Red Oakleaf Lettuce — DutchGreenhouses

Lobed leaf and red pigment, usually sold as part of a set

Red oakleaf combines the lobed leaf shape of the oakleaf types with red pigmentation. It most often reaches the consumer as one component of a multi-type pack rather than as a wholehead on its own, which changes what the grower is optimising for.

What the crop needs

The crop is short-cycle and hydroponic, with the open head structure of the oakleaf types and the light-driven colour development of the red types. Because it is frequently sold in a set, head size consistency with the other components matters as much as the absolute size.

What the greenhouse has to do

Red oakleaf is usually sold as part of a set rather than on its own, and that changes what the house is being asked for. A trio or a mixed pack needs its components ready together, so planting schedule and compartment planning are built around the pack date, not around each type’s own fastest cycle.

Colour and shape are both the product, and both are fragile. Pigment follows light, so the light plan and the screening strategy are specified for colour as well as growth; the lobed leaf damages easily, so the harvest route is kept short. Even transmission across the floor is what keeps a batch matching itself inside the pack.

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.

Butterhead lettuce

Soft, loosely wrapped leaves, and the type least tolerant of handling.

Greenleaf / Batavia lettuce

A firmer, more robust head than butterhead, and it travels better.

Romaine lettuce

The upright head, and the tipburn risk that comes with it.

Hydroponics

Substrate growing with drip supply and drain recirculation.

Climate

Heating, cooling, humidity control and carbon dioxide dosing.

Questions

Red oakleaf 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

Red oakleaf 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

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.

From the knowledge base