Yes, You Need to Thin That Fruit!

By Greg Peterson

I get so many inquiries about the amount of fruit people have on their trees this time of year.  AND here is the problem – the more individual pieces of fruit you have on your tree, the smaller each one is. This means that to the point that some of your wonderful peaches, which should be at least the size of baseballs, never really fully ripen and instead remain smaller than golf balls.  OY! And you could have done something about it!
I know, I know, thinning fruit trees and even pruning your trees can seem painful – but in the long run you are significantly helping your trees and fruit thrive.  Here at The Urban Farm a few years ago we had a late season freeze (in late February) and it knocked at least 80% of the fruit off the tree. Needless to say, I was significantly bummed…until May rolled around and I was picking some of the biggest, most flavorful peaches I had ever eaten.  Trust Nature, she seems to handle it every time.
So, the biggest reasons to thin your fruit are:

1. Less fruit equals larger more flavorful fruit at harvest time, improving the size, color and quality of the fruit on the tree,
2. Less fruit on the tree helps lighten the load to avoid limb damage and breakage (this also goes to pruning your trees which is another sour subject among new tree growers),
3. Thinning will help make your tree stronger next season and, interestingly, helps avoid biennial bearing. This is where the tree spends much of its energy to produce fruit one year and then needs a full year to recover and doesn’t produce fruit the following year.
4. By thinning you can also selectively thin out the lesser quality fruit to feed to the chickens, worms or compost.
5. Less and larger fruits are sweeter and more flavorful

OK, enough about that – there are more reasons – but let’s get to the good stuff.  You can easily remove 50% to 70% of the fruit off of the tree. Yes, you read that right.  It will significantly help your trees and you will get incredible fruit.
Let’s jump into methods of thinning:

• My favorite – shake the tree (lightly just to knock off flowers and fruit) a couple times a week starting when the flowers emerge all the way through when the fruit is about half size. Early on this will knock off flowers so that no energy is spent to make fruit. Hey, the earlier you get the fruit off the less energy you’ll spend on making fruit that you will be taking off.   Later in the season you will be knocking of larger and larger fruit.  At the point that the fruit is about 50% size, it’s time to jump into the next method…
• Hand picking – It is said that the best thing for a tree is to have a fruit every 3 inches. If you have a lot of trees this can get tedious (hence the reason for the early season shake) but if you still have a significant amount of fruit on the tree this is really your only option.  Remember for next year to shake the tree more early on in the season.

You will have to instinctively do thinning for the first few years until you have come to an understanding with your tree on about how much to remove.  It is a good rule that if there are multiple fruits touching that they need to be thinned.  Your best bet is to jump in and thin some, then watch the tree.  Don’t be shy—you and the tree can figure it out.
This next bit of advice comes from my varieties that I grow at The Urban Farm in the low desert of the Southwest United States.  So, although the stone fruit and apples should apply just about anywhere, if you are in a colder climate citrus won’t likely work for you.  My experience in thinning the different varieties is as follows:

• Apples seem to hold up really well under the stress of a lot of apples on the tree. This, however, is not an excuse to slack off of thinning. Branches don’t easily break and they tend to be ultra heavy producers.  Thinning them from this amount of apples at the end of a branch to 2 or three will significantly improve your yield.

Before thinning: Too many apples

After thinning: Perfect!

• Apricots & plums are nice because they are moderate producers so they are not creating so much fruit that they will break branches. Generally, here in the desert I leave them alone and don’t do a whole lot of thinning.
• Peaches are one of the heaviest producers of fruit. I visited a tree once that has so much fruit on it the tree literally broke all the main branches and we had to prune it back to a stump.  Thin your peaches heavily and then thin them a little more.
• Citrus is an easy fruit to grow as it is self-thinning. The trees know when to drop fruit, so if you are seeing some early fruit on the ground, don’t worry.  It is the tree taking care of itself.
• Grapes are simple – cut the clumps in at least half.

Like pruning, thinning your tree can be a difficult thing to wrap your head around.  But it is necessary and the quicker you can get past the struggle and thin away the better off your trees will be. 

Greg Peterson is a green living and sustainability innovator who is well-known regionally. He has appeared extensively on local television and radio and is a frequent guest columnist for publications.  His mission is “inspire people to embrace their own greenness,” which he does daily by living what he speaks. He received his master’s degree in Urban and Environmental Planning (MUEP) in December 2006 from Arizona State University.