Winter puts greater stress on every part of a commercial greenhouse: heating systems run longer, ventilation strategies change, snow and ice add structural load, and small gaps or equipment problems that seemed minor in warmer weather can become costly. An inspection before severe weather gives the team time to correct problems before they affect production.
Start with the structure and envelope
Walk the greenhouse inside and outside and check framing connections, doors, vents, glazing, poly coverings, seals and other exterior components for wear. Damaged weather stripping, aging seals, loose panels and gaps around doors or vents can increase heat loss and complicate environmental control. Snow and wind requirements vary by location and greenhouse design, so operators should understand how climate-adaptive design affects structural performance in their area and maintain components according to the intended design and local requirements. If structural condition or winter loading is a concern, involve the greenhouse manufacturer or a qualified professional rather than waiting for the first major storm.
For polyethylene-covered greenhouses, inspect the covering for punctures, tears, looseness or deterioration. Inflated double-poly systems should also be checked to confirm the inflation system works properly.
Service heating and controls before cold snaps
A heating problem in July may be an inconvenience. One during a January cold snap can become an operational emergency. Inspect the entire heating system before temperatures drop and complete manufacturer-recommended service. Boilers, unit heaters, radiant systems, pumps, fans, thermostats, sensors and distribution equipment should all operate as intended.
- Inspect heating equipment for visible wear or operating issues.
- Check thermostats and environmental sensors for proper operation.
- Test circulation and horizontal airflow fans.
- Confirm vents and louvers open and close correctly.
- Inspect control systems, alarms and backup systems.
- Check fuel supplies or fuel delivery arrangements where applicable.
- Review generator or emergency power procedures.
Balance ventilation, humidity and heat loss
Winter greenhouse management is rarely about heating alone because humidity, airflow, ventilation and temperature interact. Reducing ventilation too aggressively to conserve heat can create humidity problems, condensation and uneven growing conditions. The aim is to maintain the conditions the crop needs while operating the greenhouse as efficiently as practical. Heating is often one of the largest winter operating demands, so small efficiency problems are worth finding before the coldest weather.
Inspect the building envelope for escaping conditioned air: doors that do not close properly, worn seals, gaps around penetrations, damaged glazing and poorly maintained vents can all make heating systems work harder. Where installed, inspect retractable energy curtains or thermal screens, including material, drive system, cables, motors, sensors and controls, before the system is needed every night. Some growers add inflated polyethylene over polycarbonate or glass sidewalls and gable ends in fall for extra insulation where appropriate for the design and operation; this can reduce heat loss without permanently changing the glazing.
Keep equipment and storage areas from interfering with airflow or heating distribution. A heating system may operate correctly yet produce inconsistent temperatures if benches, stored materials, equipment or temporary barriers disrupt air movement.
Review operating assumptions and storm roles
Review whether the greenhouse is still operated as originally designed. Production layouts, crops and benches change, structures are expanded, and environmental equipment that worked for the original operation may need adjustment as the business evolves.
A winter plan should go beyond routine maintenance. The team should know what happens when severe weather arrives and who is responsible for monitoring snow accumulation, heating equipment, alarms, backup power, vents and other critical systems during storms or extreme cold. Keep gutters, drainage paths and areas around the greenhouse clear where practical so melting snow and ice can drain. Inspect doors and emergency exits to make sure winter weather will not prevent access.
Manage snow without undermining insulation
Growers in snow-prone climates may consider dedicated gutter snow-melt piping installed beneath the gutters. The system can operate as its own heating zone and be activated only when snow or ice is present on the roof or in the gutters. Supplying heat directly where melting is needed may allow energy curtains or blackout systems to stay closed instead of being opened simply to let greenhouse heat reach the roof and gutters. This helps maintain the greenhouse's insulating layer while managing snow and ice accumulation.
Snow removal should follow the recommendations for the specific greenhouse design. Improper removal can damage coverings or structural components, and unnecessary personnel activity on or around a snow-loaded greenhouse can create safety risks. Operators should understand the snow and wind conditions the greenhouse was designed to handle and have a response plan for unusual weather.