Blueberries grow best on a sunny site in sandy peat soil, but they also do well in heavy soils if they are well-drained, aerated, high in organic matter and receive adequate moisture. The most important requirement for growing blueberries is acidic soil. If a soil pH is greater than 5 but less than 7, its acidity can be increased by applications of sulfur or acid peat. Soil acidity increases very slowly after applying sulfur. It is impractical to reduce the pH of alkaline soils (pH>7) low enough to grow blueberries. Blueberries suffer winter injury when the minimum temperature is lower than –29˚C. For best results, blueberries need a frost-free growing season of at least 140 days. Blueberry plants are self-pollinated, but berry size is larger with cross-pollination from another cultivar.