The IMPORTANCE of Summer Pruning an Apple Tree - Part 1 of 2

Let's talk about summer pruning. But hey, did you know there are two basic times of year when you prune your trees? Most people are familiar with winter dormant pruning, but summer pruning is an integral part of the picture too. If you were to make an analogy, and I will, it's like building a house. Winter pruning is like pouring the foundation, putting up the framing, the superstructure. Summer pruning, you've done that outside work, you're moving inside, you're doing the molding, the tile work, and the cabinetry. It's a refinement of the basic tree that is formed via winter pruning. Okay, it's August 19th. It's definitely summer. Look, things are growing. It's cool. And there are two basic routes or avenues to go when you're summer pruning. One involves, and it's a great tool, reducing or limiting the height of a tree. The other, which we're going to demonstrate here on this young four-year-old apple, has to do almost exclusively with the training and pruning of lateral branches. The goal is to stop extension growth and to induce early fruit bud formation. When I say early, I mean early in the life of the branch. If a lateral is left alone to grow, it will grow undoubtedly too long. Set fruit at the end, sag, maybe break. If you summer prune it, it will be shorter, stouter, better able to bear that fruit closer to the main branch. And phenomenally, it will set up fruit buds, induce fruit buds earlier. Whereas if left alone, it might take two or three years to form fruit buds. With summer pruning, it can form fruit buds even in this same season. We might expect to see fruit buds and flowering later in September. That's a spectacular step forward to bearing more fruit. Okay, let's move on. Here we are with a beautiful four-year-old apple tree mid-summer. And let's look at it as you do every time you go out and prune a tree, whether it's summer or winter, and assess what are the needs. So let me run you through that. If you look down to the base of the trunk, you'll see these what are called rootstock suckers. These are very vigorous shoots that grow from the rootstock and not the scion or the preferred variety up top. They will basically grow you out of house and home. So we're going to thin them. Let's thin them. Just cut them out at the base. Now let me just say that some rootstocks, particularly this rootstock, which is an excellent all-around semi-dwarfing rootstock, M7 is the designation. One of the negative things about it is that it throws rootstock suckers annually. You'll spend your whole life, the life of the tree, pruning them out. It's the way it is. So I did that. When I look at this tree, I am enamored of it. I am enamored of its form. It is a nice open-centered tree. Let's point to the primary branches. One, two, off in the distance, three, and over here, four. And they grow up and out into the sunlight. And when we're done, you'll be able to see a distinct round opening at the top that allows sunlight to infiltrate into the core of the tree. I'm pretty happy with the prior work that I've done with this tree in terms of both training and pruning, but there's always a little need for continued work. So I'm going to spread these two branches a little further apart like that. That's a little minor tweak, but the amount of sunlight that will penetrate into the core here would be considerable based on the few inches that I've moved this branch. And then this branch is quintessentially beautiful, and I'm going to use it in a minute to demonstrate how I would go about summer pruning the laterals on a tree like this. But it's also a little more upright and dominant than I like, so I'm going to try to train it out just a bit like this. Another alternative would be to loop some twine around it and drive a stake and have a tie down, but this should work quite well. So my tree is performing well. I had some issues with rootstock suckers. I dealt with those. I did a little bit of refinement. Again, refinement is a good word associated with summer pruning, with training these branches, primary branches by spreading them. And now I want to look at the actual meat of it in terms of what are you doing when you're summer pruning the laterals of fruit trees. But first we have to look at some indicators as per when is it the right time to summer prune. You can use the calendar and that's all right, but also generic in that generally you summer prune in about from about mid-August to the end of September. And that's based on how the tree is growing in any given year, and that can be off by as much as two or three weeks. But that's the general time of the summer when you're thinking about fitting summer pruning in. But there are some other physiological indicators, and one is that you want to look at your branches and you want them to have primarily stopped growing. How do you know that? Let's look at a few right now. Let's look at a branch that is still actively growing, and that means it's unfurling leaves at its tip. This would be a good example. You see one, you've got light green lush active growing material here, and it's very obviously growing. Let's look at this branch here, which is twixt in between a bit. It's kind of starting to form a terminal fruit bud and stop its growth. Let's look at a done deal over here. This is a really prime example of the cessation of summer extension growth on a branch, and you can see it's forming a fat bud, a fat terminal bud, which is on its way to becoming a fruit bud. That's a good indicator when most of your tips of your branches have stopped growing and unfurling leaves. There's another helpful tool, and that is, there are two other helpful tools. One is when you've got about a foot or more of extension growth, new growth. This branch grew from here to here, probably 15, 18 inches, fits the bill. Another one is, what is the degree of woodiness or firmness at the base of your lateral branches? I'm going to use this to demonstrate. You'd like to be able to get an audible snap when you break this branch. Listen up. Good enough. Okay, so the calendar says it's time to go. The setting of