How to Grow Harmony Tomato

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Harmony Tomato

Solanum lycopersicum 'Harmony'

vegetable

Harmony is a determinate (bush-type) tomato variety known for its disease resistance and reliable production of medium-sized red fruits. It was bred specifically for resistance to early blight, late blight, and verticillium wilt, making it an excellent choice for humid climates. This compact plant is ideal for containers, small gardens, and commercial production.

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

Plant Harmony Tomato
Around Apr 17

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

Watering, feeding, and pest-watch reminders.
Harvest Harmony Tomato
Around Jun 24

≈ 68 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Harmony Tomato dates for your own zip code.

Growing Conditions

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Sun: Full sun, 6-8 hours daily minimum (8+ hours preferred for best fruiting)

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Water: Consistent moisture, approximately 1-1.5 inches per week. Water deeply at soil level to avoid wetting foliage and reducing disease pressure. Keep soil evenly moist but not waterlogged.

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Spacing: 24 inches

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Days to maturity: 68-75 days from transplant to first ripe fruit

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Planting depth: 0.25 inches for seeds; transplants should be buried deeper (up to first true leaves) to encourage root development

Soil

Type: Well-draining, fertile loamy soil rich in organic matter

pH: 6.0-6.8

Amendments:

compost aged manure peat moss or coconut coir bone meal for phosphorus

Growing Zones

Find your zone →

Thrives in zones 5-9, but can be grown in zones 3-10 with appropriate timing and care

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

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Growth Stages

Seedling

2-3 weeks indoors

Tiny plants with cotyledons (seed leaves) developing into first true leaves. Growth is slow initially.

Provide bright light indoors (14-16 hours daily), keep soil consistently moist but not waterlogged, maintain 70-75°F temperature, and fertilize weekly with diluted balanced fertilizer once true leaves appear.

Vegetative

3-4 weeks after transplanting

Plants develop multiple sets of true leaves and sturdy stems. Roots establish rapidly after transplanting outdoors.

Harden off transplants for 7-10 days before planting. Space 24 inches apart. Begin staking or caging early. Prune lower leaves once plant is established. Water consistently and monitor for disease.

Flowering

4-6 weeks

Small yellow flowers appear in clusters (indeterminate growth pattern), typically starting 4-6 weeks after transplanting.

Harmony is determinate, so flowering occurs in waves. Ensure consistent watering and fertilization with balanced or slightly lower nitrogen feed. Support flowering clusters with sturdy cages or stakes. Maintain proper spacing for air circulation.

Fruiting

3-4 weeks from flower to mature green; 2-3 weeks to ripe red

Green fruit develops from flowers and gradually enlarges. Fruits begin color break (turning from green to red/pink) 55-65 days after flowering.

Continue consistent watering—inconsistent moisture causes cracking and blossom-end rot. Reduce nitrogen, increase potassium and phosphorus. Remove some foliage strategically to allow fruit exposure to sunlight without sunscald. Watch for pests and disease.

Harvest

4-8 weeks of continuous harvest

Fruits reach full red color and develop characteristic tomato aroma. As a determinate variety, Harmony produces most fruit within a concentrated 3-4 week window.

Pick fruits at full color for best flavor, or pick mature green fruit and ripen indoors if frost threatens. Harvest regularly to encourage continued production. Remove diseased or cracked fruit immediately.

Companion Planting

Plan your garden →

Plant with:

basil parsley marigold carrot onion borage nasturtium sage

Avoid planting near:

brassicas (cabbage, broccoli) fennel dill kohlrabi potato

Common Pests

Hand-pick or use Bt (Bacillus thuringiensis) spray. Monitor for dark droppings on leaves. Encourage parasitic wasps by planting flowering herbs nearby.
Spray with water to dislodge; use insecticidal soap or neem oil if severe. Increase humidity and avoid over-fertilizing with nitrogen.
Use yellow sticky traps, reflective mulch, or insecticidal soap. Remove heavily infested leaves. Ensure good air circulation.
Spray with water, use insecticidal soap, neem oil, or encourage beneficial insects like ladybugs and lacewings.
Remove affected lower leaves, improve air circulation, water at soil level only, apply copper fungicide if needed. Harmony has good resistance but preventive care is important.
Ensure consistent watering and adequate calcium (add crushed eggshells or bone meal). Mulch to regulate soil moisture.

Uses

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Fresh eating and cooking

Culinary

Harmony tomatoes have good flavor and firm texture, making them suitable for fresh eating, slicing, and cooking. They are particularly prized for sauce and paste production due to their concentrated flavor and determinate ripening pattern. [source]

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Canning and preservation

Culinary

As a determinate variety, Harmony produces most fruit simultaneously, making it ideal for bulk processing, canning, freezing, and sauce-making. The consistent ripening is perfect for home preservation projects. [source]

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Lycopene and antioxidant source

Medicinal

Tomatoes contain lycopene, a powerful antioxidant linked to cardiovascular and bone health. Cooking tomatoes increases lycopene bioavailability, making cooked Harmony tomatoes a nutritious addition to sauces and soups. [source]

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Disease-resistant gardening

Household

Harmony's resistance to early blight, late blight, and verticillium wilt makes it an excellent choice for organic and sustainable gardening approaches, reducing the need for fungicide applications. [source]

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Pollinator and beneficial insect support

Wildlife

Tomato flowers attract pollinators and beneficial insects. Growing Harmony alongside flowering herbs creates a habitat for bees, hoverflies, and parasitic wasps that help control pest populations. [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 fruits when they reach full red color. Harmony is determinate, so most fruit ripens within 2-3 weeks, making it ideal for canning and sauce-making. For longer harvest, plant in succession every 2-3 weeks. Fruits can be picked at mature green stage and ripened indoors if needed before frost. Twist gently or use pruning shears to avoid damaging the plant.

Fun Facts

🌱 Harmony was developed through traditional breeding to combine disease resistance with reliable production, making it one of the most disease-resistant determinate varieties available for home gardeners.
🌱 Determinate tomatoes like Harmony have a genetically programmed end to their growing season, causing the plant to stop growing and focus all energy on producing fruit within a concentrated timeframe—perfect for simultaneous ripening needed for canning.
🌱 Burying tomato transplants deeper than they were growing encourages additional roots along the buried stem, creating a stronger root system that can access more water and nutrients throughout the growing season.

Gardening Terms

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

Full Sun pH Transplant True Leaves

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