Hot Callus Pipe DIY


3-days off to relax. It’s been a pretty long run. I built the beginning of the second bench on Sat. This one will be completely different from the other (naturally) because I’m beginning from scratch.

Best regards, ya’all.



today’s project graft wowza to carmine jewel seedlings and set up hot callus…

was tricky because scion material was much smaller than rootstock! hopefully a few take

roots on these seedlings are impressive, all were larger than above ground portion…

from 2 small sticks i managed 10 grafts.

instead of removing roots and causing more stress i put them in deep pots.

leaving them on ground to keep cold that is still near freezing. hot pipe seems to work well. when set at 70f it turns on at 69 and power goes of at 70f and temp quits climbing at 75f. sensor is in contact with aluminum bar inside insulation as are the grafts.

covered with synthetic blankets with white plastic over the top and held down with hardwood stakes…

im not sure what temp is ideal to heal the wounds. let me know if i should lower it please…


Very cool. If you Google temperature hot callus pipe they give you a range. All I know is that extra warm works very-well. People using my friend Ryan’s whole system and set-up are at 83-84 I think. That’s the end of the range from what I remember.

Someone asked me what the best temps are for certain things. I don’t have a clue. I need to find someone who knows or, find a book.



do you think that i should maybe wait till roots start to wake with such small grafted pieces? several don’t even come out opposite side of the pipe!


Well that’s what I was looking at after I posted, wondering if you have the buds outside the pipe. You can but it’s not advisable to have them inside the foam. They can and likely will break bud prior to the union callusing, Derek.

What I do is tip them at severe angles to get the bud even if 1 mm anywhere outside of the pipe I feel like the heat still radiates beneath at the union, upward.

That’s how I do it.



checked the pipe, no way to move buds out. increased temp to 73 which should provide heat from 72 to 78f. thinking maybe buds won’t break for lack of fluid pressure until graft heals, hard to know though… im gonna remove some early i think, maybe after 7 to 10 days…


My thinking is the cherry (Cornelian) or whatever it is, I just know that stuff is dense as hell. That’s gonna take 3-weeks.

I think what you’re doing is brilliant-Derek in grafting onto root (and everyone knows the suckering is never gonna be the cultivar…) it’s the same as pawpaw.



hot callus cherry aborted…


Bench-grafting stone fruits in the spring can be done, but the requirements for success are more rigorous than are those for apples or pears. In late January I discussed with Dr. Brian Smith, the stone-fruit breeder at the University of Wisconsin at River Falls, what the requirements are for bench-grafting cherries. Based on his experience, he said that cherry rootstocks should not be grafted when totally dormant, but when there is about ¼ to ½” of new growth coming out of the top of the rootstock. Possibly because the buds and leaves of cherry are large and use a lot of water, he recommends keeping freshly grafted cherry rootstocks at a temperature of 55 to 60F in a high-humidity environment. At those temperatures, callus tissue will form but the scion buds will be slower to break dormancy


Thanks for the post, I saw this on the web site. But I dont think he is explicitly saying the cherry will not work with hot callusing.
As I read it, as long as the root zone is getting enough moisture and the graft union is sealed with parafilm or similar, there is enough moisture/high humidity at the graft zone.

The usual advice for persimmon is that there is atleast 1" of growth before grafting but I’ve had far better success grafting to dormant rootstock using the hot callusing approach. I suspect it is the same with cherry and people haven’t tried it. The only difference I think is that the graft temperature has to be lower for Cherries.


Amazing how fast chestnuts give results on the pipe - a week tops.

Mulberries aren’t too far behind, around 14 days. Their callis tends to be more subtle and blend with the colour of the wood.

Walnuts have been vexing so far, though. The bleeding is a real tough problem, even for dormant, cold stock. I might try sweating a few and banana/four flap grafting.

Another occasional issue is the rapidly growing callous busting through the parafilm so things get a little dry in there. I guess one solution is electrical taping the whole union, but that makes my peeking tendencies frustrated.


@TheDerek - those are two different worlds being discussed. Keep your plants on the pipe. Ram said it right.

@DerickGreenly - I don’t take my grafts apart and don’t use parafilm so can’t see thru. Never saw a single bleed, yet. All of us if we see how “juicy green” certain Genus’ and/or Genus and species are. Sometimes it’s just because of the wood being juvenile. Other times it’s because that’s how that Genus/species always is. When we notice how much green there is to be had or should we see moisture and along with green, that’s “juicy”. It’s like a prime rib slice of meat. Those are always going to “buddy up” (a grafting term) faster & easier.

When I graft nut trees, the wood looks dry and looks dull in color & the ribbon of cambium is minute/very thin. That’s why (I have come to believe) nut trees do not graft as successfully.

A hot callus pipe or hot outside temperatures; or really turning up the heat in a greenhouse (is necessary) to successfully graft nut trees. The other exception is a very strong root-system and grafting technique, used. “Four flap” and Bark graft are the most commonly used. For some reason when a tree with an inch or inch and a half caliper (doesn’t matter if nut or fruit or ornamental but has to be deciduous (not coniferous) ) has all that staying root-power then, you can graft when temps are still cool. Cool means in the 50’s and low 60’s for the most part and anything below 70 in Fahrenheit.

