Hot Callus Pipe DIY


You got two options. A temp. bed or rubbermaid. Keep them under a large deciduous tree or east side of the house, whatever options you can think of to transition them w/full success. You see the roots (unless they’re fully rooted in containers) aren’t going to like being planted with a new bud that’s going to be photosensitive “no-doubt.”

  1. You plant and see burn, most-likely. (if bareroot grafted)

If the scion has broken bud already, then there’s no question whatsoever you’ll need to “adapt” to full sun.

P.s. you got growth all over the rootstock needing rubbing off. I saw that first, ha-ha.


Thanks, learning everyday. Didnt know the little buds need rubbing off before sprouting. Been doing it after they break…





Things have been progressing on the hot callus pipe. This week marked the end of three weeks for most of the grafts. At this point, pear and cherry scions are budding, and I have begun potting them (I planned to pot all of them over the weekend, but the morels have been incredible - 15 lbs in two days). Here are a couple Benton, an Attika (aka Kordia), and a Black York.

The apricots have swollen buds but no green growth. All of my grafts were wrapped with temflex and parafilm M - except for the first one, which has only parafilm. When I was checking the moisture of the rootstock, there was a small hole in the parafilm.

I think it’s callus. It’s a whip and tongue, and I think you can see the callus running up the union.

Do you see what I’m talking about? So, at this point I have checked root moisture of the apricots and returned them to the pipe. Is this the correct thing to do?

I’m very happy :slightly_smiling_face::slightly_smiling_face: with the results I’m getting with the hot callus pipe. Hopefully these apricots will come along soon. :+1:


Looks like 100% callus. No need to return if so. pot it up, keep it free of frosts and when it starts warming up real good that’ll tell the scion bud(s) to grow. They need strong light then.

That hole if it isn’t a scion bud (which it does not appear to be) that’s rootstock growth that needs to be rubbed off. You need to rub off that on the above portion of the rootstocks and the root zones of the rootstocks. Both grow those thick white growths. From the roots, those will come up above the soil and try to make new trees. So rub them off too, everyone.



I’m going to invest in long tube socks and some sort of newspaper bag. Something real thin that requires one twist tie.

I’m going to cut a hole the size of a US Quarter at the toes front and slide the seedling thru and dip it in a bucket until satisfactory wetness. Then one twist-tie.

Ask your family and relatives and friends for their old, used, WHITE socks only.

That’s my opinion on the matter. That derives from do not use newspaper to remove the grease from your burgers cause ink bleeds in. Does that make sense to everyone?




Just reporting back on my results with the Callus Pipe. 68 persimmon grafts went into the pipe and so far 65 look good and are currently growing. The 3 that didn’t make it were all the same variety and I’m pretty sure the scion wasn’t viable when I grafted. So let’s call it 100% of viable scions took! Thanks for all the tips along the way @Barkslip.


Congrats Walter.

Have a super weekend, now. I got a new Fridge today : )



I’m going to report real quickly, instead of writing a novel.

The entire Genus Carya about 40% I’d guess. I have removed 90 grafts that I thought were good with b.walnuts mixed in there everyone, & I can conclude that nut tree reputation is true. They don’t graft easy.

Walnuts about 0%. I edited the first post so anyone just beginning will know. Walnuts do not like wet feet and I grafted bareroot-seedlings with roots wrapped in pretty wet towels. Is that the answer? Until someone tells me differently - why not think like that.

Persimmons - very easy.

pawpaws - very easy but I had aftercare losses. I’m down to 27 from 38 but these are very strong growing.

Last piece of information: whip & tongue was highly unsuccessful vs. V-cut tool on NUT-TREES. I’ll direct you to a link on that that very long w/plenty to learn I’m sure but the whole point is that within the first (I don’t know) 10-12 posts I show photos of a modification done in 5-minutes with a round rasp; the tool is only 20$ and replacement blades, 5$. It’s that simple. You buy them on alibaba or aliexpress and get replacement blades at the same time. Somewhere in those 240 posts are links, however, you’ll find what you need w/o searching that thread if you simply search those website.

Thanks everyone,



I have been working on a heat pipe as described here with the easy heat self regulating heat cable , using 3 calibrated precision thermometers I get somewhat different readings depending on where inside the foam I place the probe. 70-84F sometimes less , but when I shield the probe from any possible contact with the metal braid of the heat cable by wrapping it with masking tape or drilling out a piece of 5/16 scion and placing the probe inside it then placing it inside just as a graft might be I get low readings 67-72F, I think that is too low. I cant explain why the readings are considerable lower inside the drilled scion and with masking tape but it is. Perhaps the pipe is warm enough and good results can be had but next I am going to try and industrial PID digital controller with regular heat wires , not self regulating. I would like to hear others opinions on the efficacy of the Easy Heat shielded cable pipe method or other methods. Especially it they also built a higher temperature pipe and carefully achieved 75-82F which is considered by many the best range for callusing. This pipe I built does not achieve the ideal temperature.


Hi David,

You’re the only person getting lower than 80 F temps. I recall @zendog placing something over the cable which cooled his a bit, but you should be very happy with 70-84 it is my opinion.

