Characterization Descriptors for the "Big Rainbow" Heirloom Tomato
Infinite Seeds Association
We curate, preserve, and reproduce a collection of 1,700 heirloom tomato varieties for public use. We work to prevent genetic erosion.
History and Origin of the Variety
Historical Origin
Big Rainbow is an exceptional heirloom variety that represents a true treasure of American family farming heritage. This variety had been cultivated for generations as an heirloom in Polk County, Minnesota, where local families carefully preserved it for decades without a specific name. Its modern documented history began when Dorothy Beiswenger of Crookston, Minnesota, received seeds of this unnamed variety in the early 1980s.
Recognizing the extraordinary qualities of this variety, Dorothy Beiswenger decided to introduce it to the Seed Savers Exchange in 1983, naming it "Big Rainbow" in honor of its spectacular appearance, reminiscent of the colors of a rainbow. The variety remained in preservationist circles until it was first commercially introduced in 1990 by the Southern Exposure Seed Exchange, marking its entry into the commercial heirloom seed market.
Curiosities of Variety
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Anonymous family heirloom : Cultivated for generations in Minnesota with no official name until 1983
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Descriptive Name : Named "Big Rainbow" by Dorothy Beiswenger in direct reference to its multi-colored appearance
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Late introduction : Despite its age, it was not marketed until 1990
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Family Preservation : Kept alive exclusively by Polk County families for decades
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Colorful Giant : Can reach up to 2 lbs (900g) with unique color patterns
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Perfumed taste : Described as having an almost "perfumed" taste due to its exceptional sweetness
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Brotherly Confusion : Often confused with the "Hillbilly" variety due to its similar coloration
Cultural Importance
Big Rainbow represents the essence of family seed preservation in the American Midwest and the critical importance of the Seed Savers Exchange in conserving endangered varieties. This variety exemplifies how rural families have been the true guardians of genetic diversity, preserving unique varieties for generations without formal recognition. Its "rescue" by Dorothy Beiswenger and subsequent introduction to the horticultural world demonstrate the invaluable value of documenting and preserving these family heirlooms before they are lost forever.
1. PLANT DESCRIPTORS
Feature |
Evaluation for "Big Rainbow" |
Type of growth |
Indeterminate |
Growth habit |
Erect and expansive |
Plant height |
Tall (180-200 cm) |
Plant vigor |
Very strong |
Color of young stem |
Green |
Pubescence of the stem |
Present |
Hair density |
Dense ("hairy" plants) |
Leaf type |
Regular (not potato type) |
Leaf color |
Dark green |
Leaflet shape |
Regular (normal sheet) |
Leaflet edge |
Jagged |
Leaf pubescence |
Very present |
3. FRUIT DESCRIPTORS
Feature |
Evaluation for "Big Rainbow" |
Fruit shape |
Oblato - Ribbed Beefsteak |
Fruit weight |
Very large (450-900 g) |
Fruit diameter |
Very large (>10 cm) |
Color of unripe fruit |
Green with green shoulders |
Color of ripe fruit |
Golden yellow with red stripes and spots |
Color intensity |
Very intense |
Color uniformity |
Distinctive two-tone pattern |
Presence of green shoulders |
Present |
Shoulder shape |
Soft ribbed |
Surface smoothness |
Smooth with marked grooves |
Presence of ribs |
Marked and wavy |
Fruit shine |
Bright |
Chalice scar |
Big |
Pistil scar |
Starry |
Number of locules |
6-8 |
Distribution of locules |
Regular |
Thickness of the walls |
Very thick (>8 mm) |
Firmness of the pulp |
Firm and fleshy |
Pulp color |
Golden-yellow with intense red veins |
Amount of juice |
Very juicy |
Quantity of seeds |
Few (<35) |
6. AGRONOMIC CHARACTERISTICS
Feature |
Evaluation for "Big Rainbow" |
Days to flowering |
Late (75-85) |
Days to harvest |
Late (82-90 days from transplant) |
Yield per plant |
Tall (5-7 kg) |
Number of fruits per plant |
Medium (8-15) |
Harvest concentration |
Staggered (mid- to late season) |
Heat tolerance |
Good |
Cold tolerance |
Low |
Low light adaptation |
Regular |
Recommended spacing |
75-90 cm between plants |
7. RESISTANCES AND TOLERANCES
Pathogen/Pest |
Evaluation for "Big Rainbow" |
Alternaria (Alternaria solani) |
Moderately resistant |
Fusarium (Fusarium oxysporum) |
Moderately resistant |
Verticillium (Verticillium dahliae) |
Moderately resistant |
Mildew (Phytophthora infestans) |
Susceptible |
Bacterial wilt (Ralstonia solanacearum) |
Susceptible |
Bacterial freckle (Pseudomonas syringae) |
Susceptible |
Tomato mosaic virus (ToMV) |
Susceptible |
Yellow leaf curl virus (TYLCV) |
Susceptible |
Whitefly (Bemisia tabaci) |
Susceptible |
Trips (Thrips tabaci) |
Susceptible |
Aphids |
Susceptible |
Cracking |
Susceptible |
SPECIAL CHARACTERISTICS OF THE "BIG RAINBOW" VARIETY
Featured Attributes:
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Unique visual spectacle : Each slice is a work of art with golden-yellow colors and dramatic red splashes
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Exceptional flavor : Sweet, smooth and fruity flavor with balanced acidity, described as almost "perfumed"
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Impressive size : Gigantic fruits weighing up to 2 pounds that can completely cover a slice of bread
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Authentic Family Heirloom : A true family heirloom preserved for generations in Minnesota
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Low acidity : Ideal for people with sensitive stomachs due to its mildness
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Late yield : Excellent producer despite its late ripening
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Historical Value : Included in "100 Heirloom Tomatoes for the American Garden" by Carolyn J. Male
Limitations:
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Very late season : Requires long growing season for full development
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Cold sensitivity : Does not tolerate cold temperatures and should be grown in warm conditions
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Susceptibility to cracking : Prone to cracking, especially with humidity fluctuations
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Need for massive support : Requires very strong support structures due to the weight of the fruit.
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Limited availability : Hard to find as seedlings in garden centers
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Gentle handling : Large fruits require careful handling during harvesting.
Recommended Uses:
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Family Heritage Preservation : Essential to preserving this authentic Minnesota family heirloom
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Premium fresh consumption : Exceptional for slicing into gourmet sandwiches and hamburgers
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Food displays : Perfect for presentations where visual impact is key
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Artistic salads : Ideal for caprese salads and dishes where each slice is the star
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Midwest Collecting : A must for collectors of Midwestern American varieties
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Artisanal preserves : Excellent for sauces and preserves due to its sweet flavor and meaty texture.
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Preservation Education : Perfect tool for teaching the importance of the Seed Savers Exchange
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Farmers markets : Ideal to stand out for their beauty and exceptional size
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Culinary photography : Perfect for food photography due to its spectacular colors
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Genetic research : Valuable for studies on bicolor varieties and gigantism in tomatoes
Data based on Seed Savers Exchange documentation, Dorothy Beiswenger records, Southern Exposure Seed Exchange information, Tatiana's TOMATOBase archive, and testimonials from growers specializing in Midwestern varieties.