Cranberry: The Bog Berry of New England

The American cranberry (Vaccinium macrocarpon) is one of only three commercially cultivated fruits native to North America (the others are the blueberry and the Concord grape). Indigenous peoples used cranberries as food, dye, and a wound-healing poultice long before European settlement. The Wampanoag word "sasemineash" gave us the early colonial name "sass-berry," which became "cranberry" — supposedly because the flowers resemble a crane's head.

Origin and native range

Cranberries are native to acidic peat bogs and wetlands across eastern and central North America, from New Jersey north to Quebec and west to Wisconsin. Wild populations still cover thousands of hectares of New England bog. The closely related European cranberry (Vaccinium oxycoccos) grows across northern Europe and Asia.

History and commercial cultivation

European settlers learned cranberry uses from Indigenous peoples. Henry Hall of Cape Cod, Massachusetts began the first commercial cranberry cultivation in 1816 — he noticed that wild cranberries grew best where wind blew sand over the vines, and built sand-bottom growing beds to mimic that. By the 1850s commercial cranberry bogs had been built across Cape Cod, southeastern Massachusetts, New Jersey, and Wisconsin. The famous wet harvest (flooding the bog and floating the berries to the surface) only became standard in the mid-20th century.

Where cranberries grow today

The United States (Wisconsin and Massachusetts) produces about 60% of the world's cranberries. Canada (British Columbia and Quebec) follows. Chile produces a small amount in counter-season. Cranberries cannot be grown commercially outside their narrow climate / wetland niche.

How to grow cranberries (it is harder than you think)

1. Climate: USDA Zones 2-7. Need cold winter dormancy.
2. Soil: Highly acidic (pH 4.0-5.5), peaty, very wet but not stagnant.
3. Sun: Full sun.
4. Reality check: Cranberries are essentially wetland plants. Without a permanent peat bog or carefully constructed wet bed, they are difficult to grow for fruit. Home gardeners can grow them as a groundcover in acidic moist conditions, but production will be light.
5. For home production: Use a half-buried tub filled with peat and rainwater, plant cranberry rooted cuttings, and keep the surface moist year-round.
6. Spacing: 30-45cm between rooted cuttings.
7. Fertilizing: Light. Cranberries evolved in nutrient-poor soils.
8. First fruit: 3-4 years.

Varieties

• Stevens — dominant commercial U.S. cultivar.
• Pilgrim — large fruit, popular in Wisconsin.
• Ben Lear — heritage Wisconsin variety.
• Mullica Queen — modern New Jersey hybrid, large dark fruit.

Nutrition

About 46 calories per 100g raw. Famous for proanthocyanidins (PACs), which appear to prevent some bacteria from adhering to the urinary tract — the basis for the traditional use of cranberries against urinary tract infections. Fresh cranberries are intensely tart; sweetened forms (juice, sauce) usually contain a lot of added sugar.

Bottom line

A wetland-adapted native that does not really fit a normal garden. Read about them, eat them at Thanksgiving, and visit a commercial bog harvest if you ever can — the flooded ruby-red sea of floating berries is one of the most striking sights in agriculture.