Before or after petal fall?
Same for Cherries?
The main thing to time is the weather - you need several days with highs in the 70's/80's after you graft. I have done peaches before or after petal fall depending on temps. This year I did them all during bloom but before petal fall.
I wish there was more research on this subject. They say trees callous faster during warm weather but I've never seen research that really shows how much it has to do with the actual growing state of the trees, or with the air temps- they are very closely related.
What I know is that trees that are growing fast in general get much better graft results. If you try grafting a recently transplanted tree, grafts will be sluggish at best and take % will be down greatly.
I think the reason grafts may do better preceding warm weather is that the tree is growing faster, so if you wait until stone fruit actually leafs out you are grafting during fastest growth and sunny days will likely be warmer than earlier in the season.
Maybe Scott can try some similar grafts a couple weeks later and get a comparison this year with peaches and plums. I got plum wood.
I think it's more the temps, not the actual growing state of the trees.
The reason I say this is supposedly stone fruits can be successfully grafted and callused when fully dormant. Although it wasn't his own idea, Bob Purvis once showed me a drawing of a contraption he was making to do that. Basically a piece of pvc pipe with some heat source inside which heats the graft site of a roostock by way of a slot cut in the pipe. The graft site of the tree is laid over the slot and calluses the graft site. All this is done in the garage in the middle of winter with the tree fully dormant.
Another reason I think temp is the more critical factor is that I've had very good luck budding peach trees around the 1st of September. The trees are not really growing much at that point but the grafts will heal if the temperature is right.
Last summer, I budded about 20 Clayton peaches in mid June, from some wood Scott sent me. At that time I also budded other peaches from some wood of my own. The temps were near or above 100F for many days and not a single graft took.
I budded again (from some of my own wood) around the first of Sept. when the temperatures didn't get above 90F and had a high percentage of takes (8 Redhaven, 9 O'Henry, 1 Encore, 1 Johnboy).
Scott, out of the kindness of his heart, sent me some more Clayton wood in Sept., but it was just too late. It arrived the 3rd week in Sept. and I budded it on Sept. 18th. Temps were just too cool. As I recall, it barely got to 70 for the highs. I budded about 10 rootstocks to Clayton, plus some others from wood of my own, and once again, not a single one took.
Last year was my third year doing late summer budding and the results have been the same every year regarding high temps. Good results with temps not above 90F for the high, but complete failure for temps of 95+F.
Last year was the first year I tried to late summer bud in cooler temps of 70F for the high, but it didn't work.
This year I'm going to try to spring graft with dormant scionwood. You'd mentioned you had good success last year by waiting until the peach is fully leafed out, so I'm going to try that this year. I've tried spring grafting peaches in the past, but never had any success. Looking back, I think I always grafted when it was too cool. I was always anxious to get started and had problems keeping the scionwood from sprouting in the refrigerator. This year I've kept the scionwood right at freezing so it won't sprout.
Olpea, I have noticed several similar temperature correlations. At first I thought it could never be too hot but I had one of those high 90's streaks overlapping with my usual spring grafting window and nearly all of the peaches failed. I also had some late fall buds from last fall all fail. This spring I grafted when it was a little on the hot side, it was high 90 one day, but it quickly got down into the 80's/70's. Most of the grafts are moving now, two weeks later.
There have been some studies of optimal callous temperatures of different fruits which show peaches have a narrow temperature they like to callous in, so there is a scientific basis.
4-6 I bench grafted 10 tart cherries onto Krymsk 5 stock and planted within a couple days. COLD snap afterwards, and it has been bouncing between 70 and 25 ever since. Buds look like they are swelling.
4-13 Bench grafted 25 tart cherries onto Mahaleb stock, and "planted" them in buckets under the house. 50F, the buds are green tip on these now, and I might have to wait until after the last freeze to actually plant them. May 10th??
Time will tell on both of these samples. I will try to update if I see anything interesting.
I had very good luck grafting stone fruits when the day time temp around 70's for a period of a week or so. I used barkgraft exclusively. Just make sure you do a little side cut on both sides of your splice and taped it well to prevent any rain water entering the union or that graft will turn to rot or dry out. I got all 6 grafts took last spring. Good luck.
OK, you've sold me.
No wait, not quite. It is not just a matter of callous. Many of my failed grafts callous well and start to grow and then die. Even though they seem healed they dry out and die. I do get better growth from my earliest apple and pear grafts.
How much a graft grows seems directly related to how soon in the season it leafs out and grafts that don't grow vigorously often fail, even if they callous so, for me, it's back to the drawing board.
However with stonefruit, I will rethink this as I'm talking about grafting later being better for them. Of course many years it isn't until they leaf out that you get your first reliably warm weather as is the case this year, apparently.
You do want to aim for the earliest feasible temperature window, if nothing else to get the best growth in that season. This year my apples were not much past silver tip and the peaches were barely showing any leaf when I grafted, because it was cold for very long and then a week of very warm came along and I jumped on it.
Well, now I'm trying to time grafting of stone fruit here and mostly cool weather lies ahead- nothing out of the '60's besides maybe tomorrow is predicted in next two weeks. J. Plums are about half open blooms. Early flowering peaches same.
What do you think, Scott, should I wait what may be another two weeks or more for actually warm weather?
I would definitely wait for 70's at least. Every year a good window has come along for me. If I'm not sure if a window is going to be a really good one I will do only one of each variety in the first window, then wait for the next one and double them up. In fact I did two windows of peaches this year, after the big heat passed through I did backups in a bit lower temp window.
Its good to read this I am going to graft peach plum, and cherry this Spring. I think I will wait till we get 70 deg weather forecasted, probably the end of May the way this Spring has been.
Johnny, plum and cherry are more flexible than peach so if you have a lot to do you can do those in the 60's highs days for cherries and even 50's for plums. Definitely wait on the peaches.
By the way I don't see that I mentioned it above but I always do backups on peaches. Usually I do two grafts in two windows for a total of four of each variety. Peaches seem to be more flakey than other things and this way I always get at least one take on each variety. This year since my first window was so early I am going to wait to do more grafts on the few things that are not pushing, probably this weekend I will do any needed re-grafting. Also, peaches always get complete coverage of scion to prevent drying-out, as well as aluminum foil sun protectant on south side if its in higher 80s on up.
Thanks for the heads up. I will cover them up, and hopefully if the weather will cooperate I will be grafting my plums. I just want to swap scions on my Asian plums to help them pollenate. They might be fine but I figure what the heck.