus, pear = pyrus, mulberry = morus, peach/plum = prunus, persimmon = diospyros, chestnut = castanea, grape = vitis. That’s about it.

  2. You don’t have to tranlate every F to C manually every time. You could use any on-line app (e.g., Google “21 C to F”). And/or you could take 10 minutes and write up a table, e.g., 32 F = 0 C, 72 F = 22.2 C, 212 F = 100 C. If you did this, after a month or so you’d be able to think in Celsius.

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Celsius or Centigrade is easy. Water freezes at 0c. Boils at 100c. No weird numbers to remember.

Same with the rest of decimal system. Everything is nice multiples of 10.

Whether you use metric or imperial, remember that the metric system has won. Imperial aka British system has lost.

An inch is now defined to be exactly 0.0254 of a meter. There is no imperial system outside of the metric definition.

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So from the original post

  • Prunus domestica and probably others in section Prunus, 13-21C (16C), e.g. Japanese plum and E plum 13-21C

Its a werid combination of languages to comprehend. I did not cheat and look up the meaning. But based on your description peach/plum = prunus

Purnus domestica is a domestic peach/plum (Latin read it backwards?). I know of no such a tree unless grafted. However I do know there is an American plum, so I suspect that may be the right answer. Though i’m unsure who’s domestic domestica is referring too.

Also E plum I’ve never heard of an “E” plum before. Do you know what that is? I’ve seen a few people use this term here but I’ve never asked what it meant until now.

One last question, if you dont mind. If someone points at a tree and asks you what kind of tree is that. Are you going to respond maple or acer? And if they ask what kind of maple are you going to say boxelder or whatever the latin word is for boxelder? I’m asking because if I responded acer/whatever latin, I would most likely get a dumb look and that probably be the end of that discussion But if I responded maple/boxelder people would understand and we could carry on a conversation.

It seems to me this Linnaeus who ever he was back in 1750 just took common names and put them into a differnt language. Now I understand why I dont understand some of what is posted here. I appricate you bringing me this far.

Thanks again for your reply, hopefully I can be taught but right now the mix of terms and mix of lanugues is confusing at best.

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European Plum.

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In the Linnaean system, the bigger group (e.g., genus) is given before the smaller group (e.g., species). No doubt you’ve heard of humanity as “Homo sapiens” – literally, “Man wise.”

In many languages, adjectives come after the noun that they modify, at least most of the time. That’s true in so-called “Romance languages” derived from Latin (e.g., French, Spanish, Italian). You don’t read it “backwards” as in Hebrew. Rather, you read it forward – first you form a mental picture of the plum (prunus), next you modfy that picture to fit the descriptor (domestica). That seems more logical to me – How do I imagine “domestic” or “wise” or whatever before I have an object (i.e., plum, man . . .)?

<< If someone points at a tree and asks you what kind of tree is that. Are you going to respond maple or acer? >>

Depends what country I’m in. If I say “maple” to a friend in Spain, he’ll look at me confused. In Spain, they say “arce.” If I say “maple” to a friend in Germany, ditto. In Germany, they say “ahorn.” Bottom line, if I say “maple” i’ll be misunderstood in most of the world. If i’m talking to anyone familiar with trees, as on an international gardening forum, I have a better chance of being understood by a huge majority if I say “acer.”

I get your point. But IMO iIf we’re gonna Make America Great, we have to become less provincial.

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Many on here refer to plants with their latin names, so it’s strange to single out this post. Also, nobody is forcing the discussion onto anyone, so I’d suggest if you’re interested in the info, exercise some self-sufficiency. There are tools like Wikipedia which can give you the information you’re wondering about like Prunus domestica being the European plums/gages etc. and P. Persica being the peach. Pains me a little bit but you can dip just a toe into your own research here Prunus domestica - Wikipedia

Don’t be afraid to search other of the listed latin names if they escape you.

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I’m not nit picking so please dont think I am. I’m trying to understand.

In the context of the orginal post. It reads and I quote.

“* Prunus domestica and probably others in section Prunus, 13-21C (16C), e.g. Japanese plum and E plum 13-21C”

As you suggest (E plum = European plum) I have no reason to doubt you.

Thanks

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For some reason I find this discussion fascinating tonight.

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Botanical (Latin) names, are what’s used in science. And are really useful.

If you look up English scientific literature. You will still see Latin names for plants. There is no real need for translation. You will also encounter Latin names in scientific literature in other languages. The names aren’t really “Latin” their botanical names.

If you google. you will find loads of explanations. But

was the first hit for me. Might be worth a read.

ill summarize some of the most important parts.

In botanical (Latin) names.

You have at least 2 parts.

For example Prunus avium “burlat”

The first part, Prunus is the genus. The larger group this plant belongs though. (usually all plants in a genus evolved from the same ancestor)

The second part avium is the species. In this case your probably already familiar with it. Namely sweet cherry. Sometimes also called bird cherry or wild cherry or other names. (that’s why botanical names are so good, their less confusing)

the last part here “burlat” is the cultivar name.

Another name would be.

Prunus cerasus

This would be sour cherry.

Prunus domestica “victoria” would be plum and cultivar victoria. On this forum they often specify that this is an E plum or European plum. To differentiate it from

Prunus salicina Asian plums

Practically always plants in the same species can reproduce with each other. And are graft compatible.

Often plants in the same genus can be graft compatible and cross. But not always.

Sometimes plants are graft compatible from different genera (plural of genus) like Cydonia (quince) and Malus (apple)

The botanical names are actually the “correct” names. Their used in science. But also for import export. And in the EU at least for EU plant passport.

I much prefer people using the Botanical name over “common name”

@Malte
Thanks for the list!
The temperatures felt quite high to me. But than i realized you specified “optimal” temperature. Personally I’m most interested at what temperature callus formation almost stops. Since that’s what’s most important practically when grafting. Like the minimum and maximum temperature.

Sorry going off topic on the botanical names.
I appreciate you using them and the Celsius scale :slight_smile:

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What clarified it for me was this little fact: We all know a certain red-breasted bird that goes bob-bob-bobbin along as a “robin”, aka “turdus migratorius”.But in merry olde England a “robin” is "erithacus rubecula.

" In the 15th century, when it became popular to give human names to familiar species, the bird came to be known as robin redbreast, which was eventually shortened to robin.[5] As a given name, Robin is originally a smaller form of the name Robert. The term robin is also applied to some birds in other families with red or orange breasts. These include the American robin (Turdus migratorius, a thrush) and the Australasian robins of the family Petroicidae, the relationships of which are unclear.

Other older English names for the bird include ruddock and robinet. In American literature of the late 19th century, this robin was frequently called the English robin.[6]"

So if I’m talking to a Brit and use the term he’d likely think of the wrong bird,

So even though it might sound confusing and unnecessary, using the Latin name is actually clearer.

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Good point marknmt. Or distinguish currants (vitis vs. ribes) , or cinnamon, quince and such.

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