Vaccinium macrocarpon

Large cranberries contain internal air pockets, so ripe berries can float after a cultivated bed is flooded. Mechanical harvesters loosen the fruit, which is then corralled on the water's surface; cranberries do not normally grow underwater.

Large cranberry needs acidic soil, steady moisture, and abundant sun, with commercial beds often built from layers of sand and organic material. It belongs to the same genus as blueberries and performs poorly in ordinary alkaline garden soil.

Vaccinium macrocarpon flowers can be self-fertile, but insect activity greatly improves commercial fruit set. Growers commonly rely on honey bees or native bees to move pollen among the distinctive reflexed flowers.

Vaccinium macrocarpon is the large-fruited North American species behind most commercial cranberry products in the United States. Vaccinium oxycoccos is a smaller-fruited species with a broad northern distribution that includes Europe.