How to Grow Jefferson Tomato

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Jefferson Tomato

Solanum lycopersicum 'Jefferson'

vegetable

Jefferson is a determinate (bush-type) heirloom tomato variety known for its large, flavorful red fruits and disease resistance. It was developed at Cornell University and is particularly valued for its tolerance to early blight and other fungal diseases. The plants are compact and productive, making them suitable for both home gardens and commercial cultivation.

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Example Jefferson Tomato timeline · Pittsburgh, PA (Zone 6b)

Plant Jefferson Tomato
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
Harvest Jefferson Tomato
Around Jun 26

≈ 70 days after planting

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Growing Conditions

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Sun: Full sun, 6-8 hours daily minimum; 8+ hours preferred for best fruit development

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Water: Consistent moisture is critical; water deeply 1-2 inches per week, keeping soil consistently moist but not waterlogged. Water at soil level to prevent fungal issues. More frequent watering during hot, dry spells and when fruit is setting.

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Spacing: 24 inches

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Days to maturity: 70-85 days from transplant to first ripe fruit

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Planting depth: Start seeds ¼ inch deep indoors; transplant so buried stem is up to the first true leaves (6-8 inches deep outdoors)

Soil

Type: Well-draining loamy soil rich in organic matter

pH: 6.0-6.8

Amendments:

Compost Aged manure Peat moss or coconut coir Bone meal for phosphorus Balanced fertilizer (5-10-10)

Growing Zones

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Thrives in zones 3-10; best in zones 5-8 for optimal flavor and disease management

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

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Growth Stages

Seedling

2-3 weeks

Small plants with 2-4 true leaves, pale green to dark green coloring

Provide bright light 14-16 hours daily under grow lights. Keep soil moist but not soggy. Maintain 65-75°F temperatures. Thin to strongest seedlings.

Vegetative Growth

3-4 weeks

Plants develop multiple sets of true leaves, begin branching, and grow 6-12 inches tall. Compact determinate growth habit is visible.

Harden off seedlings gradually before transplanting. Transplant outdoors 2-3 weeks after last frost. Space 24 inches apart. Provide support cages or stakes early. Remove lower leaves as plant grows to improve air circulation.

Flowering

2-3 weeks

Yellow flowers appear in clusters (racemes) along the main stem and branches. Plants may be 18-24 inches tall.

Maintain consistent watering to prevent blossom-end rot and flower drop. Provide balanced fertilizer (5-10-10) every 2-3 weeks. Prune suckers on determinate varieties sparingly. Ensure good air circulation to prevent disease.

Fruiting & Development

3-4 weeks

Green fruits develop and enlarge from the flower clusters. Fruits are typically large (6-8 oz), round, and begin color break from green to red at the bottom.

Continue consistent watering; irregular watering causes cracking and blossom-end rot. Apply mulch to regulate soil moisture and temperature. Monitor for early blight and remove affected lower leaves. Support heavy fruit with additional stakes or slings if needed.

Ripening & Harvest

2-3 weeks per flush

Fruits transition from pink-red to full deep red color. Skin becomes glossy and fruits feel slightly soft when gently squeezed.

Harvest when fully red for best flavor, or pick at the "breaker stage" (first blush of color) if disease pressure is high. Pick regularly to encourage continued production. Cease watering slightly to concentrate flavors in final weeks.

Companion Planting

Plan your garden →

Plant with:

Basil Parsley Carrot Onion Garlic Marigold Nasturtium Borage

Avoid planting near:

Fennel Dill Brassicas (cabbage, broccoli) Potatoes Corn

Common Pests

Prune lower leaves, improve air circulation, mulch to prevent soil splash, apply copper fungicide at first signs, rotate crops yearly
Hand-pick regularly, encourage predatory wasps, use Bacillus thuringiensis (Bt), neem oil spray
Increase humidity, spray with strong water stream, use insecticidal soap, apply neem oil
Yellow sticky traps, spray neem oil, insecticidal soap, encourage beneficial insects
Remove affected leaves, improve air circulation, avoid overhead watering, apply copper fungicide, sanitize tools between plants

Uses

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Fresh slicing and cooking

Culinary

Jefferson tomatoes are large enough for slicing and have excellent flavor suitable for fresh eating, salads, and cooked sauces. Their disease-resistant properties make them reliable producers for consistent harvest throughout the season. [source]

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Sauce and preservation

Culinary

The high sugar content and robust flavor make Jefferson ideal for making tomato sauce, passata, and canned products. Their meaty texture holds up well during cooking and processing. [source]

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Lycopene-rich nutrition

Medicinal

Jefferson tomatoes contain lycopene, a powerful antioxidant associated with heart health and cancer prevention. The lycopene content increases with ripeness and cooking. [source]

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Disease-resistant breeding

Household

Jefferson was specifically bred at Cornell for disease resistance, making it an excellent choice for organic gardeners and those dealing with fungal pressure, reducing the need for chemical interventions. [source]

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Pollinator and beneficial insect support

Wildlife

Tomato flowers attract bees and other pollinators, supporting garden biodiversity. The determinate growth habit allows good air circulation for beneficial insects. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Pick tomatoes when fully red and slightly yielding to gentle pressure for maximum flavor. Harvest in early morning when fruit is cool. For longer storage, pick at the breaker stage (first color change from green to pink-red) and ripen at room temperature. Jefferson is a determinate variety that produces most fruit within a concentrated 2-3 week window, so check plants daily during peak season. Remove entire plants once production ceases.

Fun Facts

🌱 Jefferson tomato was bred at Cornell University's breeding program and was specifically selected for resistance to early blight, a devastating fungal disease common in humid climates—making it one of the most disease-resistant heirloom varieties available.
🌱 As a determinate (bush) variety, Jefferson produces most of its fruit within a 2-3 week window, making it ideal for canning and preservation rather than continuous harvesting like indeterminate varieties.
🌱 The variety is named after Thomas Jefferson, the 3rd U.S. President, who was an accomplished gardener and maintained extensive vegetable gardens at Monticello, growing over 250 varieties of vegetables during his lifetime.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Full Sun Heirloom Mulch Sucker Transplant True Leaves

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