Tomato Greenhouse Growing Guide

Tomato is the benchmark protected crop: high yielding, well understood and unforgiving of a facility that was specified too cheaply. Modern high-wire production requires vertical space, light, humidity control and CO₂. A facility missing any of these will produce tomatoes, but not at the yields the business case assumed.

• Gutter height of 6.0 m or more for high-wire canopy volume
• High light transmission — diffuse glass where capital allows
• Energy screens for humidity and heat management
• CO₂ dosing, ideally recovered from heating exhaust
• Substrate hydroponics with drain collection and recirculation

Tomato climate management balances vegetative and generative development through temperature strategy rather than holding a fixed set point. The 24-hour average temperature drives development rate, while the day-night differential steers the plant between growth and fruit setting.

• Day temperature: 21 – 24 °C depending on light level
• Night temperature: 16 – 18 °C
• 24-hour average: 19 – 21 °C as the primary steering figure
• Relative humidity: 70 – 85%, managed by deficit rather than absolute value
• CO₂: 800 – 1,000 ppm when ventilation permits

High-wire systems train plants on vertical strings and lower them progressively as they grow, allowing a single planting to produce for ten to eleven months. Plant density, leaf removal and truss pruning are the levers growers use to balance vegetative growth against fruit load through the season.

Yield varies with light, cultivar and facility specification more than with grower skill alone, which is why comparing a facility against regional benchmarks matters more than against a global figure.

• Unheated, seasonal production: 25 – 40 kg/m²
• Heated glass, year-round: 55 – 70 kg/m²
• Heated glass with supplemental lighting: 75 – 100 kg/m²
• First production cycle typically reaches 80 – 90% of mature yield

In heated tomato production energy commonly accounts for 30 to 45 percent of operating cost, which makes it the factor most likely to determine whether the facility is profitable. The screen and buffering package is therefore not an optional upgrade — it is the specification that governs cost per kilogram for the life of the asset.

• Dual energy screens: 30 – 50% heating reduction against no screens
• Heat buffer tanks shift heating load away from peak tariff hours
• Combined heat and power supplies heat, electricity and CO₂ together
• Double glazing suits cold climates despite the light penalty

Tomato labour is moderate but continuous, spread across harvesting, leaf removal, truss work and lowering. Because the workload is steady rather than sharply peaked, it is easier to staff with a stable core team than berry crops are — which is often a decisive advantage where seasonal labour is scarce.

The recurring causes of disappointing tomato facilities are consistent, and almost all of them are decided before the first plant arrives.

• Gutter height too low, permanently limiting climate buffering
• Screens omitted to reduce capital cost
• No CO₂ dosing, capping achievable yield
• Humidity control underestimated, driving disease pressure
• No experienced grower contracted for the first cycle