There is in fact no need to be worried that sour cherries, now re-marketed as tart cherries, will be sour or tart. It all depends on when you harvest them. What does this mean? It means there is a large harvest window for tart cherries, especially when you include the Romance series of tart cherry bushes developed by the University of Saskatchewan, which are hardy shrub varieties suited for a short growing season.
The university has developed some wonderful resources around their breeding program, including “ripeness cards” that show the varying colours, timing, and sweetness of your harvest. If you pick a batch early as I do (this year starting at the very end of June), to ensure you get some before the birds discover them, they will be a lighter colour and less sweet. Leaving them on the plant to ripen further, and become more sweet means waiting for up to another 3 – 4 weeks. If you plan to do this, it may be worth using some light cover cloth to protect them from being pecked.
Running through July and into early August, one can pick tart cherries, starting with those Romance series shrubs (Cupid, Valentine, Romeo, Juliet, Carmine Jewel, etc) and into the tree form types such as Montmorency, Meteor, and Northstar. Be sure to stop and appreciate the beauty of these ruby speckled shrubs and trees and their bright contrast of green and red.
Ottawa Food Forests 