I was just thinking.

is it true that the growing tip of the stock is best to graft to because

1: the vascular tissue is new and soft and

2: there are more Auxins (?) in the growing tip which assist the scion to 'take'

if the above is true...

if i want to graft to middle of a stock I could cut it - wait to heal & wait for first signs of growth (pupping) which would indicate lots of chemical goodies auxins etc. of course the vascular tissue is still going to old and tough.

is the auxin theory true?
would love to hear your thoughts.... :geek:

generally grafting to the new growing material is recommended because of the reasons you stated and consequently you then get the better scion growth.

but just a thought.. by removing the growing tip of the stock plant and letting it callous you are breaking apical dominance and stimulating offset production from the areoles near the wound in the absence of auxin. When you remove the offsets and graft a scion onto it would apical dominance be reinstated? as you say the vascular tissue is going to be tough and old anyway and the scion may be more reluctant to take.

IME it really doesn't work that well and the scion gets rejected by the stock. The stock will favour growing new pups rather than transporting energy into a scion.

Not saying don't try it, but think you will find that a nice healthy and actively growing tip will work best for a grafting stock. I once read that you should only use the best quality stocks for grafting. There is a lot of sense in that I think.

I have a little trick that works well. I have done this on T.Spach and had great sucess.

Take a youngish section say about 1ft long and 5 or 6ish cm diameter and cut it about 6-8cm from the ground. Now do as you please wtih the top, you can cut it in to sections about 6-8cm and use this method over and over again.

Allow the plant to callous and produce a pup (only one, if others cut them off). Once the pup is 5-8cm tall I cut to pup and graft to it. I then repot the spach so the bottom original section is completely covered with potting media and centre the new pup above the soil giving it an appearance of there only being a single section/plant.

The scions will take fairly easily and growth is about the same if not a little faster. I have not no problems with the bottom section rotting, it will just harden over time.

i am not sure about auxins helping the healing aspect of things..perhaps??? but if you cut your cactus, or plant for that matter, the auxins are going to concentrate elsewhere to feed a growing point....this could be a pup or a scion. i would *guess* that with species like T. pachanoi, which often pup from the base, that if cut and left for a period of time the auxins would be concentrated at the base of the plant.

but you are right in that new growth, already being hormone filled, will grow much faster than older growth. that said even 6" thick 4 year old woody columnar tissue is graftable.....but success is low and growth even lower. i think it has to do with the flexibility of attachability of new soft tissue, rather than growth hormones (excuse the english lol). even then, old growth can still be somewhat soft and totally graftable. "this years growth" is just a quick guidline, but is by no means the rule.