Winter is Coming Make Sure Your Greenhouse Is Ready

Steve Froehlich, Horticultural Engineer and Crop Consultant

As the splash of tree color fades, leaves fall, and nature prepares for winter sleep, it is once again time to give consideration to the health of your greenhouse.   With diminishing day length and declining daily temperatures checking greenhouse equipment can save you money and avoid potential losses.  The following are considerations as the winter season approaches.


Check your heaters carefully.  Heaters not operating properly can be deadly to both people and plants!

  1. Inspect heat exchangers for cracks, holes and rust.  Vacuum dust, dirt, and cob webs.  Replace heater if damage is found.  Never try to repair damaged heat exchangers.
  2. Inspect exhaust flue for rust, damage and insect / bird nests.  Make sure proper weather cap is installed on vent stacks.  Replace, repair and clean as necessary.
  3. Inspect heater burner for dirt, soot, cracks, holes, and rust.  Clean or replace as necessary.
  4. Inspect burner flame for uniformity, color and pattern.  Discrepancies from normal should be look at by a qualified repair technician.
  5. Inspect drain line on condensing heaters for plugging and blockage.  Repair or replace as necessary.

Check your greenhouse controller.

  1. Inspect aspirator fan, housing and filter for proper operation, dirt, insect nests and debris.  Replace and clean as necessary.

  2. Calibrate temperature, humidity, and CO2 sensors against lab grade certified instruments.  Adjust controller and or replace sensors as necessary.
  3. Operate controller making sure all set points are appropriate for the winter season.  Check controller for proper equipment cycling and vent door staging.  Make changes as necessary.

Winterize your greenhouse.

  1. Inspect vent door, power tube fan shutter, and exhaust fan shutters for proper closure.  Worn vent door racks, pinion gears, bent vent door frame, and damaged shutters will waste heat and cause difficulties in maintaining environment uniformity.  Repair and or replace as necessary.

  2. Inspect all door openings into the greenhouse and head house for proper weather-stripping.  Repair and or replace as necessary.
  3. Drain your evaporative cool system sump, water supply and distribution lines, and pump.  This also is a good time to clean and disinfect the system.
  4. Remove shade cloth and shade paint.  
  5. Clean greenhouse cover with a mild soap solution injected through a pressure washer or a garden hose.  A 1% reduction in light entering the greenhouse will lead to a 1% reduction in potential yield.
  6. Check operation of the cover inflation blower.  Make sure you are using outside air for inflation.  Inflation should be approximately 8 to 10 inches at cover center.  Clean blower of dust, dirt and insect debris.  Check for holes in the cover.  Repair or replace as necessary.
  7. Install and check operation of gutter ice and snow melting system if needed to control ice build-up in the gutters.

Happy winter!

Steve Froehlich

Greenhouse greenhouses