San Marzano, Tomato Seeds

San Marzano Tomato Seed

World-famous Italian sauce tomatoes contain abundant solids
Low-acid plum fruit resists cracking and stores well
Vigorous vines carry clusters of intensely red tomatoes
Dense flesh excels in paste, purée, and canning

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Key Attributes

Botanical Name

Solanum lycopersicum

Days to maturity

80 Days

Sun

Full Sun

Packet

50 Seeds

About San Marzano, Tomato Seed, Tomato Seed

The San Marzano Tomato is an easy to grow, heirloom that is known as one of the best tomato 'sauce' varieties in the world! This tomato has a plum shape and is considered by many chefs to be the best sauce and cooking tomato types in the world. These heritage tomatoes are named after the region of San Marzano near Naples, Italy.

Growing details

Planting

Sow Depth

1/16"

Days to Germination

5–10 days

In-row plant spacing

24-36"

Row Spacing

32-48"

Plant profile

Maturity

Summer, Fall

Life Cycle

Annual

Plant Height

72 inches

Growth Habits

Indeterminate

Type

ROMA TOMATOES

Seed & variety

Seeds Per Ounce

9,375

Color

Purple, Red

Seed Type

Heirloom

Growing Season

Warm-Season Crop

Before Planting

Prepare for Tomato by selecting a full-sun, warm site with fertile, well-drained soil and good air circulation. Incorporate compost and adjust nutrients and pH according to a soil test, avoiding excessive nitrogen. Wait until frost danger has passed and the soil has warmed; harden transplants and install supports before planting when the crop requires them.

Planting

Start tomato seed indoors 6–8 weeks before the last expected spring frost, maintaining about 70–80°F until germination. After emergence, provide strong light and slightly cooler conditions to produce sturdy seedlings. Harden plants gradually and transplant after frost danger has passed and soil is at least 60°F. Set nongrafted transplants deeply; keep graft unions above the soil.

Watering

Provide 1–1½ inches of water weekly, keeping moisture consistent during flowering and fruit development. Water deeply at soil level to reduce fruit splitting, blossom-end rot, and foliage disease.

Fertilizer

Side-dress with a balanced vegetable fertilizer after plants establish and again when fruit begins forming. Avoid excessive nitrogen, which promotes foliage at the expense of flowers and fruit.

Harvesting

Harvest tomatoes when fruit reaches its expected size and full variety color and feels firm with a slight give. Twist gently or cut the stem to avoid damaging vines. Pick regularly to encourage continued production.

Tips

Install cages or stakes before plants become large, and mulch after the soil warms. Avoid aggressive pruning on determinate varieties. Protect blossoms from temperature extremes, which can reduce fruit set.

Pests & Diseases

Early and late blights, Septoria leaf spot, bacterial spot or canker, Fusarium and Verticillium wilts, and viruses affect tomatoes. Choose resistant varieties, rotate nightshades, mulch against soil splash, and stake plants. Remove incurably wilted or mosaic plants; discard fruit with expanding lesions rather than composting it.

Watch for hornworms, aphids, flea beetles, cutworms, and whiteflies. Inspect leaf undersides, handpick large caterpillars, use collars around young plants, and encourage beneficial insects before applying a labeled treatment.