Into the Marsh


There are many characteristics of a well functioning, productive cranberry marsh. In this lesson, three main features are highlighted: the locale of the marsh; the climate and weather of the marsh region; and the available resources that contribute to the well-being of the marsh.

Marsh locale: An excellent site for a cranberry marsh is an open area, although one surrounded by a grove of relatively innocuous plants, such as pines, is also acceptable. On the other hand, a marsh situated near a large swath of maples trees is disadvantageous. Trying to remove emerging maple saplings could destroy the cranberry vines as they grow. A marsh requires an adequate and readily available water supply. Similarly, a natural deposit of gravel and sand on site is a great advantage in that the grower does not need to pay for purchase and delivery of these necessary materials. Finally, a regular, rectangular shape provides maximum benefit. Machinery can maneuver about the marsh unimpeded by odd corners. Permanent equipment, such as sprinkler systems, can be installed more efficiently than in an irregularly shaped marsh.

Climate and weather: Many people know that cranberries are harvested in the fall, but they may not realize that all the seasons play an important role in the life cycle of the cranberry plant. The chilly autumn temperatures in Wisconsin are responsible for the cranberry’s deep red color, which is what consumers consider when purchasing berries. During the winter, the cranberry plant enters a crucial period of dormancy. Warmer weather towards the middle of April triggers the plant to emerge from its dormancy causing the buds to swell and the growing season begins. However, the young buds—and therefore the entire year’s harvest—are very vulnerable to damage by early spring frosts. During the summertime the buds turn to flowers, and the flowers begin to produce fruit. An appropriately wet summer season providing adequate water to the weather is critical. In summer, cranberries require rain each week; without adequate rainfall, the grower must irrigate the vines with a sprinkler system.

Resources: As with any enterprise, support systems are imperative for successful cranberry farming. Cranberry growers are dependent on the assured availability of a local water source to support the marsh’s needs during times when the local rainfall is insufficient. The need for water resources continues throughout the year, including the wintertime when harsh conditions can damage the dormant vines, and in the spring, when growers spray their vines with water to protect the plant from spring frost damage. It is essential, therefore, that the grower has a reliable reservoir of water on site for ready use.

State of the art technology enhances productivity. Such technology includes remote controls, as well as automated frost alarms and sprinkler systems; fertilizing, weeding, and harvesting equipment; and real time weather data and other information technology. These provide cranberry growers with tools that help them on a daily basis to grow more and better cranberries.

Cranberry agriculture is benefited by a community that is knowledgeable and supportive of its cranberry neighbor. Such a community might support open space initiatives aimed at protecting the upland regions of the cranberry marsh wetlands and ensuring adequate buffer zones between farms and land used for other purposes. The marshes, after all, exist within a wetland habitat. Their health depends on a healthy ecosystem—including a wide assortment of plants and animals. The wetland system recharges the local aquifer and provides flood control and storm water drainage. Just as growers benefit from local communities who are committed to open space conservation and wetland habitat protection, communities have a valuable partner in the cranberry grower.

Students have access to the information above via the interactive Web Resource, Give Me the Information. You will find that in the case of average rainfall, one year and one hundred year historical data are provided. While cranberry growers investigating a new site would not focus on rainfall information over such a wide time span, we include this data to help students better analyze typical rainfall amounts in a region.