Grafting commences when the buds are at plump swell or you might even graft if the scales are split open enough to show green coloration. But plump bud swell is something I like, personally, and the unfurling of leaves at any stage of leaf-length. Remember, I’m discussing 1" caliper plus trees in the landscape or the equivalent in a container. The container either being grafted outdoors (1" plus caliper) or inside a greenhouse at the cool or warm temperature phases.



Great. Im grafting dormant heartnut on bareroot nigra with a v-grafter and hot pipe at 26 degrees and having only spotty success with that species alone. Maybe a touch more heat? Or just way more attempts.


Search I did yesterday suggested that some nuts like up to 85f when being grafted… Im no expert tho.

Ok so wheres what I did, I pulled 4 grafts off completely and IM going to leave them in a shaded area outside to do whatever plants do. 6 I left in and I turned down temperature to 68f, so it should stay in the range of 67 to 73f. That is as low as my controller will go. Ill leave it for a couple weeks and check to see whats going on. Ive had success callusing hardwood cuttings from canadian cherries over lower temperatures with bottom heat, so maybe this will be the same.

If anyone knows for sure this is a bad idea, speak now or forever hold your pieces…


Here’s what I could find on it:

Page 502 on the printed pages or 39 of the PDF. I have the book Plant Propagation Principles and Practices and it looks like it’s the same.

I also tried searching the reference, but just came up with this:


I’m going to try bench grafting some peaches. I want to plant them in a nursery bed right away instead of in pots. What’s a good way to use this and keep the roots healthy? Can I bag them with some peat or moist pine shavings or will pots be the best method for success?


You can bag them but I’d use something sterile for sure.

Since I started 2.5 months ago I wrapped all my bareroot in pretty damp paper towels. Anything to keep the roots moist and cool while callusing is sufficient.

Wash (any) mud off if you ever use paper towels. If the roots grow thru the paper towels then plant it that way w/the paper towels in-tact.

And @DerickGreenly, I can’t answer for you. I simply cannot know everything that’s going on (for you.)
Turn it up, yes.



I take off all my grafting rubber bands the middle of July, all at once. I look at the unions and determine which ones could use another rubber retained and leave off all that look (and feel) solid. You all will see scions that grew (from the reserve sugars & starches in the wood) but when you remove the rubber , you will see the scion fall right off. You’re going to see grafts where one side callused and the other diden’ & that’s a good time to put a new rubber back on.

You should all be thinking about staking.

You’re going to see a lot of pressed inward bark from wrapping too-tightly. You’ll have to learn to “literally” hold/press your FLAPS together (before AND as you wind the budding strip…) using your hands and turning the “pieces” “The Union” in your hands and between your fingers to hold them FLAPS snugly together and then bring the budding strip in place - to hold it _now between your fingers_that are again holding the whole thing together. It’s a wrap comfortably and slowly routine as you continuously look down and from the sides to put the bud strip on firm enough, only.

That should make a lot of sense to some of you and others will catch-up.

What I like about the v or saddle graft is the union has so much added (whip & tongue also /or/ any graft that lines up the cambium on both sides / also known as exact matches for a cleft. A lot of the time we might get one side of a cleft to line up. Every time you look at a whip and tonge, v, you get extra stitches going “across” the entire union. I look at that like stitches on a sewing machine. You can turn the dial to make a stronger stitch.

I’ve given everyone a chance to become a nursery if you want to learn the trade. You can work “off the grid” (with or w/o a tool : ) @SkillCult ) Btw, Mr. Skillcut I modified the first 135 grafts using whip and tongue that is going to either be a crash or complete success. If successful, some of the most-interesting graft unions are going to be seen as far as I know, for the first time. It means nothing but the appearances will be “unusually awesome” to look at and all thanks, to this callus pipe - system.

Have a great one, Steven, et. al.



I wasnt meaning to press you for answers; merely to report my last few frontiers of difficulty on what is otherwise a world of limitless potential.


Here’s some grafts I have going using my zenport grafting tool. Pear and Apple. I’ve been using mostly Bud118 and OHxF97 rootstocks for all of my trees. I was going to try some whip and tongue grafts, but I almost turned my thumb into a whip when making a tongue on one so I’m gonna stick to the zenport tool for a bit. I may practice some more on scionwood.

The zenport is still making razor sharp cuts. I did get a Worksharp Ken Onion knife sharpener, so I’ll likely resharpen if I notice it getting dull or after completion of all my bench grafts. Bagging the rootstocks like this, wrapped in damp paper towel and placing the graft union in the pipe for 21 days gave me 95+% success last year. Hoping for the same result. BTW I appreciate those of you who have provided me quality scionwood. As my trees mature, I’ll have more to offer and trade.


Wow. Thank you for all the great information!