Mid spring is the time to start thinking about the “why” and “how” of fruit thinning.

Have you heard of thinning before? The technique is simple – it just involves removing some of the fruit from your trees, by hand. It’s one of the simplest jobs you can do each year on your fruit trees to help get regular crops. So why do so few people do it?

Even if you’ve heard of it, you might not really understand it. One of the least understood reasons for doing this job is to try to break the cycle of biennial bearing that many fruit trees naturally adopt.

But also, pulling fruit off your tree just feels wrong, right? We’ve found the best way to overcome this natural feeling of wanting to protect every piece of fruit is to understand the reasons for doing it.

How much fruit is too much?

Here’s a typical bunch of plums on a tree as they naturally set. As you can see, there’s LOTS of plums in these two bunches at the end of a small branch.

Angeleno plums before thinning
Angeleno plums before thinning

This is what we’d call a “heavy” crop. Having a heavy crop signals to the tree that it should take a rest next year, or in other words, have a “light” crop.

Angeleno plums after thinning
Angeleno plums after thinning

If we remove all but two of the plums, we’re sending the tree a signal that it’s having a light crop this year, which will encourage it to have a heavy crop again next year.

Can thinning remove too much fruit?

If you follow these photos, it looks like you’ve pulled a lot of fruit off, doesn’t it?

The good news is that if you do this job early enough in the season, you’ll be sacrificing very little actual fruit volume. The tree will put the same amount of energy into the fruit you leave on the tree as it would have to the big bunches of fruit. 

Result? The same weight of fruit, in less pieces = bigger fruit.

Well thinned plums that have grown to a good size
Well thinned plums that have grown to a good size

Managing the crop is one of your main jobs as the caretaker of your fruit tree. There are also several other excellent reasons for thinning as well, including:

  • protecting the structure of the tree
  • growing more fruit of a size that is usable
  • protecting your fruit from pests and diseases.

Knowing how much fruit to remove is the tricky bit. It’s one of the main things that stops people doing this job, or doing it properly. That’s why we’ve included charts to help you figure out exactly how much fruit to remove from any given tree in the Fruit Tree Thinning short course.