If you’re constantly weeding your Phoenix or Anthem area yard, you may want to consider using a pre-emergent treatment to control the problem. These types of herbicides are applied to stop weed seeds from growing and act very differently from the weed killer sprays used after weeds have emerged. We answer the most frequently asked questions about pre-emergent herbicide use below, including what it is, when it should be applied, if it harms your other plants, and more. What is pre-emergent weed control? The answer is in the name – pre-emergent is applied BEFORE weeds appear. This type of liquid herbicide works to prevent weed seeds from growing . How does pre-emergent herbicide work? Contrary to popular belief, pre-emergents don’t prevent seeds from germinating . Instead, they prevent a germinated seed from growing any further. Once a seed has germinated, its root absorbs water from the surrounding soil....