San Marzano Tomato (Solanum lycopersicum 'San Marzano')

San Marzano Tomato

Solanum lycopersicum 'San Marzano'

Its oblong fruits hold sun-ripened sweetness, a staple of Italian cuisine. Heirloom determinate tomato cultivar.

Full sun
2–3/week
Beginner
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Plant Needs

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Sunlight Full direct sunlight for optimal fruiting; tolerate partial shade but may reduce yield and fruit sweetness
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Watering Keep soil consistently moist but not waterlogged; water at the base to avoid wetting foliage and prevent fungal diseases
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Temperature Thrives at 20–28°C; avoid temperatures below 10°C, which will stunt growth and prevent fruiting
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Characteristics

  • Leaf: Compound pinnate leaves with serrated margins, fuzzy green foliage
  • Fruit: Oblong, red, meaty tomatoes with few seeds, 8–12 cm long
  • Flower: Small, yellow, star-shaped blooms in terminal clusters
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Care Guide

Watering

Keep soil evenly moist; water deeply 2–3 times per week, adjusting for rainfall

Fertilization

Apply balanced liquid fertilizer every 2 weeks during vegetative growth. Avoid over-fertilizing with nitrogen, which promotes foliage growth over fruit production

Banana peel compost tea:Steep fully composted banana peels in water for 3 days, dilute 1:20 with water for root drenching; avoid raw peels to prevent pest infestations
Pruning
  • Remove suckers (side shoots) to focus energy on main stem fruit production
  • Trim yellowing lower leaves to improve airflow and reduce fungal disease risk
  • Harvest ripe fruits regularly to encourage continued fruiting throughout the season
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Leaves and stems contain solanine, which may cause vomiting, diarrhea, or lethargy if ingested; ripe fruit is non-toxic

Humans: Ripe fruit is safe for consumption; leaves and stems contain low levels of solanine, which may cause mild gastrointestinal upset if ingested in large quantities

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Garden Uses & Culture

Culture: Prized as a heritage Italian cultivar, associated with authentic Neapolitan pizza sauce

Usage: Culinary use for tomato sauces, pastes, and fresh eating; ornamental edible garden plant