Commercial greenhouses face added pressure in winter, when heating systems run longer, ventilation changes, and snow, ice, and wind place greater loads on structures. A seasonal inspection completed before severe weather gives growers time to correct problems that could otherwise interrupt production or raise energy costs.
Start with the structure
Growers should walk the greenhouse inside and outside, checking framing connections, doors, vents, glazing, polyethylene coverings, seals, and exterior components for damage or looseness. Air and moisture entry points deserve attention because worn weather stripping, aging seals, loose panels, and gaps around doors or vents can increase heat loss and complicate environmental control.
Polyethylene-covered houses should be checked for punctures, tears, looseness, and deterioration. Inflated double-poly systems need confirmation that inflation is working. Snow and wind requirements vary by location and design, so structural maintenance should follow the building's intended design and local requirements. If condition or winter loading is uncertain, the greenhouse manufacturer or a qualified professional should be involved before a major storm.
Service heating before demand peaks
A heating failure in January can become an operational emergency. Before temperatures fall, the entire heating system should be inspected and manufacturer-recommended service completed. Boilers, unit heaters, radiant systems, pumps, fans, thermostats, sensors, and distribution equipment should operate as intended.
The checklist should cover visible wear or operating issues; thermostat and environmental sensor operation; circulation and horizontal airflow fans; vent and louver movement; control systems, alarms, and backups; fuel supplies or delivery arrangements where applicable; and generator or emergency power procedures.
Coordinate controls, airflow, and energy use
Winter management is not only a heating task. Humidity, airflow, ventilation, and temperature interact, and cutting ventilation too sharply to save heat can lead to humidity, condensation, and uneven growing conditions. The aim is to meet crop requirements while operating the greenhouse as efficiently as practical.
Heating is often a major winter operating demand, so the building envelope should be checked for escaping conditioned air. Doors that do not close properly, worn seals, gaps around penetrations, damaged glazing, and poorly maintained vents can all increase heating load. Retractable energy curtains or thermal screens should be inspected, including material, drive system, cables, motors, sensors, and controls, before nightly use.
Some growers add inflated polyethylene over polycarbonate or glass sidewalls and gable ends in fall for extra insulation. Where suitable for the design and operation, this seasonal layer can reduce heat loss without permanently changing the glazing. Equipment and storage should also be arranged so they do not interfere with airflow or heat distribution; even a working heating system can produce inconsistent temperatures if benches, materials, equipment, or temporary barriers disrupt air movement.
Review snow, drainage, and emergency roles
A winter plan should go beyond routine maintenance. The team should know who monitors snow accumulation, heating equipment, alarms, backup power, vents, and other critical systems during storms or extreme cold. Gutters, drainage paths, and areas around the greenhouse should be kept clear where practical so melting snow and ice can drain, and doors and emergency exits should remain accessible.
In snow-prone climates, dedicated gutter snow-melt piping installed beneath gutters can operate as a separate heating zone and be activated when snow or ice is present on the roof or in the gutters. By supplying heat where melting is needed, this approach may allow energy curtains or blackout systems to remain closed instead of opening them to let greenhouse heat reach the roof and gutters, helping preserve the insulating layer while managing accumulation.
Snow removal should follow 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 structure was designed for and have a response plan for unusual weather.