Potential customers often ask the question, "When is the best time to spray for spiders?". Our answer- anytime. Particularly it's best from late August to November when most spiders are coming into homes. In Utah, for instance, towards the end of fall spiders go into hibernation, just like bears. As for ants, they colonize in walls or live well below the frost line. During the winter months we winterize homes by sealing exterior openings with silicone, expandable foam, or copper mesh. Sealing openings, AKA exclusion, is the best form of pest control. If there's no entry point, they won't get it.
The best time to get your lawn fertilized in the Salt Lake City area is after Halloween and before Thanksgiving. It's a short window. What you are looking for are 3-4 good frosts on the lawn. We apply the fertilizer during the afternoon and later in the day when the lawn is nice and dry. Our commercial grade lawn fertilizer has an overall better blend that penetrates well into the soil all winter long. When Spring arrives you have a rich, green, weed free lawn to start off the season. The November treatment is the most important out of the 4 step program for lawn fertilization. If you only choose one to do, make it the fall treatment.