How to Grow German Johnson

Wikimedia Commons

German Johnson

Solanum lycopersicum 'German Johnson'

vegetable

German Johnson is a large beefsteak tomato variety prized for its rich, complex flavor and substantial size. Known for its deep red color, meaty texture, and productive yields, it's a favorite among heirloom tomato growers. This indeterminate variety produces fruit throughout the season and is excellent for fresh eating, slicing, and sauce-making.

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Example German Johnson timeline · Pittsburgh, PA (Zone 6b)

Plant German Johnson
Around Apr 17

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

Watering, feeding, and pest-watch reminders.
Harvest German Johnson
Around Jul 1

≈ 75 days after planting

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

Growing Conditions

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Sun: Full sun, 8+ hours daily; ideally 10-12 hours for optimal fruiting

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Water: Consistent, deep watering 1-2 inches per week; maintain even soil moisture to prevent cracking and blossom end rot. Water at soil level in early morning to reduce disease risk. Increase frequency during fruiting stage.

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Spacing: 24 inches

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Days to maturity: 75-85 days from transplant

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Planting depth: 0.25 inches for seeds; transplant deeply (bury up to first true leaves) to establish strong root system

Soil

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

pH: 6.0-6.8

Amendments:

Compost Aged manure Perlite or coarse sand for drainage Bone meal for phosphorus Calcium source (crushed eggshells, gypsum) to prevent blossom end rot

Growing Zones

Find your zone →

Thrives in zones 5-9; can be grown as annual in cooler zones 3-4 with season extension

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

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Growth Stages

Seedling

6-8 weeks

Small plants with 2-4 true leaves; sturdy green stems developing

Start indoors 6-8 weeks before last frost. Keep soil consistently moist but not waterlogged. Provide bright light 14-16 hours daily. Maintain 65-75°F temperature. Harden off for 7-10 days before transplanting outdoors.

Vegetative Growth

3-4 weeks

Rapid stem and leaf development; plant reaches 12-18 inches tall; no flowers yet

Transplant outdoors after all frost danger passes. Install sturdy cages or stakes immediately. Prune lower leaves after plants are established. Apply mulch (2-3 inches) to regulate soil temperature and moisture. Fertilize every 2-3 weeks with balanced fertilizer.

Flowering

2-3 weeks

Yellow flowers appear in clusters; plant grows vigorously to 4-6 feet tall

Maintain consistent watering; irregular watering causes blossom end rot. Continue supporting with sturdy stakes or cages. Begin pruning suckers (shoots between main stem and branches) on indeterminate plants for better air circulation. Apply calcium and magnesium supplements.

Fruiting & Development

3-4 weeks

Green tomatoes develop rapidly; large fruit (8-12 oz) becomes increasingly heavy on branches

Provide strong support; use clips or soft ties to secure heavy fruit clusters to stakes. Reduce nitrogen fertilizer; increase phosphorus and potassium. Prune excess foliage moderately to improve air circulation and allow fruit exposure to sun. Continue consistent deep watering.

Ripening & Harvest

2-3 weeks per fruit; season-long production

Fruit transitions from green to deep red; develops full flavor and rich aroma

Harvest at full red color for best flavor and juiciness. In late season, pinch off new flowers to redirect energy to existing fruit ripening. Stop pruning 6 weeks before first frost to allow plant to mature fruit. Pick fruit early if frost threatens.

Companion Planting

Plan your garden →

Plant with:

Basil Parsley Carrot Onion Marigold Nasturtium Borage Chamomile Garlic

Avoid planting near:

Brassicas (cabbage, broccoli, cauliflower) Fennel Dill Kohlrabi Potato Other tomato varieties (cross-pollination/disease spread)

Common Pests

Hand-pick daily; use Bacillus thuringiensis (Bt) spray; encourage parasitic wasps; grow dill and parsley as trap crops
Remove infected lower leaves; mulch to prevent soil splash; improve air circulation; use copper or sulfur fungicides; avoid wetting foliage
Remove entire infected plant; apply chlorothalonil or copper fungicide; improve drainage and air flow; avoid overhead watering
Spray with strong water stream; use neem oil or insecticidal soap; release ladybugs; plant alyssum and yarrow nearby
Increase humidity; spray with water; use neem oil or miticide; avoid over-fertilizing with nitrogen
Maintain consistent soil moisture; add calcium (crushed eggshells, gypsum); mulch; avoid excessive nitrogen fertilizer

Uses

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Fresh Slicing & Sandwiches

Culinary

German Johnson's large size, meaty texture, and deep red color make it ideal for thick slices in sandwiches, salads, and fresh eating. The complex, sweet-acidic flavor is superior to most modern commercial varieties. [source]

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Sauce & Preservation

Culinary

The high solids content and rich flavor make German Johnson excellent for homemade tomato sauce, paste, and canning. Its substantial size yields more usable fruit with fewer seeds than smaller varieties. [source]

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Cooking & Heirloom Varieties

Culinary

As a traditional heirloom variety, German Johnson carries historical significance in American gardening. It's prized by culinary enthusiasts for its old-fashioned tomato taste that commercial hybrids often lack. [source]

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Seed Saving

Household

German Johnson is an open-pollinated variety that produces viable seeds for saving. Home gardeners can preserve seeds by fermentation and drying, ensuring a perpetual supply of this heirloom variety. [source]

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Lycopene & Antioxidants

Medicinal

Deep red tomatoes like German Johnson are rich in lycopene, a powerful antioxidant linked to cardiovascular and prostate health. Cooking or processing increases bioavailability of these beneficial compounds. [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 fruit is completely red and yields slightly to gentle pressure. Typically produces 6-10 large fruits per indeterminate plant over the season. Pick regularly to encourage continuous production. Harvest before first frost by picking all fruit at the pink or light red stage and ripening indoors at room temperature (68-72°F). Store at room temperature, never refrigerate, to preserve flavor.

Fun Facts

🌱 German Johnson is an open-pollinated heirloom variety that has been passed down through gardening families for generations, with roots tracing back to German-American farming communities in the United States.
🌱 This variety is indeterminate, meaning it continues growing and producing fruit until frost kills the plant, unlike determinate types that stop after setting one main crop.
🌱 German Johnson tomatoes can reach 12 ounces or more and are known for their superior flavor compared to modern hybrid beefsteaks, making them a favorite in heirloom tomato taste tests and farmers' markets.

Gardening Terms

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

Full Sun Heirloom Mulch pH Sucker Transplant True Leaves

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