Cranberry

Growing Conditions

Growing Zones

Thrives in USDA Zones 3 - 7

Companion Planting

When to Plant

• Transplant

  Plant rooted cuttings or plugs in spring in prepared acidic bog bed; keep soil consistently wet after planting

• Harvest

  Harvest when berries turn deep red in September - November; pick by hand or rake; berries store well in cool conditions

Organic Growing Tips

• Prepare a proper acidic bog bed before planting; no amount of aftercare compensates for wrong soil pH.

• Flood the bed or fill a lined bog trench with water in late autumn to protect overwintering plants from desiccation.

• Apply fresh sphagnum moss as a topdressing each spring to maintain acidity and moisture.

• Renovate overly dense mats every 4 - 5 years by raking or mowing in spring to encourage new productive growth.

• Net the bed in September as berries colour to protect from birds.

Common Pests

• Cranberry Fruitworm
• Blueberry Maggot
• Powdery Mildew
• Mummyberry Fungus

Taxonomy

Kingdom

Plantae

Family

Heath family (Ericaceae)

Genus

Vaccinium

Species

macrocarpon

Natural History

Vaccinium macrocarpon, the large cranberry or American cranberry, is native to the sphagnum bogs and acidic wetlands of eastern North America, from Newfoundland to the Atlantic coastal plain south to North Carolina and inland to the Great Lakes. The cranberry is one of three commercially significant native North American fruits - alongside blueberry and Concord grape - and is the largest agricultural crop in Massachusetts, Wisconsin, New Jersey, Oregon, and Washington State, as well as British Columbia. Indigenous peoples of eastern North America, including the Wampanoag, Haudenosaunee, Ojibwe, and Mi'kmaq, gathered and used wild cranberries for food, dye, and medicine for thousands of years before European contact. The Wampanoag name for cranberry, sasemineash, was documented in early colonial records, and the fruit was incorporated into pemmican by multiple nations. European settlers quickly recognized and adopted cranberry as a food, and by the 18th century it was traded commercially from New England ports to Europe. The commercial cultivation of cranberry in flooded bog systems - the familiar image of flooded red-carpeted bogs at harvest time - began in the early 19th century in Massachusetts and represents one of the oldest continuous native plant domestication industries in North America. The berry's exceptional keeping quality when raw, owing to its high benzoic acid content, made it a practical food for sea voyages and long winters and drove its early commercial value.

Traditional Use

Cranberry has one of the most extensively documented traditional and modern medicinal uses of any North American native fruit. Indigenous peoples used it as food, dye, and medicine; colonial and early American medicine adopted it as a preservative, food, and remedy; and the 20th century produced substantial scientific interest in cranberry extract for urinary tract health, culminating in a large body of clinical research. The modern understanding of cranberry's proanthocyanidins (PACs) as anti-adhesion compounds that prevent certain bacteria from attaching to urinary tract walls has given scientific context to the historical urinary tract use.

• Wampanoag and Haudenosaunee peoples, northeastern North America - Berries

  Wampanoag and Haudenosaunee ethnobotanical records document cranberry use as food and medicine. The berries were eaten raw, cooked, dried, and mixed into pemmican and other preserved foods. Poultice preparations from the berries were applied to wounds, reflecting the intuitive use of an acidic, antimicrobial fruit for topical applications. Internal use included preparations for urinary and kidney complaints, documented in multiple northeastern Indigenous nations' ethnobotanical records.

• Colonial American and 18th - 19th century folk medicine - Berries and juice

  Early American medical writers noted cranberry preparations as useful for stomach complaints, fevers, and urinary conditions. Cranberry sauce became a standard part of the American diet, and the fruit appeared in domestic medical manuals as a diuretic and urinary tract remedy throughout the 18th and 19th centuries. This tradition was consistent with Indigenous use and persisted into 20th-century folk medicine.

• 20th century clinical research, North America and Europe - Berries and standardized juice

  From the 1980s onward, cranberry became the subject of clinical trials examining its effect on urinary tract infections (UTIs). Research identified proanthocyanidins (specifically type-A PACs) as the compounds responsible for preventing Escherichia coli and other bacteria from adhering to urinary tract epithelium. Meta-analyses of clinical trials show mixed results: cranberry appears to offer modest preventative benefit in recurrent UTIs in some populations, particularly in women with recurrent infections, but is not a treatment for active infections and should not replace prescribed antibiotics.

Cranberry is safe as food in any culinary quantity. Concentrated cranberry extract supplements or large volumes of cranberry juice may interact with warfarin (a blood thinner), potentially increasing anticoagulant effect; people on warfarin should consult a doctor before taking cranberry supplements in therapeutic doses. Cranberry juice should not be used as a substitute for prescribed antibiotic treatment for urinary tract infections.

This information is provided for historical and educational purposes only and is not medical advice. Always consult a qualified healthcare professional before making decisions related to your health.

Morphology (Plant Structure & Identification)

• Root System

  Very shallow, fibrous root system dependent on moist, acidic, low-nutrient peat or sphagnum conditions; roots associate with ericoid mycorrhizal fungi to extract nutrients from the acidic bog environment.

• Stem

  Slender, wiry, creeping woody stems forming a low mat 3 - 6 inches tall; stems root where they touch moist soil, spreading the colony outward.

• Leaves

  Small, alternate, oval evergreen leaves 0.3 - 0.6 inch long; dark green above, paler below; slightly rolled at the margins; persistent through winter, turning bronze in cold conditions.

• Flowers

  Small, reflexed, pink flowers with protruding stamens, resembling tiny shooting stars; produced on upright shoots in June - July; attractive to bumblebees.

• Fruit

  Round to oval berries 0.5 - 1 inch across, initially white, ripening to deep red in September - November; tart and firm; exceptionally high in benzoic acid, which acts as a natural preservative allowing raw berries to keep for months in cool storage.

Known Varieties

Common cultivars worth knowing

• Stevens

  The most widely planted commercial cranberry variety; large berries and high yields on vigorous upright vines; good for home bog plantings.

  Best for: General production, large bog plantings

• Ben Lear

  Early-ripening variety with deep red colour; suited to cooler, shorter-season climates.

  Best for: Cold climates, early harvest

• Pilgrim

  Large-berried variety with excellent flavour; named for its New England heritage.

  Best for: Fresh eating, fresh flavour quality