Though it is quite essential to keep spraying pesticides on your plants for better health and growth, also, using insect control spray is not a one-time application. It would be best if you keep applying it several times throughout the year because different pests appear at different times throughout the spring and summer. So, it would be best if you would apply the insect control pesticides in early spring, early summer and fall to avoid the mess. However, the fall season is considered the best season to spray your yard for crawling insects such as ants and water bugs. In addition to spraying around the foundation, spray a 2-4-inch band of soil to prevent insects from borrowing.