Winter conditions place commercial greenhouses under greater pressure, with heating systems running longer, ventilation strategies shifting, and snow and ice adding structural loads. Minor gaps or equipment problems that seemed manageable in warmer weather can become costly during cold snaps, so growers are advised to inspect and prepare the structure and its environmental systems before severe weather arrives.
Winterizing is not only about warmth. It is about reducing downtime, protecting crop quality, controlling energy use and ensuring the structure and environmental systems can perform when outside conditions become less forgiving. A thorough inspection gives teams time to address problems before they affect production.
Structural inspection
The structure should be inspected first. Walk the greenhouse inside and out and look for damaged or loose components, including framing connections, doors, vents, glazing systems, poly coverings, seals and exterior parts. Snow and wind requirements vary by location and greenhouse design, so operators should understand how climate-adaptive design affects structural performance in their region.
Pay attention to places where air or moisture can enter. Damaged weather stripping, aging seals, loose panels and gaps around doors or vents can increase heat loss and complicate environmental control. For polyethylene-covered houses, check for punctures, tears, looseness or deterioration, and confirm that inflated double-poly systems are inflating properly. If structural condition or winter loading is a concern, involve the manufacturer or a qualified professional rather than waiting for a major storm.
Heating and controls
A heating failure in July may be inconvenient; one during a January cold snap can become an operational emergency. Before temperatures fall, inspect the entire heating system and complete manufacturer-recommended service. Boilers, unit heaters, radiant systems, pumps, fans, thermostats, sensors and distribution equipment should operate as intended.
The checklist should include inspecting heating equipment for visible wear or operating problems; checking thermostats and environmental sensors; testing circulation and horizontal airflow fans; confirming vents and louvers open and close correctly; inspecting controls, alarms and backup systems; checking fuel supplies or delivery arrangements where applicable; and reviewing generator or emergency power procedures.
Environment and envelope
Environmental controls need particular attention because winter management is rarely about heating alone. 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 crop requirements while operating as efficiently as practical.
The building envelope is another priority. Doors that do not close properly, worn seals, gaps around penetrations, damaged glazing and poorly maintained vents can let conditioned air escape and make heating systems work harder. Where installed, retractable energy curtains or thermal screens should be checked for material condition, drive systems, 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 measure can reduce heat loss without permanently changing the glazing. Equipment and storage areas should also be kept from interfering with airflow or heat distribution; benches, stored materials, equipment or temporary barriers can disrupt air movement and produce inconsistent temperatures even when the heating system is operating correctly.
Storm readiness
A winter plan should extend beyond maintenance. Teams 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.
Growers in snow-prone climates may consider dedicated gutter snow-melt piping beneath gutters. Such a 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. By supplying heat where melting is needed, it may allow energy curtains or blackout systems to remain closed rather than opening them to let greenhouse heat reach the roof and gutters, helping maintain 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 greenhouse was designed to handle and have a response plan for unusual weather.