Cranberry harvest.


Deryn Davidson, Colorado State University Extension – Boulder County

With Thanksgiving almost upon us, I thought it would be fun to take a closer look at the tart, red fruit that is a staple on most Thanksgiving menus. Whether you like to make your sauce from scratch, or you prefer to open a can and let the cylinder of wriggly jelly slide out, the cranberry is something we should all know more about.

A member of the Ericaceae family, also known as the heath or heather family, cranberries are related to blueberries, huckleberries, azaleas and rhododendrons. Members of this family prefer moist, acidic growing conditions which we don’t find here in Colorado. Wisconsin is the largest producing state, Massachusetts is second and New Jersey comes in third. In New Jersey, some call cranberries “Rubies of the Pines” because they are cultivated in the sandy, acidic soil found along the Pine Barrens (a heavily forested area of coastal plain).

There are several species of cranberry, but the one cultivated here in the United States, and most likely to be found on your dinner plate, is Vaccinium macrocarpon. They are a small, evergreen shrub that trails along the ground and in late spring they produce clusters of long pink flowers. According to lore, early colonists saw the flowers and thought they resembled the neck, head and beak of the sandhill cranes that were often found in areas that cranberries grew wild. They called the plant CRANEberry. At some point the name morphed to CRANberry, as we know it today.

The fruit of the cranberry have small air-filled chambers called bladders and a waxy coating that allow them to float. If you’ve ever checked out a raw cranberry, you know they have a Styrofoam feel to them. Native Americans used cranberries raw and cooked as food, medicine and dye. Mashed together with dried meat, they would make a long-lasting pressed cake known as pemmican. Today they are most commonly found as part of English Christmas dinners and American and Canadian Thanksgiving dinners. The fresh fruits are cooked down into a compote, jelly or sauce as an accompaniment to roast turkey. They are also sold dried and of course processed into juice. They are a good source of vitamin C, dietary fiber and manganese.

Commercial farming and harvesting of cranberries today is done very similarly to how it was done back in the 1800s. Large areas of land are leveled and surrounded by earthen dikes to create boggy conditions. This allows growers to regulate the water level depending on what stage of the process they are in. Stem cuttings are planted and in three to four years, they begin producing fruit. Harvesting is done by two methods, wet or dry. The wet method, which is most common, involves flooding the bogs above the vines and then running mechanical water reels over the vines to shake the berries loose. Because the fruit floats, once they are off the plant they can easily be pushed to the side and loaded into trucks.

The dry method uses a machine with teeth that pulls the berries from the vine and then moves them to large harvest boxes. Before the machines were developed, handheld cranberry scoops were used. Even with mechanical assistance, the dry method has higher labor costs and lower yield, but the fruit is less bruised and can therefore be sold fresh more easily.

Thanksgiving may look different for a lot of us this year, but hopefully cranberries will still have a spot at the table, as we all give thanks.

For more information, visit the CSU Extension Boulder County website at

By Deryn Davidson, Colorado State University Extension Boulder County