How to Grow Sapphire Gem Tomato

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Sapphire Gem Tomato

Solanum lycopersicum 'Sapphire Gem'

vegetable

Sapphire Gem is a compact, ornamental tomato variety that produces small, deep purple-blue fruits with a sweet flavor. This determinate dwarf cultivar reaches only 12-18 inches tall, making it ideal for containers, hanging baskets, and small spaces. The striking dark fruits contain high levels of anthocyanins, giving them both visual appeal and nutritional value.

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

Plant Sapphire Gem Tomato
Around Apr 17

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

Watering, feeding, and pest-watch reminders.
Harvest Sapphire Gem Tomato
Around Jun 21

≈ 65 days after planting

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

Growing Conditions

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Sun: Full sun, 6-8 hours daily minimum (8+ hours ideal for fruit color development)

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Water: Consistent moisture; water deeply 1-2 inches per week. Keep soil evenly moist but not waterlogged. Container plants may need daily watering in hot weather. Avoid wetting foliage to prevent disease.

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Spacing: 12-18 inches

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Days to maturity: 65-75

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Planting depth: 0.25 inches for seeds; bury transplant stem up to first true leaves

Soil

Type: Well-draining loamy soil rich in organic matter

pH: 6.0-6.8

Amendments:

compost aged manure perlite for container growing balanced fertilizer (5-10-10)

Growing Zones

Find your zone →

Thrives in zones 3-11 as an annual; grown as perennial in zones 10-11

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b

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Growth Stages

Seedling

2-3 weeks

Tiny seedlings with cotyledons (seed leaves) emerge; true leaves begin developing within 1-2 weeks

Keep soil consistently moist but not waterlogged. Provide bright light 14-16 hours daily under grow lights placed 2-3 inches above seedlings. Maintain temperature 70-75°F. Begin fertilizing with half-strength liquid fertilizer once true leaves appear.

Vegetative

3-4 weeks

Plant develops sturdy stem and multiple sets of true leaves; growth is compact and bushy due to determinate nature

Gradually acclimate seedlings to outdoor conditions (hardening off) over 7-10 days before transplanting. Plant after last frost when soil is 60°F or warmer. Support with small cage or stake if needed. Pinch off lower leaves as plant grows to improve air circulation.

Flowering

2-3 weeks

Small yellow flowers appear along the main stem and lateral branches; plant reaches full compact height of 12-18 inches

Maintain consistent watering and provide balanced fertilizer every 2 weeks. Ensure adequate sunlight for good fruit set. Pollinate flowers gently with a small brush if growing indoors or in low-pollinator areas. Remove any diseased or yellowing lower leaves.

Fruiting

4-6 weeks

Green fruits develop and gradually change to deep purple-blue color; typically produce 20-50+ small fruits per plant

Increase potassium fertilizer (lower nitrogen) to promote fruiting and color development. Consistent watering is critical to prevent cracking and blossom-end rot. Morning watering is best. Ensure 6-8+ hours of direct sunlight daily for deep blue coloration. Thin excessive fruit if needed for larger individual fruits.

Harvest

3-8 weeks (depending on climate)

Fruits reach full deep purple-blue color and soften slightly when ripe; may retain green shoulder at top (normal for variety)

Harvest when fruits are fully colored and slightly soft to touch. Ripe fruits pull off easily. Leave fruits on plant for maximum sweetness if weather permits. Continue watering and fertilizing to extend harvest. Plants in ideal conditions may produce through frost.

Companion Planting

Plan your garden →

Plant with:

basil parsley carrot onion marigold borage nasturtium

Avoid planting near:

brassicas (cabbage, broccoli) fennel kohlrabi dill

Common Pests

Hand-pick from plant. Use Bacillus thuringiensis (Bt) spray. Encourage parasitic wasps. Monitor regularly.
Spray with insecticidal soap or neem oil. Use yellow sticky traps. Increase air circulation. Remove affected leaves.
Increase humidity and air circulation. Spray with water forcefully. Use miticide if severe. Neem oil effective in early stages.
Remove infected lower leaves. Improve air circulation. Mulch to prevent soil splash. Use copper or sulfur fungicide preventatively.
Use resistant varieties when possible. Avoid overwatering. Improve drainage. Remove infected plants. Rotate crops.

Uses

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Fresh eating and garnish

Culinary

Sapphire Gem tomatoes have a sweet, mild flavor and are perfect for eating fresh, slicing into salads, or using as an eye-catching garnish. The small size (cherry to grape tomato) makes them ideal for snacking directly from the plant or adding whole to dishes. [source]

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Sauce and preservation

Culinary

Though small, abundant harvests can be combined to make tomato sauce, paste, or preserved products. The deep color carries through in cooked preparations, creating visually striking sauces. [source]

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Anthocyanin source

Medicinal

Sapphire Gem tomatoes are notably high in anthocyanins (purple pigments with antioxidant properties) compared to red tomatoes. These compounds are associated with anti-inflammatory and cardiovascular health benefits. [source]

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Container and ornamental gardening

Household

The ultra-compact size and striking deep purple fruits make Sapphire Gem an excellent choice for decorative container gardens, patio planters, hanging baskets, and small-space gardening. It doubles as both productive plant and ornamental accent. [source]

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Photography and garden display

Craft

The unique deep blue-purple color makes these tomatoes excellent subjects for garden photography, food styling, and ornamental display. The visual uniqueness appeals to gardeners seeking unusual and photogenic varieties. [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 deep purple-blue color, typically 65-75 days after transplanting. Fruits are ripe when they give slightly to gentle pressure. Leave a small stem attached. Harvest regularly to encourage continued production. For best flavor and sweetness, pick fully ripe fruits. Green fruits can be harvested at end of season and ripened indoors at room temperature (60-70°F).

Fun Facts

🌱 Sapphire Gem is one of the few naturally blue tomato varieties, developed through traditional breeding rather than genetic modification, with the deep color coming from high anthocyanin content.
🌱 The variety was developed by plant breeders at Oregon State University and released commercially in the early 2010s as part of their work on pigmented tomatoes.
🌱 Despite their small size, Sapphire Gem plants are incredibly prolific, often producing 30-50+ fruits per compact plant, making them excellent for maximizing yield in container or space-limited gardens.

Gardening Terms

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

Cultivar Full Sun Hardening Off pH Transplant True Leaves

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