Greenhouse Integrated Pest Management (IPM)

Please note that pesticide and biocontrol recommendations differ from state to state or between countries. The information presented should be used as a guideline for pest management but should not take the place of the official word of your local county agent or regulatory official.

Pest management is an integral part of any greenhouse operation. Pests can include weeds, nematodes, algae, insects, spiders, diseases, or any unwanted organism that directly or indirectly damages plants. Many greenhouses use Integrated Pest Management (IPM) strategies to manage their pest problems.

IPM can be defined as a systematic approach to managing pests that focuses on long-term prevention or suppression with minimal impact on human health, the environment, and non-target organisms.

An IPM Program consists of:

  1. Monitoring
  2. Identification of Pest Problems
  3. Control Methods
  4. Evaluation

Many growers use IPM in the management of their greenhouses on an ongoing basis. This module will introduce you to Cornell's approach to IPM. Other examples include:

I. Basics of Integrated Pest Management

Threshold tolerance determines the point at which damage and reduced yield will occur if no action is taken. Growers have thresholds that they have learned through experience or from scientific research. The greenhouse grower must determine how much damage can be tolerated before taking action. The decision made must take into account effects on the environment.

1. Monitoring (Scouting) and Assessing

Monitoring, or scouting, refers to the visual assessment of potential or actual pest infestations. IPM requires a thorough and daily assessement of greenhouse plants and their overall appearance. Records of the scouting and assessment (scouting forms) are required and familiarity with the signs and habits of potential greenhouse pests is the key to management and prevention.

2. Identification of Pest Problems

A greenhouse pest is anything that injures the crop or greenhouse structure, competes with the crop for food or water, or spreads disease. There are different types:

1. Insects and spiders

2. Diseases

A very brief summary of diseases is presented here, but for more detailed information on plant pathogens go to Cornell University's On-Line Glossary of Technical Terms in Plant Pathology.

3. Environmental Conditions

A summary of environmental conditions and the symptoms they produce is a useful tool in the greenhouse.



6. Algae

7. Slugs and Snails

3. Control Methods

Once a greenhouse has been properly scouted and assessed, and pests identified, appropriate action should be taken. This can be biological, chemical, cultural, mechanical, or a combination of these strategies.

Biological control includes what the EPA defines as biopesticides, resistant plant varieties, and beneficial organisms. Biological control is safer than conventional chemical control because it allows the greenhouse grower to eliminate or minimize spraying. IPM stesses the use of pest management strategies that have the least impact on the environment.


~Resistant Plant Varieties
~Beneficial Organisms
  • predatory insect
  • fungus
  • bacteria
  • microorganism

To learn how the greenhouse manager can raise beneficial predators for the control of pests, see Hungry, Helpful Insects Thrive on Special Fast-Food. For more information on biological controls and predatory organisms go to Additional Resources. Remember! Biological controls are living creatures and can be adversely affected by chemical use and certain environmental conditions.

The EPA classifies pesticides into two categories:

~General Use
General use pesticides are relatively safe, can be used in home greenhouses and can be purchased from a garden center, a hardware store, supermarket, etc. No special certification or licensing is required.

~Restricted Use
A Restricted Use classification restricts a product, or its uses, to application by a certified pesticide applicator or under the direct supervision of a certified applicator.

There is a great deal more information you need to know to apply restricted pesticides that are not covered in this beginner's course but would be covered in a Pesticide Certification Training course.

4. Evaluation

Evaluation includes keeping records of all aspects of the IPM program the manager followed including techniques used, pests identified, and so on. These records are valuable to future management decisions.

John Kumpf on Integrated Pest Control—

"Pest management in the greenhouse often means getting down on your hands and knees to pull weeds or check for bugs. This approach will reduce herbicide use in the greenhouse."

II. The Label

The most important tool for the safe and efficient use of pesticides is the information contained on the product label. Failure to follow the directions on the pesticide label can harm people and the environment and can result in possible liabilities. Labels are legal documents and contain the following:

III. Worker Protection Standard (WPS)

Worker Protection Standard Guidelines is a set of regulations developed by the EPA for the protection of workers from agricultural pesticides. Both general-use and restricted-use pesticides are covered by the WPS.

IV. Notification & Signage

Workers must be warned prior to application. Dependent upon the pesticide used, this notification can be oral, written or both. The following is a list of important pesticide-related signs to become familiar with:

The law requires that the employer notify workers of any pesticide application in the greenhouse.

Signs must remain visible, legible, and posted throughout the application and restricted-entry interval. They must be removed within 3 days after the end of the application and restricted-entry interval, and before worker entry is permitted.

If the pesticide product labeling has a statement requiring both the posting of treated areas and oral notification to workers, the employer shall also provide oral notification of the application to the worker in a manner that the worker can understand. The warning shall consist of:

  • Description and location of treated area.
  • Restricted-entry interval.
  • Instructions not to enter the treated area until after the restricted-entry interval has passed. (EPA)
V. Ventilation

Greenhouses are structures enclosed with a nonporous covering. This makes ventilation an important consideration when spraying pesticides.

The EPA has established regulations for greenhouse spraying that require that ventilation continue until the air concentration is measured to be equal to or less than the inhalation exposure level that the labeling requires to be achieved.

If no inhalation exposure level is listed on the labeling, ventilation shall continue until after one of the following requirements has been met.

CAUTION! Pesticide or biocontrol recommendations made on any of the links from this page may not be legal in your state or country. Please check with your local county agent or regulatory official before using any pesticide or biocontrol mentioned on any of the links from this page.