How to Grow German Johnson
Solanum lycopersicum
German Johnson is a classic heirloom tomato prized for its rich flavor and historic significance. Gardeners value this variety for its reliable performance in warm conditions, though it requires attentive care to thrive.
📷 Wikipedia: TomatoStarting German Johnson: indoors or direct sow?
🏠 Start indoors 4 weeks before your last spring frost, then move the seedlings outside.
Transplant hardened seedlings outdoors only after the last frost date has passed and soil temperatures have warmed sufficiently.
Soil, care & harvest
Prepare loose, fertile soil with a pH between 6.2 and 6.8 before starting seeds indoors. Sow seeds about one inch deep since they take seven to fourteen days to germinate. Start these seedlings four to six weeks before your last expected frost date so they are ready for planting once the threat of cold passes.
Space plants thirty-six to forty-eight inches apart and provide sturdy cages or trellises for support, as heights vary from one to ten feet. Maintain consistent moisture with deep watering, applying mulch around the base to retain soil humidity. Feed regularly with a balanced fertilizer to sustain heavy fruit production throughout the season.
Watch for tomato hornworms, cutworms, aphids, and tobacco budworm; inspect leaves frequently and remove pests by hand or use organic sprays. Prevent late blight, early blight, septoria leaf spot, and bacterial wilt through good air circulation and avoiding overhead watering. Harvest ripe fruit approximately seventy-five days after transplanting when the color is uniform.
When to Plant German Johnson
Planting windows vary by USDA hardiness zone. Look up yours by ZIP code.
| Zone | Start Indoors | Direct Sow | Harvest |
|---|---|---|---|
| Zone 1 | May | — | October – August |
| Zone 2 | April – May | — | September |
| Zone 3 | April | — | September – October |
| Zone 4 | March – April | — | September – October |
| Zone 5 | March | — | August – October |
| Zone 6 | March | — | August – October |
| Zone 7 | February – March | — | July – September |
| Zone 8 | February | — | July – September |
| Zone 9 | January | — | June – August |
| Zone 10 | January | — | May – July |
| Zone 11 | January | — | April – June |
| Zone 12 | January | — | April – June |
| Zone 13 | January | — | April – June |
Companion Plants for German Johnson
✓ Good companions
Repels aphids, whiteflies, and hornworms while potentially improving tomato flavor
Attracts pollinators and beneficial insects while deterring hornworms
Loosens soil for tomato roots and doesn't compete for nutrients
Repels aphids and may help prevent fungal diseases
Provides ground cover and utilizes space efficiently without competing
Deters nematodes, aphids, and whiteflies with natural compounds
Acts as trap crop for aphids and cucumber beetles
Attracts beneficial insects like parasitic wasps that control tomato pests
✗ Keep away from
Produces juglone toxin that causes tomato wilt and stunted growth
Competes heavily for nutrients and may stunt tomato growth
Both attract corn earworm/tomato fruitworm, increasing pest pressure
Inhibits tomato growth through allelopathic compounds
Nutrition Facts
Per 100g serving (USDA FoodData Central)