terminal buds by and large on most of the lateral branches say, go, go, go. The snap of the wood says, yes, it's time indeed. Let's move into how I would treat a main branch and its laterals for summer pruning. Okay, let's look at this branch here to demonstrate the principal methods of summer pruning of laterals. I'm going to just dive right in and show you that, and then we'll look at this whole section of the tree and branch by branch summer pruning. Okay, we've determined it's time to go. The time for summer pruning is now. And here's a big difference between winter and summer pruning. In winter pruning, if you cut a branch back, it will stimulate it to grow. It's absolutely proportional. The more you cut it back, the longer and stronger it will grow in the next summer. Summer pruning, all bets are off in a sense. Summer pruning just limits, not just immediate, but intermediate and long-term extension of a branch. Thus, I can determine if I want this branch to be this long or this long or this long. I simply cut it there in the summer, and way more rather than less, it will behave. Your goal, one of your goals with summer pruning of laterals is you want short, stout branches that bear the fruit in tight to the main branch here. The danger, as it were, in leaving this long is that it will set fruit here and sag and or break. So I will make a heading cut on this at the point I want it to stop growth. But before we do that, let's look at this branch and backtrack its history here. This is a two-year-old branch, and you can see, hopefully, on this older wood here, we already have fruit buds forming. Here is one, and that's good. Well, I'd like to have this next section of branch replicate that with two, three, or four more buds, and that's it. That's as much as I expect or want or can reasonably get from a branch like this. So I'm going to head it back. Now, I'm looking here at this demarcation, this little stub here. This is previous year's growth. This is current season's growth. Here's a very specific methodology developed by a Frenchman, Louis Lorette, in the early 1900s for the summer pruning of laterals. And that goes like this. You look for the new wood. It begins here, and usually you have a circle of leaves here. You don't see a distinct node and inner node area as you do here. Whenever you see a distinct node, inner node area, you start counting. I'm going to start counting, and it's one, two, three, cut above the fourth one. So I've got one, two, three, head, like that. Okay, we've taken a branch off a tree to get a little zoom in on the three bud system of summer pruning of laterals. Let's take a look here. If you note a little pruning stub here, that's the demarcation point of old growth, current season's growth. You start with the new growth, current season's growth, and usually you have a tight cluster of leaves. I call it a subtending cluster of leaves. Ignore that. But when you can see distinct difference between the nodes, start counting. One, two, three, prune. So this bud hopefully will grow, but just a bit. These next two buds back below it will form fruit buds. That's three bud pruning in a nutshell. You don't have to do that in that degree of specificity. You could just say, you know, about four or five is good, and that works too. When I say four or five, I mean four or five buds or nodes. What do I expect? I expect this top bud, of course, to remobilize and try to grow, but it won't grow much. The reasons being we're late in the season. All of this tree's resources are tapped out, kind of put into root shoot, flower, etc. There aren't resources to grow it. The other thing is we're late in the season. There isn't much time. The other thing is that as a result of making this heading cut here, I have the good chance of getting one, two, three buds here to form as fruit buds. This could happen as rapidly as this season, next month. We might even see some flowering. We pinch the flowers off and then let these fruit buds set fruit next spring. So in the end, I would have a nice short lateral branch here with about a half a dozen fruit buds, and I would only actually probably be able to bear maybe one, two, three fruit in here as far as spacing and good size on the fruit. And I would have a similar pattern like that up and down this branch. All right, let's get specific about summer pruning, the summer pruning of laterals. Let's look at this branch here. Let's look at this main branch, which has quite a number of laterals coming off of it. Some good, some needing treatment. Let's look at one in particular. Let's look at this very short lateral. It is what I call a self-managing lateral. That is, it is a branch that has grown from an inherently weak bud and has just grown about six or seven inches and stopped growing. It needs no treatment. Would that all your laterals were like that, you wouldn't have to do summer pruning. But they're not, so you have to do some summer pruning. Let's look at this branch here. It comes up and out, but extends too far. I'm going to cut it back. Now there's two ways that you can cut back laterals with summer pruning. One is generic, not slipshod, but generic. It goes like this. I think I can cut it about there. And that equals that. That's a good length for a lateral branch, and I'm hoping to induce fruit buds here. Let's work our way up this branch here and do the treatment that's needed for each of these laterals. This is almost a self-managing branch, but I'm going to just cut it a little shorter. Boom. Get some fruit bud formation here. Again, what you want is short branches that can hold their fruit tight to the main branch here and are self-supporting. This is the aforementioned self-managing lateral. This is the one that I pruned previously. Let's look up the branch here. This is what a teacher might refer to as a conduct disorder. It just doesn't know how to act in class. It's too vigorous and too upright. I could possibly train it down and tame it, but when you have an overly vigorous upright, probably the best thing is to either thin it in its entirety, or if you're like me and you're greedy and you love fruit, you simply