Marnouar (F1) Tomato Seed

Scientific name

Solanum lycopersicum

Why grow under cover

A high tunnel or greenhouse gives you more control over fruit quality and stretches the season at both ends. Culture is much like field tomatoes, but transplants are usually started earlier, may need an extra week or so (about 6–7 weeks in all) and benefit from supplemental light to stay stocky.

Days to maturity

Counted from transplanting.

Planting

Allow roughly 4–6 sq. ft. per leader, depending on variety, climate, disease pressure and how you prune. Set ungrafted plants deep, as in the field; keep the graft union of grafted plants above the soil line. For the first 5–7 days, hold about 73–77°F (23–25°C) day and night to push new roots and leaves, then drop nights to about 62–66°F (17–19°C) once fruit sets. Under cover, try to keep nights above 55°F and vent on warm days.

Trellising and pruning

Grow each plant on one or two leaders, each clipped to its own vertical string about every third leaf, and keep the strings snug. In a long season with a sturdy structure, a lower-and-lean system keeps fruit within reach. Removing suckers, lower leaves and surplus clusters improves airflow and steers the plant toward fruit. On grafted plants, remove any roots from the scion and any shoots from the rootstock.

Pests and disease

Tunnels and greenhouses bring a somewhat different set of pests than the field, with whiteflies and aphids often worse, but the same management principles apply. Beneficial insects and grafted plants tend to work better under cover than outdoors. Humidity-driven diseases can build up quickly, so ventilate well.

Harvest and storage

As for field tomatoes; whole trusses can also be cut at once.

Transplants

Plan on about 950 plants per 1,000 seeds.

Packet

15 seeds.

Seeds per lb.

About 216,000 on average.