There is no one-size-fits-all answer to this question, as the best insecticide for a specific plant will vary depending on the type of plant, the climate where the plant is located, and other factors. However, some general tips on choosing the best insecticide for plants include considering the target pests or diseases that the insecticide is intended to control, its toxicity to other plants and animals, and how effective it will be at controlling those pests or diseases.