One aphid or a couple of mites do not warrant major spraying. A few holes in the leaves can also be tolerated. This means you have to monitor your landscape on a regular basis, he says. Take note when small problems start to build and may need to be controlled. Record problems and specific areas for future use.
Experience indicates that problems and insects strike about the same time each year.
Next year's problems will be easier to control if you are aware they are coming. Also, avoid plants that are especially troublesome. Do a little research before planting trees and shrubs. Certain plants may look great, but come with a multitude of inherent problems. Aspen trees are a great example.