Scouting is a Key Component of IPM
Integrated Pest Management (IPM) is a collection of approaches and solutions to avoid, prevent, and manage pests, such as insects, diseases, or weeds. More information on IPM can be found in this publication: Integrated Pest Management for Home Gardens and Landscapes.
The foundation of IPM is scouting, or monitoring plants often, carefully, and systematically with the goal of spotting problems early. Monitoring for pests and diseases is the first and most critical step in preventing damage. Scouting should begin as soon as plants begin to grow or when pests become active. It should continue until plants are dormant or the risk of the pest has passed.
No pest—insect, disease, or weed—is the same. They can be harmful in different population sizes, cause a variety of symptoms on plants, and impact the health of the plant differently. The information gathered from scouting gardens and landscapes can help you decide whether you may need to take additional steps to manage the pest.
How to Scout for Pests in the Garden
Before you Scout
Learn about the plants you are scouting. Learn what type of plant is it and what is normal for the plant. You must know what is normal to notice that something is wrong!
What to Look For
When scouting, it is important to record what you observe, either in writing, pictures, or even video. Keeping a scouting or garden journal is a great way to keep accurate track of your observations. It becomes a record that can be referenced year after year.
Things you should look for when scouting that often indicate a problem:
- Cupped, chlorotic, spotted, or malformed plant parts
- Discolored, damaged, swollen, or sunken leaves and stems
- Pockets of less vigorous or dying plants
- Frequency and number of insects
- Anything out of the ordinary
Tips for Disease Scouting
Scouting for diseases includes monitoring weather (rain, humidity, and temperatures), walking the landscape to inspect foliage and bark on the trunk and limbs for symptoms and frequency (percent of the plant infected) that can indicate changes in pathogen pressures.
Tips for Insect Scouting
Scouting for insects involves properly identifying the insect, knowing the insect’s life cycle (egg, immature or adult), habits and when it causes plant damage. Information from scouting allows you to determine how many pests there are and if you need to take action.
Tools for Scouting
- Camera for taking pictures
- Knife and pruners
- Hand lens for inspecting small insects, mites, insect eggs or feeding damage
- Containers for collecting plant, disease, and insect samples
- Small cooler for transporting and preserving samples
- Beating tray or scouting board to collect and count pest and beneficial insects
- Reference materials for helping identify pests
- Iowa State University Plant and Insect Diagnostic Clinic submission forms have fields that will help you observe the situation, identify patterns, and collect information. The form is free to download.
Scouting Methods
To make the best use of time spent scouting, section the area into manageable portions based on location, size, and plant type, and scout them separately. For best results, scout areas in “X”, “W”, or diamond patterns, and be sure to change patterns every time you scout.
A scouting journal, or garden journal, is extremely helpful when monitoring your plants in your garden. It will help keep accurate dates for different observations made in the garden, from the weather, and more. More information about starting a garden journal can be found in this article: Garden Journaling.
Information to collect in your journal includes:
- Plant, variety, and date planted
- Notes (observation of symptoms or pest appearance, date observed)
- Date of observation
- Took photos: Yes/ No
- Performance/ status (overall look, increasing or declining symptoms, prolific/invasive)
- Pest noticed
- Management tactics employed
- Efficacy of tactics (would I use this tactic again?)
In all cases and if possible, scouting includes reviewing records of previous scouting efforts, management decisions taken and how effective they were.
Next Steps
After scouting and collecting information, the next step is to use that information to identify a problem and start managing that issue.
Several resources are available to help. The best place to start is by searching for the suspected issue on this website or a search engine (i.e. Google). Compare the symptoms you have observed with the symptoms outlined in the resource and if they don't match, look into something else.
Below are some great resources to help identify the problem.
- What's Wrong with My Plant? from the University of Minnesota
- How to Diagnose Problems with Trees in the Landscape
- Herbicide Injury to Garden Plants
- Chemical Injury to Garden Plants
- Managing Weeds in Landscapes, Gardens, and Lawns
- Problem Wildlife
- Plan now, save later: Proactive plant disease management
- Managing Diseases in the Vegetable Garden
- Managing Tomato Diseases, Disorders, and Pests
- Pests and Diseases of Roses
- Diagnosing Houseplant Problems
Anytime you need more help, contact the Plant and Insect Diagnostic Clinic - they can help identify your issue and provide resources to manage it.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on April 10, 2020. The information contained within may not be the most current and accurate depending on when it is accessed.