While using pesticides or herbicides to keep trees healthy may be a solution in the short-term, it is likely not the best long-term option. Pesticides and herbicides can have harmful effects on both humans and wildlife, leading to ecological disaster. Additionally, they are often expensive and difficult to use correctly – meaning that they will likely need to be repeated more frequently than necessary.
When it comes to keeping trees healthy, there are many alternatives that are simpler, cheaper, and easier to use. These include fertilizing with organic matter (such as manure), watering properly according to soil moisture levels, applying shade via tree canopy coverages or wall covering systems, controlling pests with natural remedies like garlic or neem oil sprays etc., and planting trees that are adapted for your climate zone.
Ultimately, whether you choose pesticide/herbicide usage or another approach depends on the specific situation at hand. But always remember: Everything has its limits.