Tomatoes.

The benchmark crop of Dutch greenhouse horticulture

Tomatoes are the crop against which high-tech greenhouse growing is measured. They thrive in warm, well-ventilated conditions with a consistent balance of light and dark: at least six to eight hours of good light for photosynthesis, and a dark period that supports respiration and healthy fruit development. Grown under glass on hydroponic substrate, a tomato crop typically stays in the greenhouse for 20 to 30 weeks, allowing multiple cycles per year depending on variety and local climate — and modern construction makes it possible to hold those conditions steady almost anywhere.

Climate and light are the foundation. Tomatoes flourish at a 24-hour average temperature of roughly 21–27°C — in a Dutch-style setup often steered to about 28°C by day and 18°C at night — with relative humidity held around 70–75% to encourage transpiration while preventing fungal disease. Enriching CO₂ to around 800 ppm lifts photosynthesis, and LED or hybrid LED/HPS lighting extends production through the darker months. A tomato greenhouse is usually specified with diffuse or shade screens in the top layer and energy screens below, on an 8-metre truss with hanging-gutter cultivation.

Tomatoes are a labour-intensive, year-round crop. Segmented planting keeps harvesting continuous and the workforce steadily occupied across seeding, transplanting, pruning, harvesting and integrated pest management — typically around ten people per hectare plus management and support staff. Because the tasks never really stop, a well-organised team and clear cultivation protocols are as important to the result as the hardware.

Commercially, tomatoes are a resilient proposition. Demand for fresh, locally grown fruit is stable year-round across countless cuisines and both local and export markets, insulating growers from the seasonality that affects other crops. Yields vary widely by cultivar — from around 28 kg/m² for cherry types up to 90 kg/m² for beef tomatoes — though once labour costs are factored in the bottom line often converges. Revenue can reach roughly €60 per square metre per year or more depending on the market, and while energy is a real cost, efficient climate technology and renewable sources can offset much of it. A commercially viable operation usually starts around 40,000 m² and is comfortably managed up to about 80,000 m². To model the return on investment for a tomato project in your market, get in touch with our experts.