There have been many threads here on when to graft, but one thing I would like is a list based on how far along the leaves/buds are on the stock. The temperatures are also important but that information is more well-known; I’ll include it here anyway (highs for the day are what is listed). Note that temps are callus temps and do not take into account the fact that the sun may be warming up the graft unions well beyond these ranges. The sun can add 20F to the air temperature and will significantly change the rate of callus. Also remember that grafts also will callus at night, it is having as many hours as possible in the ideal callus window that matters.
Anyway here is my current thought… I will edit this based on comments. These timings are not uniform across all climates unfortunately, but hopefully close enough that we can share data.
-
Apples - 45-70F. Tight cluster is optimal, up to 1" leaves still excellent. You want to graft apples on the early side compared to most things as there is a big spring flush of growth that early grafts will get and late grafts will miss. There is a fairly wide window of opportunity, but don’t graft before major bud swell and don’t bother once it is hot.
-
Pear - similar to apples and generally easier to get takes so more leeway.
-
Peach - 65F-80F. 1-2" leaves seems to be the point when I have had the best luck on average over the years. 1/2" to 3" can work depending on how the temperatures are, peaches are more grafted based on temps than on growth because they are so temperature-sensitive for callusing. The above range is the callus window but don’t forget the sun effects, and shield with aluminum foil if it is getting sunny and temps are in the 70’s or higher.
-
Apricot - 60F-80F. Similar to peach, also almost as difficult.
-
Cherry - 55F-70F. I am a bit rusty having not grafted cherries in a few years. I think it was 1/2"-2"?
-
J Plum - 55F-70F. Graft at 1/2"-2" I would say; they are easier than peaches but harder than E plums.
-
E Plum - 55F-65F. 1/2"-2". Similar to J plums but easier to get takes.
-
Grape - 80-90F. Around 6" of growth is needed before it is warm enough to graft grapes. Or wait til 1’ or so and graft to the base of the new green shoot. I have had best luck with this approach and do all my grapes this way now.
-
Kiwi - 60-70F. 1-2" leaves. They seem to do better on the early as opposed to later side, the plants accept grafts more willingly when not too late.
-
Persimmon - 70-80F. Persimmons bud out relatively later; I would guess my leaves are usually around 1/2"-1" long when the temps have warmed up enough to graft. The ideal window is a bit hard to hit as you want it to be warm but when the plant gets too far along grafts seem to be rejected. If the buds are small the bark may not be slipping yet, persimmons are a bit delayed on getting the bark slipping compared to other trees.
-
Pawpaw - 55-75F? Pawpaws are usually pretty easy as long as you are not really late… 1"-3" leaves should work.
-
Jujube - 60-80F. Jujubes should have little nubby growth of at least 1/4".
I haven’t grafted enough figs or nuts to have anything more than a guess.
