wondering if anyone could discuss this - what, in general, are the most common causes of grafts failing?
In my case I'd say dried out old scion wood, poorly fit union, wrong timing, too cold for proper callusing, allowed to dry out before union, or wrong technique for the situation.
If you have also had some grafting failure, welcome to the big club. What has been your grafting experience so far? The more details/clues that you provide, the less guessing/assuming from those hoping help you improve your report card.
I don't want to focus just on my own experiences but overall experiences of others in grafting.
I do think the apple scion I tried to graft onto my Enterprise tree was dried out.
I am also baffled why all of my scion wood didnt take, but wood from Geneva did. Very odd, I did nothing different between the samples.
I'll be reading this thread for potential reasons.
Sometimes I think I may have been using scion too small in diameter.
Because I have had so many failures and successes when trying to graft, I do not assume that anything I graft will automatically work. Hence, I take detailed notes of what was done for each graft and keep them in manila folders with each grafted fruiting plant involved. I try to follow what works most and avoid what seemed to be the reason for failure. Details matter. Copying what other grafters have been doing is so helpful.The citrus growers forum features some grafting tutorials by Joe Real that have really helped me. On youtube there are many to check out, some that would be much better if the explainer would present more details. Reading grafting info at university sites is helpful, but not as useful as video/audio of realtime grafting demos being done as the cameras roll. A rookie pilot told me that he has a prepared checklist that he goes through item-by-item when he is preparing to fly. Well, A prepared checklist for grafting is also useful. For instance, regarding the scions to be grafted: clipped when dormant?, thickness less than 1/2"? length long enough to have 3 or more healthy buds? waxed the freshly cut end to seal it before bagging? sanitized with bleachy water and rinsed before bagging if mold is visible? Freezer bag has moist paper towel inside to maintain high humidity? Temp. in lower fridge drawer between 40 and 45 degrees? Handled gently so as to preserve buds and not dislodge or break them off? Clipped from tree 1 to 2 months max before grafting? (depending on many things) Clipped waxed bottom off and fully hydrated scion by standing it upright in a glass with an inch of water with nutrients stirred in before grafting a day after the soaking started? Pre-wrapped the upper 80% of the scion in stretched Parafilm before going outside to graft? Let the scion warm up to room temp. while soaking? Pull the scion out of the water and let the waterlogged bottom dry for 20 minutes before shaving/carving the bottom end for the grafting while keeping it in the shade? Sprayed a couple squirts of water on the freshly shaved/carved bottom to keep it hydrated for a few minutes while preparing the rootstock branch (clip, carve, split, whatever)? Avoided touching the freshly cut bottom with dirty, oily, unsanitized fingers? Held the scion carefully without bumping or pushing against any buds while carving? etc., etc., etc. Boring and a waste of time for the veterans who do their grafting almost like a machine, but for a rookie pilot who wants to fly and return home to his family safely after the flight, very necessary..... This partial checklist does not include lots of other things that have life or death importance for a scion.
The time of grafting seems very important here. My apples and pears do best when grafted slightly before to shortly after first signs of growth while prunus needs to be grafted at least 2 weeks later.
Some say warmth is important for prunus, but it seems to me it may also be a matter of the tree being in more vigorous growth so wounds heal more quickly. Same reason you prune peach trees later to help avoid canker- no one ever suggests that it is the warmer weather that's in play there.
I lose more grafts after they take than before, especially grafts that are later to sprout out. Sometimes they look healthy but then die back later in the season even though the callous seems nicely healed. Sometimes J. plums grow well the entire first season but then don't make it through winter.
I believe leaf hoppers are sometimes to blame, sucking the life out of grafts because they tend to be the most tender growth on the tree after I've completed my normal round of insecticide sprays. It is difficult to keep them sprayed during the time they are vulnerable.
I believe my problem was poor cutting of graft unions...next year I need to use a much better knife (probably a razor blade). A couple took, but most failed.
At least with chip budding *summer*...its cambium not touching, not tight enough (rubber bands), drying out? .... Some grafts just fail. Matching size wood is also very important...not trying to stick some huge chip bud on a little branch, etc... I placed a bunch of successful chip buds on an apricot tree...then the whole tree died!!! yeah.
graft union should be more then an inch long. I don't meant total cut, but an in up/down the little tree once done. If doing tiny scions it would have to be less.
Don't watch random youtube videos and believe the person had a successful graft unless there is a followup video showing it. (watch Stephen Hayes for proper info) Take you knife to a good sharpening person (that you pay for) It should easily slice paper that you hold hanging in your other hand and then push the knife towards the floor. It should easily cut it. If you don't have a local, send it to omahaknife.com. that is where mine gets done.
