What is a Pre-emergent Herbicide and How Will it Improve my Lawn?

What is a Pre-emergent Herbicide and How Will it Improve my Lawn?

Samuel Barrick

What is a Pre-emergent Herbicide and How Will it Improve my Lawn? Barricade, Dimension, Pendulum, ect. 

Ever wondered how some yards just stay completely weed free and healthy all year round? You might think they are paying a high price for a professional turf service to maintain their lawn. While most do, having a weed free lawn yourself can be done with a good plan and lawn maintenance program. 

The first step to a successful lawn program is preparing your lawn against invasive weeds. Along with a healthy stand of grass, pre-emergent herbicides are the best way to keep weeds out before they even come. 

What do I mean? A pre-emergent herbicide works by preventing newly germinated seed from developing by inhibiting growth of the root, the shoot, or both. Depending on the pre-emergent you choose, pre-emergents work by stopping root development or by burning the roots. 

The most common pre-emergent herbicides used in lawn care are Barricade (Prodiamine), Dimension (Dithiopyr), or Pendulum (Pendimethalin). Barricade is usually chosen due to its longevity and affordability. 


The Science Behind the Pre-emergents 

Barricade is part of the dinitroaniline class of chemicals that acts by inhibiting root growth of developing seed. It was originally created in 1987 to be used in fields of soybeans, cotton, and alfalfa. Barricade is part of the Group 3 Herbicide classification and is safe to users. 

Due to its longevity, one application can last up to 5 months at a safe rate for turf if certain environmental conditions are met. Depending on the label of the product, it can be used on golf courses (excluding greens), landscape ornamental, residential turf, and sports turf.  

Barricade is most effective on grass plants like poa annua, goosegrass, crabgrass and does well on some broadleaf weeds. 

Along with many other herbicides, Barricade is broken down by microbial activity and environmental conditions over time. This allows the product to be reduced enough to reseed with desirable grass after the recommended months on the application rate have elapsed. 


Dimension works by inhibiting root growth causing root elongation from happening. Dimension is a pyridine herbicide, but has a similar mode of action as Barricade. It is also a Group 3 herbicide and is safe to users. 

What sets Dimension apart from its competitors is its ability to control early stages of plant growth. For example, it can kill crabgrass prior to tillering (spreading out). If you are late on a pre-emergent application, Dimension is a good option if young crabgrass has already started to germinate. 

Dimension can be used in residential turf, commercial turf, landscape ornamentals, nurseries, and golf courses. It can be bought in liquid, Wettable Soluble Powder (WSP), or granular formulations.  


Pendulum is also part of the dinitroaniline class of chemicals like Barricade, and is a group 3 herbicide. Pendulum has a more exhaustive list of weeds controlled than Barricade and Dimension, but the longevity of Pendulum is the downside. 

Due to its extensive list of weeds, many applicators use it in landscape ornamental areas. It can also be combined with Roundup or Finale for control of existing weeds along with its pre-emergent control. 


Which Pre-emergent Should I Chose? 

There are different factors involved in choosing a pre-emergent like how long do you want it to last, what weeds you are trying to control, or where the application is going. Having a good grasp of the strengths and weaknesses of each pre-emergent will help inform your decision. 

Along with choosing what pre-emergent to use, choosing what formulation of the product is important. Most pre-emergents come in granular, liquid, or water soluble. Depending on your equipment, knowledge of application, and where you are applying it, we can inform you of what the best formulation is for your scenario. 

Cost is another factor when choosing a pre-emergent. The cost of each product can change depending on the formulation you buy it in and the quantity. A two-and-a-half-gallon jug of Prodiamine 4L has a high upfront cost but depending on your application rate can cover over eighteen acres. If you have a small lawn, you will never use that much. 

No matter which pre-emergents you choose, they will all do a good job. Pre-emergent are usually applied in early spring to control crabgrass throughout the summer. 

In a future post, we will look at when you should apply a pre-emergent based on your area and soil temperatures. 


Need some Pre-emergents? 

We have you covered.  

Check out our whole list of pre-emergents that we sell on our website here: 


Or below are links to the three we mentioned in this post: 

Barricade- https://www.lawnandpestcontrolsupply.com/collections/weed-preventer/products/barricade-4fl-herbicide-1-gallon 

Dimension- https://www.lawnandpestcontrolsupply.com/collections/weed-preventer/products/dimension-2ew-herbicide 

Pendulum- https://www.lawnandpestcontrolsupply.com/products/pendulum-aquacap-herbicide-2-5-gallon?_pos=1&_psq=pendulum&_ss=e&_v=1.0 


Want to learn more? Check out our sources: