American Cranberry, Vaccinium macrocarpon, farm

Wisconsin Cranberries and Pollination

The American or large-fruited cranberry, Vaccinium macrocarpon, is indigenous to the North American continent. It can be found along the northern portion of the United States from Maine to Wisconsin, and along the Appalachians to North Carolina.

Cranberries are a vital part of Wisconsin's agricultural economy as they provide more than 1/2 of the nation's total cranberry crop from 18,000 acres of beds. Another 160,000 acres are given to adjacent wetlands, woodlands, and uplands. Huge networks of ditches, dikes, dams and reservoirs are a common sight in Wisconsin to support cranberry production.

Wisconsin was responsible for 59% of the nation’s cranberry population with the production of 4.67 million barrels. Wisconsin’s gains roughly 4,000 jobs and $1 billion from cranberry production.

  Native Americans and Cranberries

American Cranberry
Vaccinium macrocarpon
Benefits: Bees, Birds
Light: Full Sun
Bloom: Late Spring
Early Summer
Soil: Acid
Flower: Pink
Height: 9-12 inches
Zones: 3, 4, 5

Native Americans did not cultivate it (called sasemineash by the Narragansett tribe), they gathered berries and used them in pemmican, a mixture of dried meat or fish and berries that was pounded into a pulp, shaped into a cake and dried in the sun.

Native Americans were the first to make it into a sweetened sauce using maple sugar. The berries were also eaten raw. Cranberries were used as a poultice for wounds and when it was mixed with cornmeal it was an excellent cure for blood poisoning. The juice was used as a dye to brighten the colors of their blankets and rugs. The early settlers called the fruit "craneberry" because before the flower expanded, its stem, calyx, and petals resembled the neck, head, and bill of a crane. It may have also come about because cranes found it to be one of their favorite foods. Through usage, the fruit eventually came to be called cranberry.

Many Wisconsin Native Americans eventually developed an itinerant economy. Putting in gardens at their homesteads, they harvested strawberries, cherries, potatoes, beans, and cranberries for white growers, returning home at intervals to care for and harvest their own gardens.

  Cranberry Pollination

Commercial Bumble Bees

The cranberry flower hangs upside-down with the flower opening facing the ground. The pollen and nectar are tucked up inside the flower. Bumble Bees are well suited to pollinate this type of blower because they use buzz pollination. Buzz pollination is performed by making the flower vibrate, causing the pollen to drop down and cover the bee with pollen and facilitating pollen transfer. Because of the ability of Bumble Bees to buzz pollinate, each individual Bumble Bee is a highly efficient cranberry pollination.

Approximately 30% of Wisconsin cranberry growers buy managed Bumble Bee colonies and place them on the marsh at a rate of 1 to 2 colonies per acre.

Commercial Honey Bees

Honey Bees do NOT buzz pollinate and, for that reason, each Honey Bee is less efficient at removing or transferring pollen than a Bumble Bee. However, the presence of approximately 40,000 Honey Bee worker bees per hive during bloom means that Honey Bees often do the bulk of the marsh pollination.

Approximately 90% of Wisconsin cranberry growers rent commercial Honey Bee colonies during bloom. These are typically placed on the marsh at a rate of 2 to 3 hives per acre.

Native Wild Bees

In addition to the use of commercial pollinators, over 400 species of native wild bees exist in the Midwest and many of them visit and pollinate cranberries. In fact, many Bumble Bee species are also native to Wisconsin. These native Bumble Bees along with other species of will bees are likely to be present in varying degrees on most cranberry marshes.

Flight Periods for Native Wild Bees Around The Cranberry Marsh

Flight periods for common groups of native wild bees found around the cranberry marsh.

  History of Cranberry Production In Wisconsin

Cranberry rake used for harvesting cranberries

For hundreds of years cranberry harvesters picked the wild berries by hand. Starting in the 19th century, the cranberry rake — a hand-held tool with a large comb at one end and a basket at the other — increased production. The rake allowed leaves and stems to pass through the tines of the comb while collecting the berries in the basket.

During harvest the marshes were flooded with 6 - 10 inches of water to make the berries float to the surface, where seasonal workers wielding cranberry rakes collected them. Each fall, large bunkhouses in Tomah and Wisconsin Rapids filled with migrant workers. Native American workers would set up camp on the grounds of some of the larger marshes to work as pickers. Workers were paid 75 cents per bushel, and in 1875 pickers averaged two bushels per day.

