Winter places heavier demands on every part of a commercial greenhouse: heating plants run longer, ventilation strategies change, snow and ice add structural load, and small gaps or equipment faults that were harmless in warm weather turn costly. The point of a winterization program is not simply keeping the house warm, but limiting downtime, protecting crop quality, controlling energy use and confirming that structures and environmental systems can perform when outside conditions deteriorate.
Inspecting before severe weather arrives leaves the team time to fix problems before they reach production.
Start with the structure
Walk the house inside and out before hard weather: framing connections, doors, vents, glazing, poly coverings, seals and other exterior components all need checking for damage or looseness. Snow and wind requirements vary by location and design, so operators should understand how climate-adaptive design affects structural performance in their region. Watch for paths where air or moisture can enter — worn weather stripping, aging seals, loose panels and gaps around doors or vents raise heat loss and complicate environmental control. Poly coverings need inspection for punctures, tears, looseness or deterioration, and inflated double-poly systems should be confirmed to be inflating properly. If structural condition or winter loading is in doubt, bring in the manufacturer or a qualified professional rather than waiting for the first major storm.
Heating is the emergency risk
A heating failure in July is an inconvenience; during a January cold snap it becomes an operational emergency. Before temperatures drop, inspect the whole system and complete manufacturer-recommended service — boilers, unit heaters, radiant systems, pumps, fans, thermostats, sensors and distribution equipment. The checklist should also cover:
- Checking thermostats and environmental sensors for correct operation
- Testing circulation and horizontal airflow fans
- Confirming vents and louvers open and close fully
- Inspecting controls, alarms and backup systems, and fuel supply or delivery arrangements
- Reviewing generator and emergency power procedures
Balance ventilation against humidity
Winter management is rarely about heat alone, because humidity, airflow, ventilation and temperature interact. Cutting ventilation aggressively to conserve heat invites humidity buildup, condensation and uneven growing conditions. The aim is to hold the conditions the crop requires while running the house as efficiently as practical.
Find the heat leaks
Heating is typically among the largest winter operating demands, which makes small efficiency faults worth finding before the coldest weather. Doors that do not close, worn seals, gaps around penetrations, damaged glazing and poorly maintained vents all force the system to work harder. Where retractable energy curtains or thermal screens are installed, check fabric, drive system, cables, motors, sensors and controls before the system is needed nightly. Some growers add inflated polyethylene over polycarbonate or glass sidewalls and gable ends in fall for an extra insulating layer; where the design and operation suit it, the seasonal measure reduces heat loss without permanently altering the glazing.
Benches, stored materials, equipment and temporary barriers can disrupt air movement, producing uneven temperatures even when heating equipment is running correctly. Winterizing is also a moment to ask whether the house is still operated the way it was designed: production layouts, crops and benches change and structures get expanded, so environmental equipment may need readjustment.
Plan for storms and snow
A winter plan should go beyond maintenance. Assign who monitors snow accumulation, heating equipment, alarms, backup power, vents and other critical systems during storms or extreme cold. Keep gutters, drainage paths and the ground around the house clear so melting snow and ice drain, and confirm doors and emergency exits stay accessible. Growers in snow-prone climates may consider dedicated gutter snow-melt piping beneath the gutters, operated as its own heating zone and switched on only when snow or ice sits on the roof or in the gutters; heating where melting is needed can let energy curtains or blackout screens stay closed rather than being opened to let house heat reach the roof, preserving the insulating layer while managing accumulation.
Snow removal should follow the recommendations for the specific design; improper removal damages coverings and structure, while unnecessary traffic on a loaded roof creates safety risk. Operators should know the snow and wind conditions their house was designed for and hold a response plan for unusual weather.