We get asked all the time what is the difference between pre-emergent and broadleaf herbicides. It’s actually fairly simple. The short answer is that pre-emergents prevent weeds, while broadleaf herbicides kill already established weeds. Now, for the long answer for you research-driven individuals. Pre-emergents work by creating a barrier that inhibits germinating weeds from growing. This is why we talk about the importance of timing your pre-emergents so much. Too soon and the barrier wears down before it can be effective. Too late and the process has already happened. But if your timing is off, or you have some breakthrough weeds, general broadleaf herbicides are there to save the day. But, it is important to note, that broadleaf herbicides will only target weeds that have already popped up. It will be totally ineffective for weeds that have yet to sprout. Hope this helps and if you have any questions, let us know.