cut it short to one bud. Hopefully this will just hang a fruit there. If it tries to grow too vigorously, then thin it. Let's continue up here. I've got a nice lateral. I'm going to just be a little generic and cut it here. All right, we did a little reset with the camera. Let's look at this side of the branch and let me show you a little more specific approach to the summer pruning of laterals, and that is the three bud system. I look for the point at which new growth starts, and that's right here. At the base of new growth, you have very close inner nodes. I call it a subtending circle of leaves. Ignore that, but when you can start to see distance between the nodes, you start counting. One, two, three, cut. Let's move down here. New growth and a subtending circle of leaves. One, two, three, cut. It's a bit like a waltz. One, two, three, one, two, three. Okay, we've got that. I've got this other branch over here that I didn't show you. Let me treat it, and that's to say coming out here, I have two vigorous growths. I'm going to thin the more vigorous and upright, and I'm going to shorten this one here. Back here are two unwanted upright branches that I'm going to thin and a third one here. Okay, this is a pretty good example of how you might treat the laterals on a primary scaffold branch on a four-year-old apple. This would apply to an apple through its midlife, and that is I have selected a number of laterals that I like, and I have shortened them variously. I have shortened them in a generic sense about this long, and in some instances, I have counted one, two, three buds and shortened them that way. I have pretty good spacing vertically, and I have nice, short, stout laterals. What am I expecting? I'm expecting this region of each of these branches to produce fruit buds, maybe even this year, certainly next year, and this will have a long, fruitful life bearing maybe three to five apples on it each year. We're good. Okay, here we are with a three-year-old apple tree that we summer pruned about five, six weeks ago. Let's check in. Let's actually just frame it a little more first. On apples and pears particularly, you want to think about summer pruning of laterals, and you do this for a number of reasons. One is they tend to grow long, sag, and be either not fruitful or only have a few fruits out towards the end of the branch, become serious saggers, could break. What you're looking for is a short, stout lateral that can carry fruit, and it'll be tighter to the main branch. So if we look here, we see two excellent laterals. I summer pruned these. They are short. Anytime you cut back a to form a fruit bud, which normally will take a couple, three years if left unpruned, but I'm hoping to have it happen soon, and in fact, if we look down here, you'll see an example of a success story. This is a lateral I pruned again five, six weeks ago. Growth stopped. Now growth stopped on this one too, but I didn't get a fruit bud forming, but I did get a fruit bud forming to the point where we have a cluster of flowers and a few little apples set. Now I don't want apples on this tree at this time of year, October, but it's a success story because I formed a perennial organ, a fruit bud, so I'll just nip the young fruit off, grow the fruit bud, and next year in the spring, it'll set a nice big apple like that. So let's take a closer look at this. So let's take a look at a successful summer pruning venture. If you note down here, a nice lateral coming up maybe eight, nine inches like that. It had been longer. I pruned it back, and again, when you prune back a branch, it gets thicker and is stronger and can bear more weight, the weight of the fruit, but what you're also trying to do with summer pruning is to induce the rapid formation of fruit buds. That happening in five or six weeks is way rapid. Usually it takes two or three years, but we have a success story here. If you note, you can see the pruning wound where I pruned again five, six weeks ago, and we got a little short week shoot growth terminated in a fruit bud. There's a pink bud stage flower and a few other flowers here that have just dropped their petals on our setting fruit. That is a success. That makes me happy. So I don't want fruit on this at this time of year. I will come and pluck off the fruit, and the next spring, the fruit bud will express again, bloom, hopefully get pollinated, and set a nice good size fruit. So it's a good thing to do to your laterals. It keeps them short. It keeps light all around them, and it can help you increase the time to cropping and the amount of fruit you bear, and it also really helps with the quality of the fruit. Let's look at another variation on this. If you look here, I had a shorter lateral that I summer pruned here and here, and I got an okay response. I didn't get a resumption of vegetative growth, which I'm not interested in, but I got what, if you see this lighter colored cluster of leaves here and look down to the center, I got the beginning of a fruit bud forming, and that's good too. So in summation, well summation so far, we're standing with a three-year-old apple. Grew well this year. Nice extension growth. Had a light fruit load. It was good. Did summer pruning of the laterals. In some instances, as we've demonstrated, got a good response. That is an almost immediate formation and expression of a fruit bud and flowers. So where are we going? It's not inconceivable that some of the shoots that I summer pruned that simply stopped growing, which is a partial victory, will express a fruit bud between now and dormancy. Dormancy. Here we are at 400 foot elevation, three miles from the Pacific Ocean, at 37 degrees north of the equator and central coast of California, Santa Cruz. Our season is long, virtually frost-free. A young tree like this will probably continue to grow well into the fall, perhaps even well into December, before it sheds its leaves and goes briefly dormant. We'll pick it up at that point and we'll look at it for winter pruning. One thing about trees, when they drop their leaves, is it's so easy to see their structure. What's right, what's wrong, and how do you fix it?