We have a Montmorency sour cherry tree in our back yard & this year it was prolific! They usually begin to ripen around the Fourth of July and harvest lasts a few weeks. At first we were battling the robins, cedar waxwings, finches, and other birds who were pilfering the fruit, but once we started picking, we realized there were more than enough for every one. The Montmorency cherries are indigenous to the upper Midwest and are the preferred variety for the standard cherry pie. Judging by my freezer, I cannot tell a lie... we are looking at lots of cherry pie this year!