Wisconsin 55
Solanum lycopersicum 'Wisconsin 55'
A cold-hardy heirloom developed at the University of Wisconsin for short growing seasons and cooler climates. This early-maturing variety produces flavorful, medium-sized fruits even when nighttime temperatures dip low, making it perfect for Northern gardeners and high-altitude locations where the growing season is limited.
Harvest
75-80d
Days to harvest
Sun
Blossom-End Rot of Tomato
Zones
10–9
USDA hardiness
Height
1-10 feet
Planting Timeline
Showing dates for Wisconsin 55 in USDA Zone 7
All Zone 7 tomato →Zone Map
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Wisconsin 55 · Zones 10–9
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 3 | April – April | June – July | — | September – October |
| Zone 4 | March – April | June – June | — | August – October |
| Zone 5 | March – March | May – June | — | August – October |
| Zone 6 | March – March | May – June | — | August – October |
| Zone 7 | February – March | April – May | — | July – September |
| Zone 8 | February – February | April – May | — | July – September |
| Zone 9 | January – January | March – April | — | June – August |
| Zone 10 | January – January | February – March | — | May – July |
Complete Growing Guide
Light: Blossom-End Rot of Tomato, Pepper, and Watermelon. Soil: Clay, High Organic Matter, Loam (Silt), Sand. Soil pH: Acid (<6.0), Neutral (6.0-8.0). Drainage: Good Drainage, Moist. Water: Blossom-End Rot of Tomato, Pepper, and Watermelon. Height: 1 ft. 0 in. - 10 ft. 0 in.. Spread: 1 ft. 0 in. - 4 ft. 0 in.. Spacing: 3 feet-6 feet. Growth rate: Rapid. Maintenance: High. Propagation: Seed. Regions: Coastal, Mountains, Piedmont.
Harvesting
The fruits are smooth, shiny, glossy, and are classified as berries. The size, shape, and color will vary depending on the variety or cultivar. The color of the fruits may be red, yellow, orange, green, purple, or pink. The fruits may contain over 100 yellow to light brown seeds.
Color: Gold/Yellow, Green, Orange, Pink, Purple/Lavender, Red/Burgundy, Variegated. Type: Berry. Length: > 3 inches. Width: > 3 inches.
Garden value: Edible, Showy
Harvest time: Fall, Summer
Bloom time: Fall, Summer
Edibility: The fruits or berries of the tomato are edible. They may be eaten raw, cooked, dried, or processed. They are a rich source of Vitamin A, Vitamin C, folic acid, and antioxidants. Lycopene is an antioxidant that gives the tomato its rich red color. Many plants will drop fruit when ripe or the fruit will come off easily. Tomatoes will continue to ripen once picked. Store them at room temperature.
Storage & Preservation
Fresh Wisconsin 55 tomatoes store exceptionally well compared to many heirloom varieties. Keep ripe fruits at room temperature for 3-5 days for best flavor, then refrigerate for up to one week. Green harvested fruits ripen gradually when stored in a cool basement or garage at 55-65°F.
For preservation, Wisconsin 55's balanced acidity and firm flesh make it excellent for water bath canning – perfect for sauces, whole peeled tomatoes, and salsa. The variety's moderate sugar content prevents excessive caramelization during cooking, maintaining bright tomato flavor in preserved products.
Freeze whole fruits by removing cores and placing in freezer bags – the skins slip off easily after thawing. Wisconsin 55 also dehydrates well due to its lower water content, creating intensely flavored dried tomatoes that store for months in airtight containers.
History & Origin
Wisconsin 55 was developed in the 1940s by researchers at the University of Wisconsin-Madison as part of their pioneering work in cold-climate vegetable breeding. The variety emerged from a systematic breeding program aimed at creating tomatoes that could reliably produce quality fruit in Wisconsin's challenging short-season conditions, where early and late frosts severely limit traditional tomato cultivation.
University breeders selected parent plants based on their ability to set fruit at lower temperatures and ripen quickly, traits that were uncommon in tomato varieties available at the time. The '55' designation refers to the year it was officially released to gardeners and commercial growers.
This variety became a cornerstone of northern gardening, particularly in the Upper Midwest, where it enabled thousands of gardeners to successfully grow tomatoes in previously marginal climates. Wisconsin 55 represents an important milestone in American agricultural development, demonstrating how targeted plant breeding could expand food production into challenging environmental conditions. Today, it remains one of the most reliable short-season varieties available to home gardeners.
Advantages
- +Attracts: Bees, Pollinators, Predatory Insects
- +Wildlife value: The plant is pollinated by bees, especially bumblebees.
- +Edible: The fruits or berries of the tomato are edible. They may be eaten raw, cooked, dried, or processed. They are a rich source of Vitamin A, Vitamin C, folic acid, and antioxidants. Lycopene is an antioxidant that gives the tomato its rich red color. Many plants will drop fruit when ripe or the fruit will come off easily. Tomatoes will continue to ripen once picked. Store them at room temperature.
- +Fast-growing
Considerations
- -Toxic (Leaves, Stems): Medium severity
- -High maintenance
Companion Plants
Plant Together
Basil
Repels aphids, whiteflies, and hornworms while potentially improving tomato flavor
Marigold
Deters nematodes, aphids, and whiteflies with natural compounds
Nasturtium
Acts as trap crop for aphids and cucumber beetles, repels whiteflies
Parsley
Attracts beneficial insects like hoverflies and parasitic wasps
Carrots
Help break up soil and don't compete for nutrients or space
Chives
Repel aphids and may improve tomato growth and flavor
Borage
Repels hornworms and attracts pollinators, may improve tomato taste
Lettuce
Provides ground cover and efficient use of space without competing for nutrients
Keep Apart
Black Walnut
Produces juglone toxin that causes tomato wilt and stunted growth
Fennel
Inhibits growth of tomatoes through allelopathic compounds
Brassicas
Compete for similar nutrients and may stunt tomato growth when planted too close
Corn
Both attract corn earworm/tomato hornworm and compete for nitrogen
Nutrition Facts
Per 100g serving. % Daily Value based on 2,000 calorie diet. Source: USDA FoodData Central (FDC #321360)
Pests & Disease Resistance
Resistance
Good cold tolerance, moderate resistance to common tomato diseases
Common Pests
Colorado potato beetle, aphids, cutworms
Diseases
Late blight in cool, wet conditions, septoria leaf spot