Jack Frost has already drawn up his list of greenhouses to visit. Will you be ready? Here's the routine we follow at our house each fall:

1. Clean The Greenhouse

Take all plants out of the greenhouse and thoroughly clean the frame, glazing and benches.
Physan 20 is an effective disinfectant.

Make glass sparkle brightly again with Glass Cleaner. For stubborn algae spots, I spray with Physan 20 or household bleach and let them soak before rinsing. For tree pitch and adhesive residue, use a good Citrus Cleaner .

Fiberglass and TwinWall or TripleWall polycarbonate should be rinsed and then washed with a mild liquid dishwashing soap and lukewarm water. Use a soft cloth or sponge. For polycarbonate, rub only in the same direction as the channels to avoid scratches that show.

Wood frameworks will benefit from another application of copper or zinc preservative or latex paint. Metal frames, door hinges and vents should be oiled with a good Lubricant .

2. Heat Conservation/Insulation

If you have wanted to upgrade your greenhouse, summer is the time to replace poly or single glass with insulated TwinWall.

Replace any broken glass or aging poly cover. Caulk as necessary, especially around the foundation. Apply foam tapes to doors and vents to make an airtight seal.

If you have single layer glass and plan to heat your greenhouse, Bubble Insulation can provide significant heat savings. Simply apply to the inside of the walls and roof. North walls and solid walls should be lined with a aluminized reflective barrier for maximum insulation and light reflection. If you frequently have freezing weather, line all but the south wall with a aluminized reflective barrier. For sub-zero climates, place a aluminized reflective barrier across the south glazing at night.

If you already have insulated polycarbonate glazing, use a Greenhouse Liner to reflect light and radiant heat.

3. Check Your Heater

Test run your heater and replace any component that does not operate perfectly. Clean the fan blades, oil the motor and protect the housing and electrical connections with Rust Protection Strips.

Check the accuracy of the heater thermostat... Monitor air temperature with a min./max. thermometer. Set the heater thermostat 10°F above the present temperature. When the heater shuts off, reset the min./max. thermometer. Let the system run for 30 minutes with several on/off cycles. Check the min./max. thermometer. Variation should be 2°F to 4°F. More than 6°F variation should be investigated and corrected.

4. Winter Storm Emergencies

Keep a backup heater ready for immediate use. Also have on hand a winter shield, extra poly and poly repair tape. Make a checklist of what to do if severe weather strikes or the greenhouse heater fails.

Power Failure: A battery-operated Temperature Alarm is essential if the heat goes off in the middle of the night. Portable propane and kerosene heaters are popular emergency heaters, but both require some ventilation. If you do not have a backup heater, you can provide temporary heat by draining the household water heater and placing buckets of hot water in the greenhouse. Cover the plants with newspapers.

If Freezing Is Unavoidable: BE SURE TO DRAIN ALL WATER LINES! Spray plants with water. A coating of ice (32°F) will offer some protection from colder temperatures for hardier plants.