How to Grow Tresco Purple

Wikimedia Commons

Tresco Purple

Solanum lycopersicum 'Tresco Purple'

vegetable

Tresco Purple is an indeterminate heirloom tomato variety known for its deep purple-black fruit with rich, complex flavor. The plant produces medium-sized fruits (3-4 oz) with a meaty texture and excellent taste. It's a vigorous grower that requires staking and pruning for optimal productivity.

When should you plant Tresco Purple in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Tresco Purple timeline →

Example Tresco Purple timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Tresco Purple

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Tresco Purple

    Around Jul 1

    ≈ 75 days after planting

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

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily minimum (8+ hours preferred for best flavor)
💧
Water: Consistent deep watering, 1-2 inches per week; keep soil evenly moist but not waterlogged. Water at the base to avoid foliar diseases.
📏
Spacing: 24 inches
📅
Days to maturity: 75-85 days from transplanting
🌱
Planting depth: Start seeds ¼ inch deep indoors; transplant with buried stem up to first true leaves outdoors

Soil

Type: Well-draining loamy soil rich in organic matter
pH: 6.0-6.8
Amendments:
Compost aged manure bone meal potassium-rich fertilizer

Growing Zones

Find your zone →

Thrives in zones 5-9, can be grown in zone 4 with season extension

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

Sign up free to see if Tresco Purple grows in your zone — and get a personalized planting timeline.

Get my Tresco Purple timeline →

Growth Stages

1

Seedling

2-3 weeks

Small plants with cotyledons and developing true leaves, 2-4 inches tall

Maintain consistent moisture and warmth (70-75°F). Provide bright light 12-16 hours daily. Thin to strongest seedlings.

2

Vegetative Growth

3-4 weeks

Rapid stem and leaf development after transplanting; plant grows 12-24 inches tall with multiple branches

Install stakes or cages early. Begin light pruning to remove lower leaves and suckers. Keep soil consistently moist.

3

Flowering

3-4 weeks

Yellow flower clusters (inflorescences) appear at leaf axils; plant may reach 4-6 feet or taller

Maintain steady watering and moderate nitrogen fertilizer. Continue removing suckers. Pinch off excessive foliage above flower clusters for air circulation.

4

Fruiting

4-6 weeks

Green fruits develop at flower sites, gradually enlarging and turning deep purple-black as they ripen

Reduce nitrogen, increase potassium and phosphorus. Prune upper foliage only to expose developing fruit to light. Support heavy fruit clusters.

5

Harvest & Extended Production

6-8 weeks or until frost

Ripe purple-black fruits ready for picking; plant continues flowering and fruiting in warm climates

Harvest when fully colored but still firm. Continue watering and fertilizing. Monitor for disease and pests as season progresses.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Brassicas Fennel Potatoes Cabbage Kohlrabi

Common Pests

  • Hand-pick in early morning; encourage parasitic wasps; apply Bacillus thuringiensis (Bt) if infestation is heavy

  • Spray with insecticidal soap or neem oil; yellow sticky traps; encourage natural predators

  • Increase humidity; spray with water; use miticide if severe; neem oil application

  • Remove infected lower leaves; improve air circulation; avoid wetting foliage; mulch to prevent soil splash; apply copper fungicide if needed

  • Ensure good drainage; avoid overhead watering; remove infected foliage promptly; apply copper or chlorothalonil fungicide in humid conditions

Uses

🍳

Fresh eating & salads

Culinary

Tresco Purple tomatoes have a complex, rich flavor with sweet and savory notes that make them excellent for fresh slicing, salads, and eating raw. The meaty texture and low seed content make them ideal for culinary use. [source]

🍳

Sauce & cooking

Culinary

The concentrated flavor of Tresco Purple makes it superb for tomato sauces, salsas, and cooked dishes. The deep color carries through to finished sauces, creating visually stunning presentations. [source]

💊

Antioxidant benefits

Medicinal

Purple tomatoes are rich in lycopene and anthocyanins, powerful antioxidants associated with reduced inflammation and cardiovascular health. The dark pigmentation indicates high phytonutrient content. [source]

🏠

Home preservation

Household

Tresco Purple can be preserved through canning, freezing, or drying for year-round use. High acidity (pH 4.3-4.9) makes it suitable for water bath canning without added acid. [source]

🎨

Seed saving

Craft

As an heirloom variety, Tresco Purple is excellent for seed saving. Save seeds from fully ripe, healthy fruits, ferment them with juice to remove the gel coating, dry thoroughly, and store in cool conditions for future planting. [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 colored deep purple-black but still slightly firm to the touch. For best flavor development, allow to ripen fully on the vine in warm weather. Tresco Purple can also be picked at the 'breaker stage' (first blush of color) and ripened indoors in cooler climates. Store at room temperature; do not refrigerate as this diminishes flavor.

Fun Facts

  • 🌱 Tresco Purple is named after Tresco Island in the Isles of Scilly off the coast of Cornwall, England, where it was developed by plant breeders for the challenging maritime climate
  • 🌱 The deep purple-black color in tomatoes comes from anthocyanins, the same compounds found in blueberries, and is relatively rare compared to red varieties
  • 🌱 Tresco Purple is an indeterminate variety, meaning it continues to grow and produce fruit until frost, making it highly productive in long growing seasons but requiring consistent pruning and support

Gardening Terms

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

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Tresco Purple planting timeline

Tell us your zip code and we'll calculate exactly when to start Tresco Purple seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Tresco Purple timeline →