Sustainable Landscaping
Your Subtitle text
Integrated Pest Management
When Rachel Carson wrote the book "Silent Spring" she was concerned about the dangers of pesticides being used and their long-term effects on the environment. She understood that many pesticides had a level of persistence in the environment that caused them to have unforeseen and undesired effects on non-target organisms.
Carson was a proponent of reducing the use of toxic chemicals as well as finding less-toxic means to control crop pests.
Since that time, scientists have undertaken extensive means to better target insect pests while avoiding damage to on-target organisms. Research into alternative pesticides and understanding pest life cycles have led to the development of an array of pest control measures that meet the criteria of being less toxic and reducing harm to non-target organisms.
Practices that are components of Integrated Pest Management are: cultural methods to avoid pest problems, using genetically improved plants for improved resistance to pests and diseases, scouting and monitoring for pests, developing pest thresholds and treatment thresholds, physical managment of pests, biological control methods, and use of less toxic chemicals.
A variety of IPM methods has been developed in the past 40+ years. Many techniques are specific to the crop or plant being grown. Pest scouting and setting thresholds are fairly unique for each plant species. It is important to refer to information for each plant species to determine the appropriate IPM measures. State extension service offices can provide good resource materials and should have specific information to guide both landscape professionals and homeowners.
CULTURAL METHODS
Some of the cultural methods that are most effective are those that avoid diseases and pests in the first place. This begins with selecting the best site for planting a particular species. In addition to sun or shade, and considering the maximum size a plant will attain, one must also know and understand soil conditions before planting in an area. For example, the soil pH (acidity or alkalinity) determines nutrient availability. Some plants, such as rhododendrons and azaleas, require a slightly to moderately acid soil. On high pH (alkaline) soils, leaves will be chlorotic.
Another cultural practice that affects plant health, particularly if it is not done properly, is pruning. This applies primarily to trees, but can also apply to shrubs. Some harmful pruning practices include topping of trees and making flush cuts. Topping trees is the practice of cutting large branches indiscriminately, rather than cutting medium or smaller branches back to a larger branch or bud. Flush cuts remove some or all of the branch collar, which is a protective zone found at the base of many branches. The branch collar should be left intact as it allows proper healing of the pruning wound. Pruning "tar" or other sealants have been found to have no beneficial effects, or even harmful affects. This is because they allow harmful micro-organisms to remain vital in the moisture retained in the wound area, increasing the chances of rot. The healing process of trees does not rely on sealants.
Another cultural method is proper fertilization to grow a healthy plant. Any application of fertilizer should be made with knowledge of the soil nutrient status, which can best be obtained by a soil test.
Fertilizing properly at the correct time during the year is critical for the long-term health of perennial plants such as woody plants and lawns. The best time to fertilize plants is at the beginning of their growing season. This time differs, depending on your geographical location. For cool season turfgrass, such as Kentucky bluegrass, the spring and fall are the two primary growing seasons. For warm season turfgrass, the summer is the main growing season. Trees in temperate cliamtes have a growth spurt in the spring, and a second one in summer. Roots will often continue to grow on many plants, as long as the soil isn't frozen. Nitrogen is required for leafy, vegetative growth, while potassium aids in root growth.
SOURCES AND FURTHER READING
Dreistadt, S. H., J. K. Clark, and M.L. Flint. 1994. Pests of landscape trees and shrubs: an integrated pest management guide. University of California, Div. Agri. And Nat. Res. Oakland, Ca. 327pp.
Orton, D. and T. Green. 1989. Coincide. Plantsman's Publication. 189pp.
Schrock, D. et al. 2000. IPM and pesticide safety, in Illinois Master Gardener Manual. Univ. Ill. Extension. Champaign, IL.
Carson was a proponent of reducing the use of toxic chemicals as well as finding less-toxic means to control crop pests.
Since that time, scientists have undertaken extensive means to better target insect pests while avoiding damage to on-target organisms. Research into alternative pesticides and understanding pest life cycles have led to the development of an array of pest control measures that meet the criteria of being less toxic and reducing harm to non-target organisms.
Practices that are components of Integrated Pest Management are: cultural methods to avoid pest problems, using genetically improved plants for improved resistance to pests and diseases, scouting and monitoring for pests, developing pest thresholds and treatment thresholds, physical managment of pests, biological control methods, and use of less toxic chemicals.
A variety of IPM methods has been developed in the past 40+ years. Many techniques are specific to the crop or plant being grown. Pest scouting and setting thresholds are fairly unique for each plant species. It is important to refer to information for each plant species to determine the appropriate IPM measures. State extension service offices can provide good resource materials and should have specific information to guide both landscape professionals and homeowners.
CULTURAL METHODS
Some of the cultural methods that are most effective are those that avoid diseases and pests in the first place. This begins with selecting the best site for planting a particular species. In addition to sun or shade, and considering the maximum size a plant will attain, one must also know and understand soil conditions before planting in an area. For example, the soil pH (acidity or alkalinity) determines nutrient availability. Some plants, such as rhododendrons and azaleas, require a slightly to moderately acid soil. On high pH (alkaline) soils, leaves will be chlorotic.
Another cultural practice that affects plant health, particularly if it is not done properly, is pruning. This applies primarily to trees, but can also apply to shrubs. Some harmful pruning practices include topping of trees and making flush cuts. Topping trees is the practice of cutting large branches indiscriminately, rather than cutting medium or smaller branches back to a larger branch or bud. Flush cuts remove some or all of the branch collar, which is a protective zone found at the base of many branches. The branch collar should be left intact as it allows proper healing of the pruning wound. Pruning "tar" or other sealants have been found to have no beneficial effects, or even harmful affects. This is because they allow harmful micro-organisms to remain vital in the moisture retained in the wound area, increasing the chances of rot. The healing process of trees does not rely on sealants.
Another cultural method is proper fertilization to grow a healthy plant. Any application of fertilizer should be made with knowledge of the soil nutrient status, which can best be obtained by a soil test.
Fertilizing properly at the correct time during the year is critical for the long-term health of perennial plants such as woody plants and lawns. The best time to fertilize plants is at the beginning of their growing season. This time differs, depending on your geographical location. For cool season turfgrass, such as Kentucky bluegrass, the spring and fall are the two primary growing seasons. For warm season turfgrass, the summer is the main growing season. Trees in temperate cliamtes have a growth spurt in the spring, and a second one in summer. Roots will often continue to grow on many plants, as long as the soil isn't frozen. Nitrogen is required for leafy, vegetative growth, while potassium aids in root growth.
SOURCES AND FURTHER READING
Dreistadt, S. H., J. K. Clark, and M.L. Flint. 1994. Pests of landscape trees and shrubs: an integrated pest management guide. University of California, Div. Agri. And Nat. Res. Oakland, Ca. 327pp.
Orton, D. and T. Green. 1989. Coincide. Plantsman's Publication. 189pp.
Schrock, D. et al. 2000. IPM and pesticide safety, in Illinois Master Gardener Manual. Univ. Ill. Extension. Champaign, IL.
