We talk to a LOT of people this time of year about pre-emergent applications, and something that comes up every once in a while is “I put out a pre-emergent and it didn’t work…what did I do wrong?”.
There are a number of factors that could come in to play such as application rate, using the right products, complete coverage etc.
However, there are two primary reasons or mistakes that we see more than anything else.
First, the product never actually comes into contact with the seeds. Remember, we are trying to kill the seed before it germinates. That will not happen if the product never touches the seed. That is why the application has to be WATERED IN. The seeds are down in the soil, and watering in the application will soak the product down into the soil. When you skip the watering, the pre-emergent is simply resting on top of your lawn, allowing the seeds in the soil to germinate and grow into weeds.
In other words, if you don’t water in your application, IT WILL NOT WORK.
The second reason as to why a pre-emergent “doesn’t work” is not necessarily a mistake that was made, but more of a misunderstanding. When someone applies a pre-emergent now but still has weeds popping up over the next month, the tendency is to blame the pre-emergent.
What you have to remember is that pre-emergents are all about what is going to happen 3 to 6 months from now. The weed situation in your lawn right now, and over the next 4 to 6 weeks, is a result of what WAS or WAS NOT done months ago.
So don’t make the mistake of blaming the pre-emergent you JUST put out for the weeds you have right now. Pre-emergents do work, the results will come, you just have to wait for them!
