The best way manage pests and diseases naturally is to keep the eco-system of your yard in balance. Monitoring trees and plants for signs of pests, managing irrigation systems to avoid over-watering and not creating habitats that encourage pests or rodents that can damage your trees. Plants that are stressed because they are competing for water or nutrients, damaged and unhealthy plants attract pests. Keeping your soil healthy, regularly cleaning up garden debris and mulching with organic matter will keep your plants healthy. A good yard maintenance routine and regular inspection is the best way to prevent problems with your trees.
Always choose disease resistant varieties of plant if possible. Also, try planting varieties that repel pests or attract their natural predators.