The red Lolla, where curl and colour are both the product

Lollo Rosso is the red Lolla type, with the same tightly curled margin as Bionda and red pigmentation through the leaf tips. It is a mixed-pack and garnish staple, bought for the colour and texture it adds rather than for mass.

What the crop needs

The crop is short-cycle and hydroponic. It carries the curled-leaf air movement requirement of the Lolla types together with the light-driven colour development of the red types, so spacing and shading affect both the health of the head and its saleable appearance.

What the greenhouse has to do

Curl and colour are both the product, and each has its own driver. Form follows a steady, unhurried climate that keeps the plant compact; pigment follows light. The two have to be held together, which is why the light plan and the screening strategy are specified against colour development and not only against growth rate.

The rest is short-cycle lettuce economics: density, the recirculating water system and the harvest route decide how many heads reach grade in a year. An appearance crop has little tolerance for an uneven floor, because a difference a buyer can see is a difference that costs the grade even when the weight is right.

DutchGreenhouses® designs the structure, climate, screening and irrigation around the lettuce type, its system and the local climate, so cycles turn at the head quality the market grades on. Get in touch to plan a lettuce greenhouse.

Questions

Lollo Rosso lettuce, asked and answered

Is head weight or head count the right target?

Lettuce is sold by the head, so the count reaching grade in a year decides revenue. A heavier head grown more slowly can earn less than a lighter head on a shorter cycle.

Does the cultivar matter more than the type?

For head mass, density tolerance and tipburn risk, yes. Those are cultivar properties, which is why a lettuce project is planned around a named cultivar rather than around the type alone.

What causes tipburn?

Calcium not reaching the fastest-growing leaf margins, driven by transpiration and root pressure rather than by supply. Climate control addresses it; adding calcium to the solution generally does not.

Crop data

Lollo Rosso lettuce — reference values

Reference values from the DutchGreenhouses crop model, each traced to its Dutch source below. Ranges describe published practice across systems and seasons; a project setpoint is calculated for the actual greenhouse, crop and climate.

Day climateMedium confidence1

Air temperature
21–22.7 °C
Relative humidity
60–80 %
Daily light integral
11.5–13.2 mol/m²/d
CO₂ concentration
1000–1100 ppm

Irrigation and root zoneMedium confidence1

Supply EC
1.6–1.8 mS/cm
Supply pH
5.5–6 pH

Where these come from

  1. WUR, 2018, WPR-813 — Lettuce on water under glass with LED. WUR research report · High confidence · E067Primary direct evidence, but one research greenhouse and four named lettuce types/cultivars. Numeric values are operating observations, not universal optima.

These are reference values, not a specification. DutchGreenhouses does not publish project setpoints; those are calculated per greenhouse, crop and location.

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