Healthy Plants = Happy Customers

Wendy Komancheck

If you’re a garden retailer who also grows plants to sell, you worry about pests and pathogens attacking your stock. You probably also know how vital greenhouse sanitation is and the lack of sanitation can ruin the crops you’re hoping to sell.

Pictured right: You’ll need to thoroughly clean algae in a greenhouse, including in tight spaces.

To get some tips and tricks regarding greenhouse sanitation for garden retailers, I interviewed Eric Smith from BioSafe Systems and Denise Schreiber, author, former greenhouse manager and horticulturist with Allegheny County Parks in Pittsburgh, Pennsylvania.

Since garden centers and greenhouses are humid, especially in the summer, algae is always a potential danger—not only for the plants, but also as a slip-and-fall concern.

Sanitizing your greenhouses and garden centers protects your plants by removing algae, pests and diseases.

“Algae is a food source for shore fly and fungus gnat larvae, and can be a host for other insects that carry Pythium and things like that,” Eric said. “Pythium can ride along on those organisms.”

He went on to say that as the gnats grow into adulthood, they’ll infest a plant on the benches for sale.

Eric also said with regard to slip-and-falls, “I think garden retail or a garden center is a very public-facing facility where you got people of all ages walking through the facility, and the last thing you want is some sort of a safety hazard. Algae presents that as a slip-and-fall reality, so from a management perspective, you would want to be very proactive in combating algae in a retail setting.”

Pictured below: Getting rid of algae after the growing season keeps your greenhouses sanitized.

Greenhouse sanitation is part of the overall IPM (Integrated Pest Management) puzzle, regardless of its facility, such as an independent garden center or a commercial greenhouse operation, Eric noted. He believes sanitation, in general, makes a big difference, including the disinfectants used on wood, concrete, gravel, benches and floors.

Part of keeping that clean environment means removing debris. For example, your greenhouses shouldn’t have the following lying around:
•    Cuttings
•    Dead plants
•    Weeds, including those that are growing inside and outside the greenhouse
•    Plant material
•    Spilled media

“Maintaining a clean environment helps in a very big way to prevent pests and diseases because a lot of times, say in the case of simple weeds, there are insect pests like thrips, whiteflies, aphids and such,” Eric explained. Those pests can be harbored in weeds, affecting a new patch of poinsettias, bedding plants and perennials.
 

If you’re a seasonal operation, after the end-of-season sale, it’s time to clean up your greenhouses.

Denise commented on how dirty greenhouses get after the spring season. She said, “At the end of the growing season, we would first remove all of the weeds and we would wash the shade cloth with a little laundry soap in a bucket and run it through a siphon on an old hose.

“We used a straight tip on the hose since we weren’t 18-ft. tall. After that, we would wash the block walls with a stiff-long brush with Green Shield to remove algae that would accumulate. We would do a quick rinse to remove the algae and sweep it out of the greenhouse.”

She described putting in concrete walks and replacing older wooden benches with poly benches with legs. These items may cost a little more, but they can reduce the chances of pests and pathogens in the greenhouse.
 

Eric recommended that retail management train their staff to scout the selling floor for diseases and insects on plants. He said it can be a daily walk-through for certain crops under seasonal pressure.

“You want to make sure that those are being scouted semi-often, a couple of times a month, to make sure that the products they’re selling [in the garden center] are pest- and disease-free,” he noted. “But the retail center could have some of their staff trained on scouting, and there are online courses from UF [University of Florida] and several other institutions.”

He also mentioned that staff can use their phones for scouting by placing a little pocket scope that clips onto the phone’s camera as a magnifying glass. This enables the staff to scout like commercial greenhouses. GP

Wendy Komancheck owns The Landscape Writer and is a proud Garden Communicators International member. She writes for green industry trade magazines and content for lawn care, landscape and gardening services. You can email her at wendy@landscapewriter.com.