With approximately 15,000 acres of cranberry bogs, Massachusetts is the second largest cranberry-producing state. (Wisconsin is the first.) I recently spent an afternoon driving around southeastern Mass. looking at cranberry bogs and learning about cranberry farming.
Cranberries typically grow in wetland areas, thriving on the sandy, acidic soils and high-organic matter that are typically found in such ecosystems. They exist in harsh conditions such as those in bogs and other wetlands because they can withstand harsh winds and ice, and they are immune to many bacteria and diseases common in overly wet areas.
The cranberry is one of only three native American crops that are commercially produced. (The other two are Concord grape & blueberry). Indians first used cranberries as a food source, for dye, and for its healing properties. It wasn’t long before European settlers caught on to the benefits of cranberries, and they were first successfully cultivated in the early 1800s.
(To learn more about the natural history of cranberries, read my first cranberry entry.)
The first commercial cranberry beds were constructed in wetlands, but now they are usually built in areas with a shallow water table. An unflooded cranberry bed looks like a low field surrounded on all sides by a dirt berm. The topsoil is scraped off and used to build the berm, which serves as a dike. The topsoil is replaced with 4-8 inches of clean sand, which is shaped to have a slight hill in the center to promote drainage. The beds are installed with irrigation equipment and planted with cuttings from established plants.
A lot of people think that cranberry beds are constantly underwater but that isn’t so. Beds are irrigated regularly, but are only flooded twice — in the fall to facilitate easier harvest, and in the winter to protect them from freezing. Though it might sound counterintuitive, ice actually helps protect the plants. Sand is spread on the top of frozen bogs to protect them from frost damage and for pest control; when the ice melts, the sand settles to the bottom of the bog and helps replenish the sandy bottom.
Late September and October are peak cranberry harvesting months. When the berries are ripe, the beds are flooded and mechanical harvesters remove the berries from the plants. The ripe berries float in the water and are raked into a corner of the bed, where they are mechanically pumped from the bed. Because they’re harvested in water, helicopters are often used to transport the crop to a separate area for sorting.
I’m not through with cranberries. Stay tuned, a post on the environmental aspects of cranberry production is coming up.