How to Grow Potomac Red

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Potomac Red

Solanum lycopersicum 'Potomac Red'

vegetable

Potomac Red is a determinate, early-maturing tomato variety developed for the Mid-Atlantic region, known for its disease resistance and reliable production. It produces medium-sized, globe-shaped red fruits with good flavor and firm texture, making it ideal for fresh eating and processing. This cultivar was bred to withstand regional diseases and environmental challenges.

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Example Potomac Red timeline · Pittsburgh, PA (Zone 6b)

Plant Potomac Red
Around Apr 17

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

Watering, feeding, and pest-watch reminders.
Harvest Potomac Red
Around Jun 21

≈ 65 days after planting

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

Growing Conditions

☀️

Sun: Full sun, 6-8 hours daily minimum

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Water: Consistent moisture of 1-2 inches per week; water deeply at soil level to avoid wetting foliage; more frequent watering during hot, dry periods

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Spacing: 24-36 inches

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Days to maturity: 65-75 days from transplant

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Planting depth: Bury transplants deeply, up to first true leaves; seeds planted 0.25 inches deep

Soil

Type: Well-draining loamy soil rich in organic matter

pH: 6.0-6.8

Amendments:

Compost aged manure balanced fertilizer (5-10-10) bone meal for phosphorus

Growing Zones

Find your zone →

Best suited for USDA zones 5-8, particularly the Mid-Atlantic region

5a 5b 6a 6b 7a 7b 8a 8b

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Growth Stages

Seedling

4-6 weeks

Small plants with 2-4 true leaves; pale green color and delicate stems

Keep soil moist but not waterlogged; provide 14-16 hours of light daily under grow lights; maintain temperature of 70-75°F; thin seedlings to strongest specimens

Transplant Hardening

1-2 weeks before planting

Seedlings develop stronger stems and deeper green color as they acclimate to outdoor conditions

Gradually expose to outdoor light and temperature over 7-10 days; reduce watering slightly to encourage root development; avoid wind stress early on

Vegetative Growth

3-4 weeks

Rapid stem and leaf development; plant reaches 12-24 inches tall with multiple branches and full foliage

Water consistently; apply mulch 2-3 inches thick around base; stake or cage early; remove suckers on determinate varieties if desired; begin fertilizing every 2-3 weeks

Flowering & Fruit Set

2-3 weeks

Yellow flowers appear at leaf axils; small green fruits develop after pollination; plant reaches full size

Maintain consistent watering to prevent blossom end rot; support heavy fruit clusters; reduce nitrogen to encourage fruiting; avoid over-fertilizing which promotes foliage over fruit

Fruiting & Harvest

3-4 weeks, concentrated ripening period

Fruits enlarge and ripen from green to full red color; determinate types concentrate harvest within 2-3 weeks

Water deeply and regularly to maintain fruit quality; continue light fertilization; harvest ripe fruits regularly to encourage more production; monitor for disease and pests

Companion Planting

Plan your garden →

Plant with:

Basil Parsley Carrot Marigold Borage Onion Garlic

Avoid planting near:

Brassicas (cabbage, broccoli, Brussels sprouts) Fennel Corn

Common Pests

Hand-pick caterpillars; use Bacillus thuringiensis (Bt); encourage parasitic wasps; plant dill and parsley for parasitoid wasps
Remove lower leaves as plant grows; improve air circulation; mulch to prevent soil splash; apply copper fungicide; resistant variety helps prevent
Remove infected leaves; avoid overhead watering; apply fungicide; ensure good spacing for air flow; stake plants for better ventilation
Use yellow sticky traps; spray neem oil; encourage beneficial insects; reflective mulch; maintain plant vigor
Increase humidity; spray with water; use neem oil or miticide; remove heavily infested leaves

Uses

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Fresh eating and salads

Culinary

Potomac Red fruits have good flavor and firm texture ideal for slicing fresh in salads and sandwiches. The medium size and reliable quality make it a favorite for home kitchen use. [source]

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Canning and processing

Culinary

As a paste and processing type, Potomac Red is suitable for making tomato sauce, paste, and canned products. Its breeding for the Mid-Atlantic region includes traits for reliable juice content and solids. [source]

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Lycopene-rich antioxidant source

Medicinal

Red tomatoes like Potomac Red are rich in lycopene, a powerful antioxidant associated with cardiovascular and prostate health. Cooking tomatoes increases lycopene bioavailability. [source]

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Disease resistance breeding

Household

Potomac Red was specifically developed for disease resistance in the humid Mid-Atlantic climate, making it valuable as a parent plant in breeding programs. Its traits help gardeners reduce fungicide applications. [source]

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Pollinator and beneficial insect habitat

Wildlife

Tomato flowers attract bees and other pollinators essential for fruit set. The plant's foliage also supports beneficial insects like parasitic wasps that 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

Harvest when fruits are fully red and slightly soft to the touch, typically 70-80 days from planting. Potomac Red is a determinate type, so most fruit ripens within a concentrated 2-3 week window. Pick ripe fruits regularly to encourage continued production. Fruits can be picked at the breaker stage (first blush of color) and ripened indoors if needed. Harvest before first frost in fall.

Fun Facts

🌱 Potomac Red was developed at the University of Maryland specifically to meet the growing and disease challenges of the Mid-Atlantic region, particularly for commercial and home growers in Maryland and nearby states.
🌱 Tomatoes are technically fruits (berries) but are legally classified as vegetables in the U.S. Supreme Court case Tariff Act of 1883, which ruled they should be treated as vegetables for tariff purposes.
🌱 The determinate growth habit of Potomac Red means it stops growing at a predetermined height and produces most fruit in a short window, making it ideal for canning operations and gardeners wanting concentrated harvests.

Gardening Terms

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

Cultivar Full Sun Mulch Pollination Sucker True Leaves

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