Integrated Pest Management
George Kingston, President of the Western Massachusetts Master Gardener Association, gave a thought provoking presentation on the impact of personal gardens on the quality of the water in our communities at the Master Gardener Symposium last Saturday.
His talk was a reminder of the interconnectedness of all things, a principle that we gardeners are becoming more and more aware of. We often think of the polluters of our waterways being municipalities who dump untreated sewage into the rivers, or businesses who dump waste into streams, or farmers whose extra fertilizer runs off into nearby waterways, but homeowners also bear a measure of responsibility.
It is shocking to think that those who are devoted to their lawns use more fertilizers, pesticides and herbicides on their patch of turf than the American farmers who supply the produce sections of our supermarkets. Runoff from these lawns also goes into the storm drains, into the streams, into the rivers and finally into the ocean. Those chemicals can kill fish and other aquatic life along the way.
The first, and one of the best ways to protect our water ways is by judicious use of chemicals in the garden in a system called Integrated Pest Management or IPM. Using IPM principles on your domestic landscape will save you money and help create a safer, healthier garden.
We also want beautiful gardens and landscapes so how do we accomplish these goals, health, safety and beauty? First we have to observe our plants closely and carefully to detect disease or insect damage as early as possible.
The earlier damage is detected, the earlier it can be diagnosed and therefore easier to fix.
Once diagnosed, damage can be assessed. Is the problem cosmetic?. Mildew on the phlox is not attractive but neither is it harmful. No need for fungicides. If mildew really bothers you, maybe you should reconsider whether phlox is essential in your garden.
If the damage is more serious you can determine whether it is fatal. Even worse, you might find that it is a contagious problem. If the problem is contagious the plant should be removed and destroyed instantly. Do not put it into the compost pile where those disease pathogens will live to cause trouble another day. Most compost piles do not get hot enough to kill disease.
What is the root cause of the problem? Is the plant stressed by being too crowded? Is the site too shady, too sunny or too wet? Does the soil have the proper pH?
There are low impact controls for many problems, from handpicking destructive bugs, washing them off with a spray of water or insecticidal soap, pruning out damage, and digging weeds by hand.
If that does not solve the problem choose the right product for the specific problem. Broad spectrum herbicides and pesticides will kill a wide range of troubles, but they will also kill beneficial insects. Identify the particular bug or disease that is causing the damage and find the most specific remedy. Be very careful to use the product as directed. Use the minimum to accomplish your goal and treat only the affected plants. Store your herbicides and pesticides safely, and when they are outdated dispose of the excess properly. Many have a warning on the package that even the empty package needs to be disposed of carefully.
At the Saturday symposium we were talking about the problems that indiscriminate or heavy use of pesticides can cause in our own country. With that on my mind I was interested to see an editorial in the Sunday New York Times entitled Did Your Shopping List Kill a Songbird by Bridget Stutchbury, a professor of Biology at York University in Toronto and author of Silence of the Songbirds.
Stutchbury’s point was that the imported fruits and vegetables we find in our supermarkets in the winter often come from Mexico and South America where levels and types of pesticides that are used would be illegal in the U.S.
This had been a topic of discussion at dinner with friends on Saturday night, but the concern was more with how the pesticide residue on the produce might affect the eater. In fact Stutchbury says that “tests by the Centers for Disease Control show that most Americans carry traces of pesticides in their blood.” However, the focus of her editorial comes at the problem from a different perspective. She says these chemicals are killing the migratory birds like bobolinks, barn swallows and Eastern kingbirds that winter in that part of the world.
Once again we are back to the interconnectedness of all things. Her recommendation for a “bird friendly shopping list” is organic fair trade coffee, but Stutchbury says that melons, green beans, tomatoes, bell peppers and strawberries are rarely grown organically in Latin America. That brings us back to the value of eating foods that are in season and local.
And once again I am back in my own garden. There is no food more local than what I can grow myself. I am itching to get my hands in the soil again.
A final note. The Western Massachusetts Master Gardeners are a great group of people, passionate about gardening and about helping gardeners. They maintain a website www.wmassmastergardeners.org where you can get answers to frequently asked garden questions; if you still have questions they have an email question hotline. They are sure to have answers for you.
April 5, 2008