Cranberry flowers

The berries were then brought to a warehouse for cleaning, grading for quality and storage. At the end of a long day of picking berries, workers might look forward to dancing and music before retiring early to prepare for another day's labor.

During the 1945 season, German prisoners of war confined in Wisconsin worked in the cranberry bogs near Wisconsin Rapids. The prisoners worked in the marshes all summer, weeding the beds, digging drainage ditches and assisting with the harvest.

Around 1950 harvesting began to be mechanized. In 1949, 96 percent of Wisconsin cranberries were harvested with hand rakes, but by 1956 two-thirds were harvested mechanically. Commercial production in Wisconsin began near Berlin in Green Lake County in the early 1850s. The center of the industry later moved to marshes around Tomah, Warrens and Wisconsin Rapids. Today almost all berries are harvested by machine.

  How To Grow Cranberries

1. Choose a variety of cranberry for home growing that matches your interest for its use.

 Howes

Preparing a cranberry garden bed

Named for their discoverer Eli Howes in 1843. For many decades this was the standard variety of late berry. They were bigger, rounder, on stockier vines and ripened around the first week of October. Howes are a hard berry, demonstrating more resiliency against frost and better keeping quality (fruit rot).

 Early Black

Discovered by Cyrus Cahoon in 1847, it’s a small, dark, blackish-red berry ripening during the first two weeks of September. They are uniform in size and were once favored because they could be harvested before the hard frost of fall set in. They are not particularly productive and some feel that each upright bears fruit only bi-annually.

 Stevens

A very popular hybrid cross of ‘McFarlin’ and ‘Potter’ (a sub-variety of ‘Searles’ which is itself a wild heirloom dating back to 1893 in Wisconsin), this type dominates the market in cultivation. ‘Stevens’ was so named by H. F. Bain in 1940, in Whitesbog, New Jersey. The fruit ripens a bit earlier than that of ‘Howes,’ with a deep red color and lots of seeds. Vigorous vines produce high yields, and the fruit is juicy but low in pectin — perfect for commercial processing as well as home use.

 Ben Lear

This native wild type was selected for cultivation and named in 1901 by D. R. Burr in Berlin, Wisconsin. This is an early variety known for being very productive, with large, deep red fruit. It is often grown commercially via clones of the original wild plant, or used in breeding to create new cultivars.

2. Plant At The Right Time Of Year

Cranberries should be grown between zones 3 and 5. Cranberries can be planted at various times throughout the year, depending on the age of the plant.

  Cuttings and seedlings can be planted throughout autumn, from October to early November. They can also be planted in springtime, from the middle of April to the end of May.
  3-year-old rooted plants — which are still actively growing — can sometimes be planted in summer, provided they are purchased in pots.

3. Prepare the Soil

When it comes to soil, cranberry plants have unique requirements -- they need soil with a low pH value and a high level of organic matter. Before planting, wet the soil thoroughly (but do not saturate it). You can do this by misting the plot with the garden hose, mixing the soil periodically to encourage absorption,

4. Plant the Cuttings or Seedlings

Cranberry plants

It's important to be aware that cranberry plants do not start to produce fruit until their 3rd or 4th year — so whether you choose to plant cuttings or seedlings will depend on how quickly you want fruit.

Cuttings. If you choose to plant cranberry cuttings, plant them in the prepared wet soil, leaving approximately one foot of space between each plant. The root ball of each plant should be about 2 inches below the surface of the soil.

Seedlings: If you choose to plant 3-year-old seedlings, leave approximately 3 feet of space between each plant.

5. Fertilize the Soil

Soon, your cranberry plants will start to put out runners that grow along the ground. The runners should grow until they fill and cover the bed. If they do not, you can fertilize your cranberry bed with a high-nitrogen fertilizer. Only use fertilizer if runners are struggling to grow. Too much high-nitrogen fertilizer may cause overwhelming growth.

6. Prune the Runners

From the 3rd year of growth onwards, you will need to prune the cranberry plants each spring to control the runners and encourage uprights. You can do this by combing the cranberry plot with a landscape rake, until all of the runners are going in the same direction. This makes it easier to identify the longest runners and cut them back. Do not prune the existing uprights.

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