Production has been increasing at a considerable rate. For five years in a row, Wisconsin has been the largest producer of cranberries in the nation and there was a surplus of cranberries following the 1999 harvest. Cranberry production entails flooding cranberry fields several times a year to eliminate weeds, to aid in harvest, and to protect the plants from freezing through the winter. Large amounts of water are needed in the fall and winter, when ground water levels may be at their lowest. This water is discharged into waterways in the spring, when there may be potential flooding.
Irrigation is common for cranberry cultivation.
Cranberries and wetlands. Cranberries are plants that are found naturally associated with wetland habitats. Cultivated cranberries grow best in former wetlands or areas where water is at or near the surface. At the least, abundant water is necessary at regular intervals throughout the year for the cultivation of this crop. Cranberry marshes or bogs have historically been developed in former wetlands, where the original wetland vegetation is removed and replaced with perennial cranberry varieties.