If grafting to potted rootstock, not stressing the rootstock by getting it excessively watered by you or rain. This year I put all my pots 4 inches into the ground to let the earth wick away the extra water. I watered only when after sticking my finger into the soil and not hitting dampness until about 2". So only watered once and then very little.
I do mostly whip and tounge, with cleft as a backup for very different size match, or if I just can't cut right.... I do W&T even with not same size. just line up one side.... Grafted the week of April 21st. in Z 5.... wrapped with parafilm then rubber band... watered very minimally..
I marked my crappiest grafts, and even they are growing.
In regards to gathering scions. I don't do any of the extra handling mentioned above. I clip them, put them in a ziplock with a damp paper towel. Then to the fridge with a larger bag around the individual bags. They get moved around a bit in the fridge just like everything else in there. I still have apple and pear scions cut in Feb and they are still good. Given the chance I'll still use them and they will grow. (peach and some other won't keep like apple and pear)
This is a very useful discussion.
A person I know who does a lot of grafting has said he no longer uses the wet paper towel, just puts the scion into a ziplock in the fridge.
I think I would take all those extra steps myself, because my success at this hasn't been great, and anything to increase the odds.
I should have mentioned that I store scion wood in a cheap fridge with manual defrost- much less worry about drying out scions that way and then I can store fruit in same with same advantage.
I think doing everything by the book as Copingw/clay mentions is bound to improve odds, but I wouldn't store wood b/t 40 and 45. Wood needs to be stored as close to freezing as possible. Next year I plan to store wood in damp sawdust to try to keep the buds in the best condition.
Interesting you bring up Omaha knife. I received a high-end flashlight from them recently. Very good quality and the price was extraordinarily reasonable.
I have only learned recently that some species require moisture to preserve scionwood, while others do not. I acquired some Persian Walnut scionwood from the Nebraska Nutgrowers Assoc, and it had no moist paper towels or sponges. And it was in beautiful condition, unlike a lot of walnut wood I have received, bagged with moisture, but also with buds turning black. I read that walnut wood can even be kept on the fridge shelves without bagging! I have tried dry bagging with hickory, and it dries out quickly. It seems that apples and pawpaws also need moisture.
Timing seems to be the biggest issue. I wait until the budwood is only days away from pushing leaves. I'm having grafts take now in only a day or two. I'm also covering my grafts with plastic bags for the first couple of weeks along with wrapping the scion with Parafilm. Since I have been doing these three things, I'm having nearly 100% success.
In my opinion fruitnut nailed it dead on when he said "In my case I'd say dried out old scion wood, poorly fit union, wrong timing, too cold for proper callusing, allowed to dry out before union, or wrong technique for the situation."
I would add to that slightly from my own experience and say type of scion wood and rootstock are factors as well. Some scions are less compatible with some rootstocks. I know this is true because I will top work 3 scions on the same day of a variety on 4 different rootstock trees and on some they take 100% and some they fail 100%. I then go back and try another variety where they failed and they take 100%. I've had it happen to much to say its a coincidence. Taking risks is also a point of
failure and for me that means bench grafting small trees. If I try to graft the same year I plant I lose half or gained half depending on how you look at it. I know I wont get by with it half the time but when I do I gain a year but I lose half my time.
I find its more the stock/scion quality that causes my grafts to fail. This year I had two peach varieties that did not take; the trees I took them from were weak (from peach tree borer) and the scions didn't have enough vigor in them. I grafted them on 3-4 different stocks along with other varieties and the difference was clear: most of the peaches took off vigorously, and the weaker scion varieties mostly went nowhere. So, make sure you get very vigorous scions, and if they are weak cut them as late as possible to not reduce vigor.
Another graft failure I had was on a certain apricot I was trying to topwork. All the grafts started but then faded. The particular stock I was grafting on was send out its own buds like crazy, and I think it had decided it would rather feed existing wood than the new grafts. I was knocking off the new buds daily, but it kept putting them out. This is usually the biggest problem on persimmons, grafts there often fail due to competition from the stock. I had never had an apricot do this before. Anyway I don't know if I could have done anything about this apricot, but I probably saved some other grafts I have going by daily knocking off sprouts. Only when the graft is going well, 6" or more, can you relax.
Hman, Re: peach grafting in lab studies peaches do have a much more narrow callousing temperature than other common fruits. So, while vigor is very important, temperature also is.
Thanks Scott. Most of my stonefruit grafting is with plums.
I've never tried grafting to a rootstock, just topworking trees in the field.
I'd like to try chip budding some apples and pears this summer. Does this generally work as well as spring grafting?