By Ruth Ann Hales, Colorado State University Cooperative Extension agent, horticulture
Ecosystem gardening is new idea that helps homeowners design a garden using ecological principals to reduce the amount of pesticides needed.
Three principles govern ecosystem gardening:
Grow a diversity of plants
Most suburban homes feature fewer than ten different species of plants in the entire landscape when at least 30 would be more appropriate. When landscapes are too simplified, various ecological imbalances can occur. An often-seen imbalance occurs when a large number of "bad" insects are present with a relatively small number of "good" insects. This can easily happen if the landscape consists mainly of non-flowering plants, such as lawn and evergreen shrubs.
Healthy ecosystem gardens contain a variety of plants that flower throughout the seasons. Flowering plants attract beneficial, "good" bugs that often prey on "bad" insects such as aphids and spider mites. Without flowering plants to attract beneficial insects into the garden, pest populations can multiply unchecked by natural controls. When this occurs, the only control method may be to spray with pesticides.
The right spot for the right plant
Pinyon pines are well adapted to Colorado and are an excellent choice for most landscapes. Planting a pinyon in a Kentucky Bluegrass lawn, however, is planting the "right' plant in the "wrong" place. To keep the lawn green and healthy, the pinyon pine will be overwatered. Overwatering encourages attacks by the pinyon pitch mass borer. Gooey masses of pitch oozing from branch joints often is a sign that a pinyon has been attacked by this insect.
Grow plants adapted to this climate
Birch trees, while elegant, are not as hardy in Colorado as pinyon pines. They also do not grow well in highly alkaline native heavy clay soil. Further the low humidity in Colorado puts additional stresses on this tree. Once birch trees become stressed, they often are attacked by the bronze birch borer. Limbs on these graceful trees begin to die back. After several years of borer attacks, birch trees look anything but beautiful.
Photograph of Birch tree courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010