Cherrie production in southeast Idaho is a fickle business. Sour or pie cherries are suitably hardy for our climate. Unfortunately, their name matches their flavor. Eaten fresh they’ll make you pucker…though the birds don’t seem to mind. Sweet cherries on the other hand are a summer-time delicacy straight from the tree … if you can keep the birds out of them. They are also only hardy to Zone 5. Some hardiness maps will list much of our area in Zone 5, but this is laced with optimism. The zone itself isn’t wrong but surviving and thriving are two different things in fruit production.
The reality is that sweet cherry trees around here tend to be disease-prone and short-lived. I know both you and I have seen frequent exceptions to this tendency. I’m honestly not sure why some sweet cherry trees seem to do fairly well while the others of the same variety struggle in seemingly identical conditions.
There is a relatively new cherry alternative for growers in our region – the bush cherry. Let me get out in the open that bush cherries don’t substitute for sweet cherries. Bush cherries are slightly less sour than common sour/tart cherry tree varieties. In my opinion they are best thought of as being similar in flavor. However, they are much more cold-hardy (Zone 2) and their size makes them easier to harvest and care for. Few homeowners are interested in committing space to a sour cherry tree because they use so little of the fruit. Bush cherries fit in a small space yet produce profusely.
Bush cherries only grow about 6 ft tall, making them much easier to protect from birds. This allows a producer to leave the cherries to ripen longer on the tree, increasing the sugar percentage (Brix level) of the fruit. To give a comparison, Brix of a traditional sour cherry is about 15. Brix of bush cherries is around 20 and sweet cherries range from 20-30. This doesn’t show the whole story, however. Bush cherries have other compounds that make them more tart than sweet cherries (…with added health benefits, but that’s another story).
Bush cherries are referred to, more glamorously, as the Romance Series. Varieties include Carmine Jewel (most common), Romeo, Valentine, Juliet, Cupid, and Crimson Passion. Initial breeding and research was done at the University of Saskatchewan. I remember several years ago having difficulty finding a supplier of bush cherries. Now there are several commercial vendors offering them for sale. They are still fairly expensive and often run out of stock.
I’ve had Carmine Jewel bushes producing for three years. They are extremely productive. I’ve learned over time to delay harvest until the fruit darkens to a black/red. Picking them while bright red will lead to disappointment. They aren’t fully ripe until nearly a month after they first turn red. While I enjoy eating them fresh, we’ve used the bulk of them as pie filling and in making cherry jelly.