Spring Cleanup: Fruit Tree Pruning

The last week has been very, shall we say, “entertaining” in the weather department. A week ago, we had snow. It was beautiful...but kind of ridiculous for mid March.

The irises were not amused.

Luckily it melted fairly quickly, and a few days later we are back to the business of springtime. Crocuses are up, trees are starting to bloom (firing up my pollen allergies, unfortunately), and it's time to get to those early spring garden tasks. One such task is prepping veggie beds for planting: pulling weeds, cutting back any perennials, tilling in cover crops, and raking aside mulch and tossing it in the compost bin. Cats like to think of this task as “preparing the giant litter box”. Depending on the cat population in your yard, you might consider putting down some chicken wire over the top of the newly-prepped soil. I'll be talking about more veggie garden tasks soon!

Forsythia, in all its garish glory, heralding the end of winter.

Another early spring task is planting and pruning fruit trees. On Saturday I attended one of the Portland Fruit Tree Project's workshops. This one was on selection, planting, pruning, and care of young fruit trees, led by Rick Shory (really knowledgeable...contact Rick if you want someone to whip your fruit trees into shape), and it was a great refresher for me, as well as a reminder to give some attention to my own plum and apple trees. When I arrived home from work today, the lingering sunshine beckoned me out to the yard, and I spent the next three hours climbing around in the plum tree and getting it cleaned up. I made an unfortunate discovery in the process. The tree is suffering from a serious case of bacterial canker. Big bummer. If you see signs of this disease in your plum, cherry, or peach trees, make sure to address it right away before it spreads and becomes systemic.  This is what one of the symptoms looks like: oozing wounds on the branches. If you catch it early, it's treatable.

Do you have fruit trees in your yard? Are you thinking of pruning them yourself? If so, here are some things to keep in mind:

1. With the exception of removing dead, damaged, or diseased branches, trees don't “need” pruning. Usually tree pruning is done for our benefit, not for the benefit of the tree. The “right way” to prune a tree will depend on what you want from it.
2. Trees may not need pruning, but they will respond to it in fairly predictable ways. Some of these responses may be counter-intuitive to folks who don't know much about trees. For example, hacking back a tree canopy will encourage it to put on a burst of new growth, not very helpful if you pruned it because you thought it was too big. (If you plant a tree that wants to be too big for your landscape, you are setting yourself up for a lot of work and potential frustration. Planting a smaller tree species is much wiser than planning to control a tree's size through pruning.)
3. For fruit trees, pruning is usually used to influence the shape/size of the tree for easier harvesting, or to influence the size/quantity of the fruit to your preference.  For young fruit trees, pruning in the first few years can be used to establish the overall structure of the tree.  Those first little branches will become the limbs that support the whole canopy down the road.
4. In our wet climate, fungal and bacterial diseases tend to be a problem, and one way to combat them is to encourage air circulation through the canopy. Thinning out some of the branches in the interior of the canopy can accomplish this goal, and it also serves to bring sunlight into the canopy so that fruit can develop there. Bonus!
5. Tree branches that grow horizontally tend to produce more fruit than those that grow vertically, so pruning out vertical branches or bending them into a more horizontal position can give you a more fruitful tree.
6. When trees produce fruit, their goal is to make seeds to reproduce, so they will tend to produce lots of small fruits. If you snip out about a third of the immature fruits while they are still small, then the tree will put all of its reproductive energy into the ones you leave behind, resulting in larger fruit.
7. If you do remove a branch, whether because it is diseased, crowding the interior of the canopy, or too vertical, make sure to cut it back to a vigorous bud or an intersecting branch. Leaving a stub will impede the tree's ability to grow over the cut and heal completely.
8. If you're cutting out a large branch, chop off part of it first to get it out of the way, then go back and do the final cut close to the trunk or intersecting branch. The weight of a large branch can cause it to break as you saw it off, and you don't want that to happen on your final cut. The final cut should be at the “branch collar”, or the thickened bark ridge at the base of the branch. There's a good illustration here.

Here's an example of how I applied some of the aforementioned principles to my plum tree. See the big branch shooting straight up in the middle of the canopy? I wanted to remove this one to bring sunlight and air circulation into the tree.

That vertical branch only produces fruit at the top of the canopy where I can't reach it.  Boo.

I started with a first cut to get most of the branch out of the way, and I didn't have to be careful that it was nice an tidy. I just chopped it off.

I had to climb the tree to do this cut, which made it extra exciting.  I live an action-packed
life of danger and adventure, people.

Next I went back in and cut off the stub neatly. Looks like it was never there!

But you know it was there, because you saw the evidence.  You'll notice I removed quite a
 few of the smaller branches since the first picture, too.

Hopefully we'll get more fruit inside the canopy now, and the shade under the tree will be more dappled, allowing for a healthier lawn underneath. For this pruning session, I was lucky to have a supervisor on hand to oversee the process:

She runs a tight ship, this kitty.

Have you done any pruning of fruit trees?  If so, how did it go?  Is there a specific type of fruit tree that you would like to know more about pruning?