by Dave Tamayo,
Pesticide Control Program Manager,
Sacramento County Stormwater Program.
The way you design and maintain the landscaped areas of your home or business can either help or hurt local creeks and rivers, and the creatures that depend on them. Landscapes have the potential to trap pollutants, conserve water, and prevent creek erosion. However, poorly designed and maintained landscapes can waste water, cause soil erosion, and discharge toxic levels of pesticides and other pollutants.
One of the biggest water quality problems in our local area is the level of pesticides that are discharged from the urban environment. The Sacramento Stormwater Quality Partnership (a collaboration of the County of Sacramento and the Cities of Citrus Heights, Elk Grove, Folsom, Galt, Rancho Cordova, and Sacramento) and other public agencies have found through extensive monitoring that local creeks frequently contain the insecticides diazinon and chlorpyrifos at levels that will kill the insects and crustaceans that form an important part of the food chain.
Maintaining healthy plants is crucial to avoiding the use of pesticides in the landscape. As expert gardeners know, the best way to do that is to use a holistic approach that includes proper plant selection, soil conditions, watering, pruning and other maintenance chores.
Plants that are ill-adapted to the Sacramento area, or to the specific conditions where they are planted, will fail to thrive without heroic efforts to prop them up. Too much shade, seasonal temperature stress, incompatiblity with other plants, poor drainage, and other environmental factors can all weaken a plant and make it more vulnerable to insects and diseases. Often, the gardener is better off replacing a problem plant, or moving it to a better location, rather than spending lots of effort and money, and creating more pollution in the process.
Establishing and maintaining a healthy soil is also a key to success. Some soil additives, such as organic material, nutrients, and trace minerals may be necessary to establish good growing conditions. However, in many instances, over reliance on chemical fertilizers, especially those that also contain weed killers and insecticides, can actually harm your soil and its ability to support healthy plants.
Pesticides should never be used unnecessarily, but unfortunately they often are. For instance, some products are marketed in the Sacramento area to control lawn insects, which are very seldom the cause of the problems encountered in local lawns. Many weed problems can be solved on a long term basis by better plant selection, use of mulch and weed cloth, and even lawn mowing and watering practices. Some bug “problems” really aren’t harmful to the plants at all, and don’t need to be “solved”. And many less toxic, but effective pesticides are widely available, when they are needed.
Gardeners who apply these principles often get great satisfaction from having a better understanding of how their garden works, as well as benefiting from healthier plants, a cleaner environment, and reduced exposure to toxic pesticides.
The Sacramento Stormwater Quality Partnership supports and partners with various programs to provide easy access to detailed information and assistance:
UC Master Gardeners: (916) 875-6913
UC Davis: UC Davis Integrated Pest Management
Clean Water Business Partners
Bio Integral Resource Center:
Our Water Wise site:
This article originally appeared in our Fall 2004 Newsletter