PO Greenhouse Film for Winter: More Light When Days Are Short

Winter Is a Light Problem, Not Just a Temperature Problem

Growers talk about winter as a cold problem, but for a covered crop the binding constraint is usually light. Day length shrinks, the sun angle drops, and the same greenhouse that was bright in October turns dim in December. At low light levels, the difference between a cover that transmits 92%+ and an ordinary film is no longer a rounding error — it is the margin between crop growth and crop holding.

This is why PO film’s transmission is a winter feature, not a brochure number. The multi-layer optical structure keeps transmission high as the film ages, so the light you design for in autumn is still there in February.

What −40~+60 °C Actually Covers

The working range spans both extremes your tunnel will see: deep-winter nights on one end, closed-house summer peaks on the other. One film covers the whole year — you are not swapping covers seasonally, and the material is rated for the cold nights that crack lesser films. Note what this claim is: a rated working range for the film, verified by testing — not a promise about your heater.

Five Winters Without Replacement

A 3–5 year service life changes the winter arithmetic. Over the life of one PO cover, a seasonal film would have been bought, fitted and removed several times — each cycle costing film, labour and days of downtime in the worst weather of the year. Spreading one installation across five winters turns the covering into a scheduled capital item instead of an annual emergency.

5-Layer Co-extrusion in Plain Terms

PO film is built in layers, each with a job: outer layers carry the UV stabiliser package that protects against year-round radiation, middle layers carry strength, and the inner layer carries the anti-drip effect that keeps condensation running to the gutter instead of dripping onto the crop. Five layers extruded together are why the film can hold transmission, strength and anti-drip at the same time — and hold them for years, not months.

When to Install Before Winter

The best installation window is before the first sustained cold snap: fitting film in mild weather is faster, safer and lets you tension it properly. If your current cover is already at end of life, replacing it in late autumn is almost always cheaper than gambling it through a winter. Our seasonal guide to replacing greenhouse film before winter walks through the timing and the inspection checklist.

Frequently Asked Questions

Related reading: Greenhouse Film Replacement Before Winter · PO Film vs PE Film · PO Greenhouse Film · Request a Quote