How to Grow Kingstone Black
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Kingstone Black
Solanum lycopersicum 'Kingstone Black'
vegetableKingstone Black is a determinate heirloom tomato variety producing deep purple-black fruits with rich, complex flavor. The medium-sized fruits typically weigh 4-6 ounces and have a dark mahogany-black color with slight green shoulders when immature. This variety is prized by heirloom tomato enthusiasts for its distinctive appearance and exceptional taste.
When should you plant Kingstone Black in your zone?
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Example Kingstone Black timeline · Pittsburgh, PA (Zone 6b)
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Plant Kingstone Black
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Kingstone Black
Around Jun 26≈ 70 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Kingstone Black dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-10 as an annual; can be grown in zones 3-4 with season extension techniques
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Seedling
3-4 weeksSmall plants with 2-3 sets of true leaves, 2-4 inches tall
Provide bright light (12-14 hours daily under grow lights), keep soil moist but not waterlogged, maintain 65-75°F, thin if overcrowded
Vegetative Growth
3-4 weeks after transplantRobust growth with multiple stems, 6-12 inches tall at transplant stage; foliage-heavy with deep green leaves
Harden off seedlings over 7-10 days before transplanting; plant deeply in warm soil (60°F+); stake or cage early; pinch suckers if desired; apply balanced fertilizer every 2-3 weeks
Flowering & Fruit Set
4-5 weeksYellow flower clusters appear at leaf axils; small green marble-sized fruits develop after pollination
Maintain consistent watering to prevent blossom-end rot and fruit cracking; switch to lower-nitrogen fertilizer (5-10-10); provide support structure; ensure adequate pollination with air circulation or gentle plant shaking
Fruit Development & Maturation
4-6 weeksFruits enlarge to 4-6 ounces; skin color develops from light green to dark mahogany-black with characteristic depth; interior ripens to deep red
Maintain consistent watering (critical for flavor and preventing cracks); continue support; thin some foliage to allow sun access to ripening fruits; monitor for pests; avoid over-fertilizing nitrogen which delays ripening
Harvest
2-4 weeks peak harvestFully mature fruits display deep black-purple color with slight give when gently squeezed; fully ripe when dark purple-black throughout
Harvest at full color for peak flavor; can pick when mostly colored and finish ripening on windowsill if frost threatens; determinate type produces most fruit over 3-4 week concentrated period
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick daily, encourage parasitic wasps, apply Bacillus thuringiensis (Bt), neem oil
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Yellow sticky traps, insecticidal soap, neem oil, encourage beneficial insects
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Remove infected leaves, improve air circulation, water at soil level only, apply copper fungicide
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Remove lower leaves, mulch soil, avoid overhead watering, apply copper or chlorothalonil fungicide
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Choose resistant varieties if available, remove infected plants, practice crop rotation (3-year minimum), sterilize tools
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Improve air circulation, remove affected leaves, spray with sulfur or neem oil, avoid wetting foliage
Uses
Fresh slicing and gourmet cooking
CulinaryKingstone Black's deep, complex flavor with hints of sweetness and slight earthiness makes it ideal for fresh slicing, salads, and upscale culinary applications. The dramatic dark color provides striking visual presentation on plates. [source]
Sauce and preservation
CulinaryThe rich flavor concentrates beautifully in tomato sauce, paste, and canned preparations. Works well for creating distinctive dark-colored sauces and preserves. [source]
Nutritional benefits
MedicinalDark tomatoes like Kingstone Black contain high levels of anthocyanins and lycopene, powerful antioxidants linked to reduced inflammation and heart health benefits. [source]
Ornamental garden display
CraftThe striking black-purple fruits make this variety attractive for ornamental vegetable gardens and edible landscaping, providing both visual interest and food production. [source]
Pollinator support
WildlifeThe yellow flowers attract bees and other pollinators to the garden, supporting biodiversity while ensuring good fruit set for tomato production. [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 fully black-purple with slight softness to touch (typically 2-3 weeks after first color appears). Kingstone Black is a determinate variety, meaning most fruit ripens within a concentrated 3-4 week window rather than continuously. Harvest in the morning after dew dries. Fruits can be picked when mostly colored and ripened indoors on a sunny windowsill if frost is imminent. Store at room temperature, not refrigerated, to preserve flavor.
Fun Facts
- 🌱 Kingstone Black belongs to the 'Black Krim' family of dark-colored heirloom tomatoes, which originated in Crimea and have become increasingly popular among tomato connoisseurs for their complex, wine-like flavors.
- 🌱 The deep purple-black color comes from high concentrations of anthocyanins, the same powerful antioxidants found in blueberries and blackberries, making black tomatoes a nutritional powerhouse.
- 🌱 Despite their dramatic appearance, black tomatoes are actually not a separate species but rather tomato varieties with concentrated pigmentation; they require full sun exposure to develop their characteristic dark coloration.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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