One guy I know with a callus bench he built long ago that is all plumbed and has antifreeze running thru it and heated with a small water heater said to me, ‘that’s too hot…’ meaning my temps should be more around 72 I believe he said. I said, ‘well, it’s working great up there at or above 80.’

You don’t want to have the plant material touching the cable and I think that’s another reason @ zendog utilzed that metal conduit or whatever it may have been over his cable.

Honestly, I thought 72 F was too low. I just remember vividly this other guy commenting how much lower and in the 70’s he ran his hot pipe callus.

Btw, he’s grafting easy-easy stuff with the exception of Beech. Lots of Japanese maples & Ginkgoes which unite with simplicity. And he doesn’t know any other grafting technique than Veneer. So he’s grafting a difficult Genus with a less than ideal technique. Same with Hamamelis which I hear are not so easy. So he messes with witch-hazel, too.

Also, btw, since I know you and know you’re going to graft a ton of persimmons would be likely, you don’t need to be scientific past what the original design of this pipe does. You’ll get near 100% grafting persimmons. They’re so-so simple.

Best regards,



Dax mentioned my temps for my version of the design. Here is the link to where I show what I built (before sealing the ends):

And here was the post where I described the temps I measured inside the pipe:

I think the fact that I had about 100 slices for the bench grafts, all leaking a little warm air was part of it, but the main issue of my lower temps was probably the way I created a wood trough for the cable to lay in which meant the foam was only around 3/4 of the exterior. But I think the design did mean I could confidently push the grafts down close to the wire without fear of hitting the wire which may have been a good thing. I would also suggest that possibly there is some variation in the manufacture of these heating wires, so that might impact it as well. I know lower end digital thermometers, my aquarium heaters and other relatively inexpensive stuff can vary quite a bit.

Dax mentions you are grafting persimmons and that was primarily what I grafted last year. With the pipe and the temps I got with it, I basically had 100% takes on my persimmons. I’m discounting 3 grafts from that result which never showed any life and I’m pretty sure that scion was basically DOA so never had a chance. So I expect you’ll get good results with your pipe as it is.

Good luck with your project and let us know how it goes and if you make any changes.


Thanks, Walter.



I’ll preface my post by saying I just discovered this thread and am still working through it. I have one of those “pipe freeze cables” available at work that seems to be similar to what I’ve seen so far in the thread. I also just saw this heated blanket:

Would it make sense to put a blanket like this underneath grafts in a long Rubbermaid style bin for a smaller amount of material, and somehow seal the container? Or would you want to keep airflow and actually drill holes in the container? Or am I completely off base with my train of thought…


The critical part of the callous pipe as I understand it is isolating the heat to the graft union and not applying heat to the rest of the rootstock or scion. Last year I wound up with some buds (motsly from rootstock but a few from scion) in the pipe and many of those pushed and started growing before it was time to take them off the pipe. You really want to keep the buds from pushing until you plant them out as much as possible, although pushing buds on the scion you can deal with by very slowly introducing the plant to light.

This year I will be doing a bunch of chip budding and I’m not sure if that will work in the pipe, since the small size of the scion means that it basically needs to be in the pipe and may very well wake up early.


I see. That makes a whole lot of sense. I’ll be reading through this thread and probably trying this technique out on the apples currently heading my way. It’s so cool to learn new things from this forum every day.


I’ve had good success with chip buds (persimmon) in the hot callus pipe. They did start pushing out prematurely but it was around mid April already and time for the rootstock to wake up.


@zendog That’s great advice from Ramv. The chances of a chip bud awakening is probably 90% if left inside the pipe for 3-weeks. And the problem is that unless you check on them every day or couple of days and you waited a week, the chip bud may have grown an inch up to 3" I’ve had (buds) grow that were inside the pipe.

@disc4tw That’s everything you need to know from zendog. Your first and second options for grafts that aren’t chip buds that you graft on the pipe is to remove the graft from and put each in a refrigerator. Never a freezer. The second option is for people with basements that aren’t heated, to put the grafts in as much darkness and the coolest corner of your basement holding them as dormant for as long as you can. But remember if they wake up they need as much light as you can give them pronto. If they wake up with white growth and you didn’t catch it then you need to be getting them under a shop light. It takes a good 3-4 weeks until you can give them strong sunlight. That growth has to turn to dark green and that’s when they’re ready to be acclimated to the outdoors (hardened off) which hardening off of course takes 7-10 to 14-days to do properly. So there’s a lot to think about. Things can change real quickly and you have to ask questions if you’re unsure.


I have a question or two- I am looking at heat cables on HomeDeot’s site. They carry both FrostKing and M-D Building products in different lengths- which say that cable turns on at 38F and off at 45-50F. How do these work as cables for this hot callus pipe? Looks like the FrostKing has been used here, based on photos. I would like to set something up for apple and pear grafts, doing them in the basement which stays at 60-62F through the winter. Air temp, I think floor temp is less.


Remember those are way too low of temps.

And, truthfully, for anyone trying to reinvent the wheel, have fun… I don’t diss ya at all. I just don’t understand the need to take something that works perfectly/perfectly fine & try to find some other way to do it.

It’s all in the first post, everything to buy, & how to build it, and the aftercare even… I haven’t spared a thought.