January 2012 Newsletter (vol.3)   >>   Cleaning House

Clean Greenhouse


Patrick Steppuhn, Hummert’s greenhouse guru, has a mantra about how to have a pest-free greenhouse, “Start Clean. Keep It Clean.” Cleanliness is a key ingredient for a healthy greenhouse. Your goal should be a spotless greenhouse where insects and fungi have a hard time surviving. Now is a perfect time to clean house.

First, remove dirt and organic matter from your greenhouse by starting at the top and working your way down. Once you have removed the dirt and organic matter you will then disinfect all the surfaces.


Figure 1. Underside of greenhouse bench.


Figure 2. Dirt, debris, and algae on floor with plant growing in trench drain.


Start by cleaning your polycarbonate, glass, benches and floors with detergent or mild soap. Remove as much dirt and organic matter from glass or polycarbonate by using our greenhouse pole washer. Clean the top and underneath the benches Figure 1. Use a long handled scrub brush to remove dirt, algae, & debris from floor Figure 2. Remove grates and clean trench drains and catch basins. An inexpensive sweeper nozzle is a great tool to help you push debris in your trench drain, Figure 3. Remove the grate on the catch basin and remove solid debris, Figure 4.


Figure 3. Trench drain full of debris.


Figure 4. Debris in a catch basin


Next, clean your evaporative cooling system. Disconnect the bleed off if your system is equipped with one. Remove all debris from pads and reservoir, Figure 5. Rinse the pan area. Fill the reservoir with clean water and add J.R.’s Once-Through Cleaner . Disengage blower and circulate for 6 to 12 hours. Repeat if build up is excessive. At end of cleaning attach hose to drain and flush reservoir. Engage blower and refill reservoir with fresh clean water and J.R. Evaporative Cooler Treatment.


Figure 5. Dirty evaporative cooling system reservoir.


Clean your doorways and entrance pad. Inspect, repair and replace boot scrapers at entrance. Consider using a shoe bath with disinfectant at entrance of greenhouse to prevent dirty boots from bringing in insects, fungi and bacteria. End by cleaning your sink. Keep it sparkling clean every day.


Now you are ready to disinfect. We recommend hydrogen dioxide or quaternary ammonium chloride salts for disinfecting greenhouses. Hydrogen dioxide (hydrogen peroxide) is an oxidizer that kills fungi, bacteria, and algae on contact by denaturing proteins and lipids. Zerotol , Sanidate,GreenClean RTX , GreenCleanPRO, Terraclean , and Terracyte Pro are hydrogen dioxide-based products that are labeled for different uses and types of surfaces. Quaternary ammonium chloride salts are either ADBAC, (GreenShield & Microbloc ), or benzylkonium chloride,(Physan 20 ). These general disinfectants kill viruses, bacteria, fungi, mildew, and algae while also deodorizing. Physan 20 can also be used to treat seeds and plants.


The number one carrier of diseases is actually the water you grow your plants with. To keep your greenhouse clean, consider treating your system with the water disinfectant chlorine dioxide, Ultra-Shield . Chlorine dioxide will kill algae, bacteria, and fungi in your irrigation lines. You can choose to dedicate an injector to continuously maintain your irrigation system at low rates. Or you can shock treat your irrigation system to remove pest build up in lines at higher rates.


Finally, here are some other good rules for your greenhouse. No smoking. If you do smoke, disinfect your hands before entering the greenhouse to prevent spreading tobacco mosaic virus. Clean your boots before entering or change into a clean pair of greenhouse shoes or boots. Keep hose ends off the floor. Remove pet plants, unnecessary plants, infested plants, and weeds under benches. Control ants as they can harbor and protect aphids, mealy bugs and scales. Disinfect the handling area.


Keep your greenhouse clean by making cleaning and maintenance a routine part of your greenhouse operations. A clean greenhouse is a key ingredient for healthy plants. Start clean and keep it clean.


Zulovich, Joseph. “Maintenance of Evaporative Cooling Systems.” University of Missouri Extension. July 2009. <http://agebb.missouri.edu/swine/pdf/EvapCoolingMaintenance-7-09.pdf>.


D. E. Buffington, et al. “Maintenance Guide for Greenhouse Ventilation, Evaporative Cooling Heating Systems.”  September 2008. <http://edis.ifas.ufl.edu/pdffiles/AE/AE02400.pdf>.


“How to Maximize Pad Life...” Port-A-Cool, LLC. September 2010. <http://www.kuulpads.com/downloads/PADMAINTENANCE.pdf>.


“APPROVED Products and Chemicals for use with KÜÜL® pads:” Port-A-Cool, LLC. September 2010. <http://www.kuulpads.com/downloads/KUULAPPROVEDCHEM.pdf>.