I learned this at the Mother Earth News Fair when I attended a lecture by Ann Ralph, who wrote the book Grow a Little Fruit Tree. It was a great talk, because she distilled pruning down to three basic cuts, and two times a year, and giving the all important explanation why.
It all boils down to stored energy. Trees store their energy in the form of sap. In the winter, sap is stored in the trunk and roots, and in the summer it's freely flowing up until the time of the summer solstice. At that time, the sap stops moving to the ends of the tree and growth for the year slows way down, and the sap starts to flow back into the trunk and roots. By the time it's autumn, the sap is pretty much out of the branches and the tree goes dormant. This is why you're better off transplanting a bare root tree in the autumn and winter, rather than planting a potted tree in the spring.
So the first thing to know about pruning is that cuts made in the fall, winter, and spring will result in bushy growth, because after the cut, the tree still has a lot of energy to move, and it will expend that energy growing branches. A lot of new ones. This is good if you're trying to get your tree to fill out, either during its first year or at a specific area in the tree. Cuts made at or just after the summer solstice will result in less aggressive growth, so that is when you want to prune to contain the growth of the tree.
The second thing to know is that you are in control of the size of the tree at all times. Don't worry; I didn't know that either. But what about dwarf and semi-dwarf rootstocks, you say. If you read the fine print in the nursery catalogs you'll notice that a dwarf rootstock still results in a ten to fifteen foot tree, which is way taller than you or me. Ms. Ralph said that it really doesn't matter what the rootstock size is because you can control how big you let the tree get; what you want to pay attention to in a rootstock is how well it does in your soil and climate. Some rootstocks are better in well drained soil and some can handle heavy clay. You should go with a rootstock that will handle what you're going to give it, regardless of what kind it is. So even though you wanted that Elstar apple and it's only available on a standard rootstock but you wanted a much smaller tree, you can go ahead and get it.
Assuming you bought the standard sized tree during bare root season which is the best time to get a fruit tree, once you get it into its hole and all tucked in, it's time to make the hardest cut you'll ever make to that tree. Cut the tree off at a forty-five degree angle with a very sharp pruner or lopper so that it's now at the same height as your knee, even if it has branches on it higher up. Yes, your knee. Remember, we're growing a small tree here. It's okay, you can do it. When I espaliered my apple trees, I cut them all at eighteen inches and they were fine. Come spring when the sap starts to flow, you will find lots of new branches growing on your tree.
So now it's spring and you have lots of branches. Keep an eye on where they're growing and the direction they are heading; if you have a lot of branches growing toward the center of the tree criss-crossing each other, you'll want to take most of those out at the solstice. All trees ripen fruit by the exposure to sun which helps develop the sugars in the fruit, so you want to keep the canopy open so that sun can reach into all parts of the canopy.
|My stump cut|
|New size and shape. Long branches |
will be taken out at solstice
|The other Lapins. The long branches|
will be removed altogether with
thinning cuts at solstice
|Pluot with an open fountain|
shape. All I have to do is
control its size
|Pluot with a bad shape. It|
will have to wait until next
winter to be corrected
Getting ready for all this work means getting my Felco pruners tuned up, which I did yesterday. You can see how to do that here. My Felco pruners have stood by me for almost fourteen years; they were the first ever birthday present that Steve got me, even before we were married, and they have been great. If I needed to, I would definitely buy another pair. They have kept in reasonable shape all these years and now that I've cleaned and sharpened them again they are practically like brand new, and I use them a lot. The classic Felco pruner is the F2, and they make an identical pruner for smaller hands which is the one I have; that one is the F6. The videos for disassembling, cleaning and sharpening, and reassembling are shown with the F2 but they work for the F6 as well. You can expect to pay around fifty bucks for the Felco pruner. If you need to buy pruners but don't want to shell out for the Felcos, at least look for a pruner that you can take apart to clean and sharpen. Fiskars appears to make one here for around seventeen dollars.
Today is the nineteenth of June, which means you have two days to get your pruning gear tuned up. If you have time, it might help to go out and take a look at your trees to make mental notes about where you'll make your cuts and what you have to do. To recap, you'll be looking to thin and control the size of the tree with heading and thinning cuts on or right after the summer solstice, which is the twenty-first of June. Next winter you'll be evaluating your trees to see where you should be encouraging growth, and pruning to help shape the tree.
I am giving myself several days to get this all accomplished, because with eighteen trees to prune, I'll be pretty busy. The good news is, this time I'll really know what I'm doing.