Question: There are so many types of weedkillers. How can I choose the correct one?
Answer: To choose the correct herbicide you need to answer three pairs of questions. (a) Is the weed an annual or perennial? (b) Is the weed a grass, or is it a non-grass (broadleafed) weed? (c) Does the weed do most of its growing in the cool months or during the warm months? If you can answer those three pairs of questions, you and your nurserymen will be able to choose the most appropriate weedkiller. Pre-emergent weedkillers, for example, will control annual weeds so long as you apply them before the weed seeds start to sprout. Early spring and early summer applications will prevent the warm-season annual weeds. Early fall applications will prevent the cool-season types. There are types for both grassy and broadleafed weeds. On the same line, there are post-emergent weedkillers for both grassy and broadleafed weedkillers. Your nurseryman can steer you in the right direction. Total-kill herbicides eliminate all vegetation, and there are specific weedkillers for nutsedge as well.