Hi YooperGardener!

It sounds like your trees are overbearing. This typically happens because the trees get overzealous with their bloom production, & then they can't support all the fruits that come out of it. :) The fruits don't have enough resources (from the tree) to mature to full-size, & the tree will drop them as a natural aborting process.

I'd recommend bloom-thinning: in the spring, pull off blooms until you have 1 every 4-6 inches apart. Do this on as much of the tree as you can reach. Instead of losing a whole crop to overbearing, you'll be channeling the tree's resources into about 2/3 the fruit. You should get more full-sized fruit hanging around for your pies! :D

I'm attaching a link to a photo of an overbearing peach - you can see the size difference, & the comments on the photo shed some light on others' issues with overbearing fruit trees.

Best wishes!

Meg
(Stark Bro's)

Here is a link that might be useful: Overbearing Fruit

Thanks Meg....you might have a good point since it was LOADED with cherries.

I'm going to have to disagree with Stark Bros. I read commercial literature all the time and am not aware of any growers thinning sour cherries, or anyone recommending it.

My own cherry trees and other sour cherry trees I observe (several different varieties) never get thinned and do not drop any significant amount of fruit. Early pruning can reduce fruit load but that's entirely different from fruit thinning.

Peaches have a significant positive response to thinning. It takes about 35 leaves to size a peach. Too much fruit will send a hormonal response to the tree that causes June drop. However even in cases where trees are allowed to overbear, not all fruit will drop. A large amount of fruit will remain, although as Meg points out, the fruit will be very small.

Cherries are different. The common thought is it only takes 2 leaves to size a cherry. In my experience, it takes even less. I've seen small branches without hardly any leaves produce adequate sized cherries. So your fruit drop problem has nothing to do with over-cropping.

My guess is you've got a pest problem of some sort. Did you check any cherries for worms? How does the foliage look?

I have a meteor cherry just getting to bearing age (planted in 2007). The last two years it finally had a few blossoms, set cherries, and then they disappeared while still about 1/4 inch in diameter and green. I wondered if birds ate them at that size. It definitely wasn't overbearing. The tree is too tall to net very easily, so I hope that isn't a sign of what is to come.
Northwoodswis