February is National Cherry Month. The birthday in February of George Washington, coupled with the story of his toppling of a cherry tree, appears to be the reason for the this rather fanciful association. Besides enjoying a serving of cherry pie in February, it is a good time to review the virtues of the sour, or pie, cherry for the home gardener. Unlike sweet cherry varieties, sour cherry trees are among the most hardy of tree fruits, growing as far north as Canada. The trees tend to be comparatively large, so suburban gardeners need to choose a planting location carefully. A few varieties need a second tree as a pollinator, though a neighbor’s tree may serve the purpose. Pie cherries have either red or yellow flesh depending on the variety. The most common variety in use, Montmorency, has yellow flesh with a red skin. The red-fleshed, or Morello, varieties tend to be more tart with a more emphatic cherry taste. Northstar is a Morello cherry that grows on a compact tree. Red fleshed cherries should be allowed to ripen fully in order to develop their sweetest taste. For a richer flavor in cherry pie or cobbler, add some almond extract to the filling.