Making the decision to go organic as opposed to synthetic in spraying your apple trees involves several factors. There is no point in going organic if you are not prepared to stop using herbicides around the trees and to stop using synthetic lawn fertilizers near the trees. The tree will take up the synthetic fertilizers as rain water washes down to the roots and your apples will no longer be considered organic. Since the organic spray is going to work in sync with nature, you will need to educate yourself about how nature takes care of pests and diseases by enhancing the health of your trees and the soil in which they grow. This process takes time to become effective, but will help the environment.
Organic gardening is no longer a new method of growing plants. Plenty of information is available for your education on the subject, such as that found at the Organic Materials Review Institute online. Changing your methods of pest control on apple trees to organic control requires information and new suppliers for your sprays. Without this education, you run the risk of damaging your apple trees because the organic method requires several simultaneous practices of fertilizing, pruning, spraying, weed and pest control.
Organic sprays are typically natural products. According to David Granatstein, of the University of Washington, "the standards allow use of natural methods and products and disallow use of synthetic methods and products." The Organic Materials Review Institute, OMRI, was organized to provide a list of certified products that are produced under the guidelines set forth by the USDA. If you are not sure if a product is labeled correctly as organic, you can plug it into the search engine and get instant results.
Growers realize the benefits from organic gardening initially within just one or two seasons and even more as the years pass and the land is restored to its natural state. More people are choosing to buy organic apples (ref 4), and more workers prefer working on trees that have not been sprayed with chemicals(5). Natural predators and insects will return to balance the ecosystem.The health improvement to the whole environment of apple farming will encourage a new generation of educated apple growers.
The schedule for spraying apple trees with organic sprays is similar to the old way of spraying, except that growers spray more frequently. Natural products such as sulfur, oil and lime sulfur are applied until petal drop and then every 10 days an application of different combinations of sulfur, pyrethrum and Bacillus thuringiensis. Mark Longstroth, of Michigan State University Extension, lists a suggested schedule of organic sprays for the growing season.
Although you might think that a spray is the only effective method of pest control, realize that a vigorously growing tree will not be as affected by a few pests as one that is weak. Keep your apple tree well-pruned to encourage airflow and sunlight penetration. Provide cardboard collar nests around the trunk of the tree for moths that might normally nest in the bark of your apple tree, and then throw away the cardboard collar when you see nests in the corrugated paper. Add compost to the soil to give the tree nutrients. Water your tree from above to wash off pests. Plant wildflowers to attract beneficial insects nearby. Combine these methods with organic sprays and you should have beautiful organic apples.