Thinning Fruit: why, when and how

The end of November is the perfect time to thin the fruit on your fruit trees if you have not already done so. You may think 'but why should I?' and 'won't the wind do the thinning for me?' This blog post explains why thinning is the way to go.

Why thin the fruit on your fruit tree?

I admit that I don't like the task much either, but if your fruit trees are laden with small fruits at the moment, thinning that fruit is absolutely worth the time because:

1. Thinning allows the remaining fruits to become bigger and tastier.
2. If you don't thin, you may have a large crop of small fruits this season, followed by a much smaller crop next season. It is called 'biennial bearing'. Trees produce well one year, not much the next, the year after that they produce well again, and so on. Early and rigorous thinning results in more even crops over the years.
3. Chances of Brown Rot taking hold are much larger if there is no space between fruits.
4. The weight of too much fruit can break branches, in particular on young trees. 

I ruined a fruit tree by allowing a far too heavy crop to come to maturity without thinning. One day a major branch collapsed under the weight. It nearly split the tree in two.

What is the best time to thin?

Ideally fruits are thinned when they are quite small. You can thin later of course, but the longer you leave it, the more energy the tree spends on fruit that you are going to remove. Growers spend a lot of time thinning early in the season.

How much fruit should you remove?

Imagine realistically what size you would like your fruits to be when they are ripe. Now make enough space between fruits so they still don't touch when they are that size.

That is the ideal way to thin. Not easy. I often thin fruit quite early in the season and then do a second thinning when the remaining fruits have become quite a big bigger.

By giving each fruit enough space to develop to full size you not only get bigger fruits. You also significantly reduce the risk that Brown Rot will ruin your fruits just before harvest time.

Below is an example of a branch of a peach tree before thinning (on the left) and after thinning (on the right):

 

After removing a bucket full of fruit, there is still ample left on the tree and the fruits become much bigger and juicier.

In addition to thinning fruit it is also a good idea to thin leaves on trees that have a dense foliage. That will provide better ventilation on warm humid days (there are likely to be some this summer). Once again, this will help keeping Brown Rot away.

Thinning flowers instead of fruits

In some cases thinning takes place even earlier. Flowers are removed before fruit sets. This method maximises the energy the tree puts into fruit that you want. Only consider this method if you know from previous seasons that this tree always has much more fruit setting than you want. 

A pair of long-handled tweezers is the ideal tool for flower-thinning. They will help you cut only flowers that you don't want to stay and not damage the ones you want to keep.

  

Happy thinning!

Max Bee