Modern cranberry marshes are completely sprinkle irrigated. Sprinkler systems may be buried under the surface of the beds, or placed on the surface and removed before the harvest. There are advantages and disadvantages to both approaches. Sprinkler systems must be designed to provide even, thorough coverage across the beds. Although the cranberries are wetland plants, they do not grow under water or in standing water.
Excellent drainage is essential, as is application.
Cranberry beds are ringed by drainage ditches to allow water to drain from beds. Many beds have one of more drainage tile lines running the width of the bed. The water table is manipulated during the growing season to remain 12 to 18 inches below the surface of the bed. Because sites suitable for cranberry production are frequently low lying, frost is a constant threat. Air temperatures below 32 degrees F can damage new growth, flowers and immature fruit.