Pest and disease issues can wreak havoc on greenhouse production, even as plants are being prepared for shipment. Pests and diseases don’t take time off, and managing these issues is essential to a productive year, especially during the busy spring season. Here are seven tips for getting ahead of and solving pest and disease issues:
Research insecticides, bugs and other pest-related topics in order to make the most informed decisions.

1. Know when your plants are most vulnerable.

Plants are most susceptible to bacterial diseases when water is on the foliage. After the propagation stage, the disease pressure may not be as strong as it would be at the beginning of the process. But plants can still be vulnerable just before they are due to be shipped out to stores. Additionally, use the internet as a resource to understand different diseases. A simple search for whatever color spot you see can yield useful track sheets, fact cards and tips, although you should verify the diagnosis with a professional. Place the information in an area where all employees can easily reference it. Be sure to take photos of any plant you think may be infected. For more on protecting your plants from bacterial diseases, read “The case of spotty bacteria” at

2. Prioritize sanitation.

Sanitation is any greenhouse’s first line of defense against disease. Weeding inside and outside of the greenhouse, removing plant debris and reducing algae are three ways to properly sanitize a greenhouse. It’s also important to monitor it regularly. Making an action plan that includes specific tasks for specific employees can be helpful, as well. Get more sanitation tips and tricks at

3. Know which biocontrol agents are most useful for your operation.

Biological controls are designed to help growers. Picking one can be difficult, as each one affects different pests in different ways. Consult this chart created by Dr. Raymond Cloyd, professor and extension specialist at Kansas State University, to help match the right biological control with the correct pests, at

4. Do your homework.

Insecticides are an important part of most greenhouse pest management programs. To pick the right insecticide, it’s important to understand your intent, common issues greenhouses face and your timeline for having plants ready. Expand your insecticide knowledge by reading “Don’t let pests prevail”at

5. Learn from other growers.

Thorsen’s Greenhouse, located in Delaware, Ohio, completed its last growing season using only biological pest controls, and didn’t encounter a single disease issue during their holiday plant production. While growing in a 50,000-square-foot facility, Thorsen’s utilized a three-part pest and disease control regimen that started during cutting and was completed during finishing. Assistant grower Marilyn Norman had the idea to implement the program after attending a workshop at Four Star Greenhouses in Michigan in 2015.

Learn from Norman’s efforts and attend any relevant workshops in your area. Call growers you’ve met at trade shows and see what they are doing to combat pest and disease. Consider reaching out to extension professionals at nearby universities. Learn more about Thorsen’s effort by reading “2017 Greenhouse Greats: Biological Control” at

6. Create a consistent environment.

Not only can creating a consistent environment keep costs down, but it can also help keep your greenhouse free of pests and disease. Clean fans, seal in heat and keep an eye on temperature by installing updated thermostats and electronic controls to maintain ideal growing conditions. This process can take time, so plan and delegate maintenance responsibilities to employees as necessary. Also, consider making a checklist so no task is left undone. Read more on creating a healthy growing environment at

7. Put an emphasis on scouting.

Go row by row and check every plant to make sure it’s healthy. Check the undersides of leaves to find any insects and mites hiding on the bottom. Hone your monitoring and scouting strategies with Cloyd’s tips at

Chris is assistant editor of Greenhouse Management magazine.