I have a Mexican plum tree, prunus mexicana, growing wild on my property that I’m wanting to use as a rootstock for peaches. It’s thriving in my shallow calcareous soil, without any irrigation. What I was planning on doing is grafting a bunch of the 3/4” diameter branches with peach varieties that I already have this coming spring, and once the grafts look like they have taken going straight into air layering them. I’ve seen some info on another post about managing the difficulties of air layering stone fruit, but I wanted to make this post for the sake of documenting progress, successes, and failures, as well as opening it up for suggestions by wiser and more experienced growers, which is pretty much everyone considering how new I am to all of this.
Like your icon pic!
Actually, assuming your native plum is mature and you have multiple opportunities, I would suggest trying two methods. I think both may work for you and you may end up with extra peach trees.
As you mentioned: air layer the branch as soon as you get a peach graft take. Most native prunus easily air layer as long as you take advantage of the early growing season. I would probably do the air layer first to be certain the limb is tied up in a stable manner, then graft the tip about when the rootstock buds are swelling and temps are well above 70F. This sequence would avoid disturbing the graft union during the critical 3-4 weeks of callousing period, while using the most productive growth period for rooting to occur. Even if graft fails you would have a new rootstock to graft again!
Take cuttings now, sharpen the base end of each 10” cutting, scratch the bark of about 70% of the base to expose but not remove the green cambium. Treat with either a powder or homemade willow hormone and plant the cutting in a sunny location in a sandy loam compost mixture leaving only a couple buds above the soil mixture. Keep the growing bed moist well drained and covered with a clear plastic until buds break. Once temps are up above 70F, and buds are opening, remove the cover to avoid over heating but keep bed moist daily.
The Roots on these will be too fragile to try grafting this season, unless you can plant them in pots and graft later during the growing season. But they will be excellent for later grafting.
Good luck and let me know if you would trade for some of my native plum varieties
Optimum Callusing temperatures of Fruit and Nut trees
Mr. Dennis, thank you very much for that timely advice. Yes, I would certainly be happy to mail you some cuttings of a couple of native prunus species. We have wild prunus mexicana and prunus augustifolia (sp?) all over.
Okay, since the tree is both large and biforkated at about 2’ high, I will do this:
cut off half the tree for cuttings, and to give me a place to top work a peach onto in the spring.
start my air layering on the other side of the tree, in hopes of still having time to spring graft on the peaches.
I suppose if the air layering takes so long and it’s late for spring grafting the I could try summer chip grafting. Probably hard to do up in the air, but whatever.
For the air layers, do you suggest fully girdling the branch or only partially?
Do not try to girdle but simply lightly scrape of the outer bark to expose the green cambium layer on 80-90% of the length of the airlayer. My air layers worked best when I used a plastic bottle to enclose moist spagnum moss around the exposed branch and seal it very well with tape to assure no moisture loss. Also use aluminum foil to cover the bottle to protect from direct sunlight. I will pm you my address
Here’s an update. My Mexican plum tree is in full bloom, but hasn’t started leafing out so I set some air layers on last years growth. I put up 5 yesterday, but I’m planning on putting up another 5 once it starts to leaf out. I’m hopeful that both sets produce some good results. The daily temps are fluctuating from 45-75.
They are about the size of a quarter, pinkish purple when ripe. I’ve had some that were too tart to enjoy, and I’ve had others that were pretty decent. The size plus the large seed make them better for preserves if anything.