How Cranberries Grow: Ice Sanding
Ice sanding occurs typically mid January through mid February
Cranberry growers in Massachusetts flood their bogs to protect cranberry vines from the frigid temperatures and drying winds of winter. The cold temperatures turn the floodwater into ice, allowing cranberry growers to access their bogs to spread sand. Spreading clean sand on cranberry bogs is a practice that dates back to the commercial birth of the industry. In 1816, Captain Henry Hall of Dennis, Massachusetts discovered that sand blowing on his cranberry vines stimulated the vine's growth. He quickly began spreading sand over his vines on a regular basis.
Ice sanding occurs typically mid January through mid February when conditions favor the formation of enough ice to support the sanding equipment (generally 3-4 inches of ice is the minimum requirement). Grower’s use home made ice sanders that will spread an even layer of sand on the ice. When the ice melts the sand will sift into the vines.
Sanding is a Best Management Practice and is also part of a Integrated Pest Management program. Sanding can aid in pest control by burying weed seeds, fungal spores, insect eggs and over-wintering insects. The primary benefit of the sand layer is to stimulate the development of new roots and to cover the bare wood at the base of the plants, leading to renewal of the root system and the production of new shoots. By sanding, growers can reduce the need for fertilizers and pesticides but can limit production for the year. This impact is lessened when sand is applied on the ice rather than directly on the vines in the spring.
View a slideshow on cranberry bog ice sanding.