At Chesterfield Lawn Services we have three main ways we help control weeds. First is a focus on the foundational health of the lawn, second is a pre-emergent, and finally is a post emergent. There are not tricks to get rid of weeds within one season, unless you go spray them every day that they start to grow. This is because each square yard can contain anywhere from zero to 1,000,000 seeds within it, which can stay dormant for up to 5 years before they start to grow. *1 This means that no matter how much pre-emergent or post-emergent we put down there will still be some weeds that get through. But there is hope if you keep reading.
Proper Lawn Maintenance
In our fertilizer page we went into the importance of a good base soil foundation (read here) so we will not go over it again. But the first step after the soil is addressed is proper lawn maintenance. We send out news letters (Sign Up Here) addressing this to remind customers about what is important at certain times of the year. But the main parts are ensuring that the grass is cut at the proper height (3.5-4 inches), that weeds are not able to grow to a mature state producing more seeds, and making sure that you have the right type of grass (sun/shade) which will out perform the weed growth; eventually choking out the weeds because the lawn is growing so good.
This treatment only works late winter and early spring since it creates a barrier to prevent weeds from even breaking the surface of the lawn. As illustrated in the image the yellow line is the application of pre-emergent which would create a barrier for any new growth. (If you are redoing your lawn in the spring you CAN NOT use pre-emergent since it will also prevent new grass seed from growing). In the spring the weed seed will germinate, start to grow, but once it hits that barrier it will kill the weed before it even pops out of the ground.
Since no application of pre-emergent is ever 100% effective then there is are two post emergent applications within the weed control program. We change up which type of chemical we use in order to prevent creating a resistant strain of weeds that will then take over the entire yard. We use two types of applications during the spring/early summer. One is a granular application to treat the entire lawn, and the second is a spray application focusing on just the areas that have a large amount of weeds in it.
There are two things that we stress to new customers. First is this is a process and it takes time to establish a great looking lawn, year after year. Second is that there are factors outside of our control that will affect your lawn. For example mowing too low during the summer will cause the lawn to go dormant to protect itself. Not watering the lawn during a dry spell of weather will again make the grass start preserving itself by going dormant (it will quickly come back with watering). Also if you allow weeds to grow to maturity by not mowing on a consistent basis then the weeds will keep coming back year after year because the weed seeds that will be put back into the soil.