Now the weather is finally cooling, many of us can begin experimenting with wrapping cuttings. There are a few questions which have been presented to me, so I'll attempt to answer them here, with all I've discovered here in my climate.
1. The best wood is that which has over wintered, hardened off and stored enough nutrition to break dormancy in spring. Wrapping cuttings which are fresh flowering stems hasn't been successful in many cases based upon those who have written me and in my own attempts. The wood has to contain enough stored food to permit it to callus, form roots and begin life as an independent plant. Stems grown this year, whether it has flowered or not, have, in most experiences reported to me as well as my own, proved too soft and failed. Wood grown last year and carried over winter is the best for this method.
2. It appears the most beneficial temperature range to hold the wrapped cuttings under is between the low fifties to mid to upper sixties degrees F. Too high and they won't callus, and may either dry out quickly or even rot. Too low and they preserve like produce in your vegetable crisper, without callusing.
3. From experiences reported to me and my own, it appears if the cuttings aren't going to callus within the initial two weeks of being wrapped, leaving them longer reduces the probability they are going to callus at all. Of course, you may experiment, leaving them as long as you wish, but from reports and observations, two weeks is the optimum time, at the optimum temperatures.
4. You MUST remove all the foliage from all of the cuttings, PERIOD. Leaves wrapped in the damp paper can both cause the cuttings to dry out as well as rot. You are dealing with hard wood cuttings. These are best dealt with bare, no foliage left on them.
5. You may remove the prickles if you wish. You don't have to remove the prickles if you don't want to. Removing them, if possible, can expose more cambium layer, which can then callus and eventually form roots. Removing them, if possible, can also make handling the cuttings nicer and prevent the damp paper from being damaged and hanging on to the cuttings when removing them from the wraps. This part is completely up to you.
6. You do not have to treat the entire cutting with rooting hormone. You treat the bottom end, the end you expect to form roots. Other exposed sections of cambium can form callus and roots along the cutting. You may, if you wish, cut the cutting up to make use of the places it is forming roots, or, you may simply plant it as deeply as you wish to form roots anywhere it wants. Again, up to you.
7. The length of cutting is up to you. I intend to experiment this winter/spring using one and two bud long cuttings to see just how much is necessary for the method to work. I've already demonstrated you can root whips up to nearly four feet long of suitable types for standard trunks. I also want to experiment with my VI Fortuniana to see if precallusing them can make the bloody things root more easily. If you're intending on rooting stocks for budding this summer, this may give you a leg-up getting your material ready.