It is not too uncommon to end up with scions that are sprouting before they are grafted out. If you graft for very long, you will encounter this problem, and probably sooner than later, as it is not entirely avoidable. For example, I will end up grafting dozens of them this year and do many years. Sometimes by my own fault for not harvesting scion soon enough, or not grafting early enough, sometimes for reasons beyond my control.
The problem may be very obvious, with significant green showing on the buds, and other times, the buds are just swelling out and maybe showing just a little bit of green or white. While buds that start pushing on a scion are not ideal, they are not necessarily a death sentence. This article will look at some strategies that may increase survival rates on sticks that have broken dormancy.
These buds are not showing green or white yet, but they are definitely swollen, so they will soon. There is still a lot of hope for grafting sticks with buds like this, but it helps to take some steps to improve chances success.
Even if you harvest good dormant scions, sometimes you’ll get some that just really want to grow early and may begin to sprout in the refrigerator. Crab apples and apples hybridized with crab genetics can be especially early bloomers and will not uncommonly start pushing in refrigeration. Other times they may get warm during transport and want to wake up. Recently my usual mail carrier quit and didn’t pick up the outgoing packages of scions I dropped off, which I didn’t find out til 4 days late. At the same time, the huge bag of rare scions Chris Homanics sent me was sent back to the post office awaiting pick up in a heated building. Stuff happens.
You may also be delayed in cutting scions or find something late in the season that you really want to graft right away. In that case, you have more leeway about what to choose from the tree. You can look for shoots that have dormant buds. Often small dormant buds are abundant at the bases of the previous year’s growth, between one year’s growth and the next, or on older shoots.
One time I got some scions very late in the season. And then I put them in the fridge and didn’t graft them. Then I didn’t graft them some more. Finally, on a day in early July, during a heat wave, over 100º F for several days, I grafted them out. Some were showing green and pushing out, but quite a few still survived. Don’t give up on scions too easily. They sometimes heal quickly and start receiving resources from the stock to grow and survive on. Just graft them and see if it works.
If the scion is showing green, I recommend leaving it long, but removing some of the buds. Here is the rationale, which I’m not claiming is correct, it just makes sense to me. The scion needs resources, food, minerals and water. In general, what seems more likely to survive, a 4 inch scion, or a 1 inch scion? A 4 inch scion has more resources, more nutriment, more water. On the other hand it also has more surface area to lose water, but my money is going to be on longer scions having greater survival potential. But, in order to increase survival, sometimes we need to balance the amount of growth with the amount of wood, so lets talk about that.
When you transplant a plant, it generally pays to attend to the ratio of top to root. If the roots are damaged or cut away, or if for any other reason there is very little root to pump water and nutrients out of the soil and into the top, the leaves and shoots should be reduced so that the roots can keep up with the leaf area. If I cut most of the roots from a tree, but leave the top alone, all those shoots sprout and try to grow and the roots just can’t support all of that growth losing water every day.
I see scions in the same way. If there is plenty of time for the graft to heal, then it has access to the resources that the root system of the stock provides. If however, it is slow to heal, or the shoots on the scion come out too fast, or there are too many shoots and leaves early in the season, then we have a problem. Those early shoots will suck the scion dry and it may fail. Presumably, the more green a bud is showing, the faster it is losing water, and the sooner it will make leaves.
A long scion also has more food- more minerals, more carbohydrate. So for those reasons, if a scion has 6 buds and I would normally framework it onto a tree with all 6 buds, but some are sprouting, I’ll remove most down to as little as two, or even one in extreme cases, and cut the scion just above the top most remaining bud.
This late harvested Chestnut Crab scion has some very sprouted out buds. But the remaining buds look pretty good. Some scions will sprout at the base first, some at the tip, and some are a bit random. This one has good sized very dormant bud, C near the top, and a few more tucked around just below the tip from small to tiny. If I wanted a long scion for frameworking, I would cut just the tip off, leaving some if the small dormant buds below it as well as bud C, remove A & B and leave the rest. If I were bench grafting onto small stocks to make new trees, or if I just wanted to make the most of the scion wood, I could make 2 short scions with two buds each from the lower section, and a third scion with bud C and the dormant buds at the tip, for a total of 3 grafts. With good grafts, good healing weather and protection from drying out, all three short scions would probably survive and grow well. In fact, this scion isn’t even that much of a challenge, because in spite of some buds being very sprouted, there are quite a few that are pretty dormant.
So, I remove most of the buds, and leave a few of the most dormant. If there are any larger dormant buds in good shape, leave one or more of them preferably, as the larger buds on a scion are generally primed to grow, while the very small buds are the tree’s insurance against things like browsing animals, late frost damage, or any other kind of losses that require those little back up buds to rise to the occasion. It is no accident that many dormant buds are often packed close together at the base of shoots. I the shoot is ripped off, or stripped of vegetation by a flood or browsing animal, they often remain intact to regrow the tree. If there is nothing better on the stick look for those tiny dormant buds near shoot bases or tips of the previous year’s growth.
While this scion has buds that are definitely pushing out, it also has dormant buds packed round the base. Three are pretty obvious (one is on the backside, but you can see the bump on the stem below the lowest sprouting bud). But, there are also more small dormant buds at the very base, represented by those lines you can see. Some are too small to see, or are just specks. How close to the base of the shoot these are, and how many, is highly variable. In this case, you might be able to pull off a short graft union and leave one or two of them. Personally, I would make a short graft, leave one or two of the dormant buds, pick off the lower swollen bud, cut above the higher pushing swollen bud, and seal the whole thing. If you left both pushing buds and ignored the rest, there is still a decent chance it would make it. But it’s better to tip things in our favor a little bit.
If you only have large buds on the scion and they are all showing green, leave just one or two of the least sproutingest. But if there are some good small dormant buds, I might leave just those and get rid of all the pushing buds. Small buds will usually be slow to develop and grow out, giving the graft plenty of time to heal. They may also result in weak growth unfortunately, but not necessarily, and if you get almost any growth you’ll have some material to work with next year to graft elsewhere.
One way that scions lose moisture more readily is through cuts of any kind in the bark. So if you pick off the sprouting buds, you leave open wounds that will lose moisture more quickly. Either way, seal the entire scion with something, including the buds you leave. Either wrap it in parafilm, or paint it with grafting paint to keep most of the moisture in. The buds should be able to push through the seal, but just check them in a week or two and provide a little birthing help if they need it.
This bud was showing green when grafted, as you can see under the paint. The worst sprouting buds on the scion were removed and the whole scion painted over with doc farwells grafting seal or in this case, heal and seal.
Same bud as above, 6 days later, having pushed right through the grafting seal.
In addition to these expedients, anything else the prevents desiccation and generally favors graft survival is good, like wrapping in tinfoil, or putting a paper bag over the graft, or any other shading. I’ve grafted stuff with only sprouting buds and no really dormant buds, and had success by just leaving the least sprouted buds, then sealing the buds and scion well and shading.
So if you get too busy to get your grafting done, or your scions get lost in the mail for an extra week, or the scions you cut when dead dormant decide to wake up in the crisper drawer of your fridge anyway, or you find a bag you forgot about hiding under a bag of slimy old carrots, don’t give up on them too easily.
