Dimension vs Prodiamine- The Great Debate!

Dimension (Dithiopyr) vs. Prodiamine

While we are still in the heart of winter in many locations across the U.S., spring and the start of a new season is just around the corner. Each year signs of spring bring lots of energy and excitement to our industry. It’s a fresh start with lots of opportunity, but also some new challenges. For lawn care operators (LCO’s) the success and kick off to their entire season begins with pre-emergent herbicide applications in the spring. Austin Marsteller, Central’s Chemical Category Director, is here to walk you through the ins and outs of pre-emergents below so you can get ahead!

From Austin:

Regardless of what pre-emergent product you apply this spring, I was once told this perspective that has always stuck with me and something I want our customers to think about every pre-emergent season when reflecting on their upcoming program. Transform yourself to a farmer for the moment. A farmer may only have 30-40 seasons (years) in a career to plant their seed correctly in the fields, care for it and reap its rewards at harvest. However, much of this success is defined early on in the crucial planting season. A bad or missed planting season sets that farmer back and may even jeopardize the ability to harvest a crop that year. For an LCO, the pre-emergent application in the spring is no different. Whether you are an applicator or the business owner you only have so many Spring seasons (years) to set your season off right with a good pre-emerge application. It can truly define the success of the season ahead!

When it comes to pre-emergent herbicides in the market the two products that often come to mind and are used most often are Dimension (Dithiopyr) and Prodiamine (multiple trade names). This article serves to compare and contrast these two pre-emerge active ingredients and help you make an informed decision on which product choice may be best for your program.


Formulation– Both Dimension and Prodiamine are available in liquid, wettable powder, and on combination fertilizer formulations that will fit a preferred application method of your choice. A potential negative characteristic of Prodiamine is that causes yellow staining to equipment and/or the application site. Dimension is non-staining.

Mode of Action (MoA)– This is a time for a great point of clarification. Maybe you have been told or have seen somewhere about “rotating” Dimension and Prodiamine every so often to “change the chemistry up”. Rotation of chemistries comes into play when trying to avoid resistance (which is important), but in the case of Dimension and Prodiamine they are both Group 3 Herbicides. Therefore, just switching from Prodiamine to Dimension or Dimension to Prodiamine is not rotating the MoA. Where they are different is in their chemical families. Prodiamine is a Dinitroanaline (DNA) and Dimension (Dithiopyr) is a Pyridine.

Rates- For Prodiamine the maximum application rates will vary depending on the type of turf but in general cool season turf species are in a range of 10-24 fl. oz per calendar year where as warm season turf species in the 21-48 fl. oz per calendar year. Please always refer to the label for specifics. This leaves the ability for ~2 applications (depending on rate) per year. Dimension’s rate range across almost all cool and warm season grass varieties ranges from 1-2 pints/acre per application with no more than 6 pints/acre per year allowed (~3 applications, depending on rate).

Reseeding– Both Prodiamine and Dimension will inhibit the development of turfgrass when overseeded too soon after an application. For Prodiamine applications in Northern cool season turf predominate areas this interval can be anywhere from 4-6 months depending on the rate. In warm season turf predominate areas this range will vary even more greatly because of the higher and broader rates with reseeding intervals of up to 4-12 months. Dimension has reseeding intervals of 3-4 months depending on whether applications were made as a single application or sequential applications. This is very important to consider depending on the longevity of your season and reseeding programs.

Watering-In and Activation Periods– All pre-emergent products need to be incorporated with water at some point to become activated in the soil. This activation period can be very different among the pre-emergent active ingredients on the market. Beyond Prodiamine and Dimension this is important to consider when making any of your pre-emergent product selections especially if you are relying only on natural rainfall to do so. Prodiamine labels will state that weed control is most effective when activated by at least 0.5 inch of rainfall or irrigation before weed seeds germinate and within 14 days following application. Dimension labels state the product is most effective when activated by 0.5 inch or more of rainfall or irrigation and to optimize control ensure that activation has occurred prior to germination of most grass and broadleaf weeds. While the goal is to get both these products watered in sooner rather than later so they can begin working for your program just note there is no actual hard deadline to get Dimension water in. This could be an advantage in areas where natural rainfall is scarce or difficult to plan applications around.

Weed Control– When we think of Dimension and Prodiamine the first thought is pre-emergent control for crabgrass. We will dive into that shortly, but I always like to remind LCO’s that these products also pre-emergently control many other grasses and small seeded broadleaf weeds. Dimension will have a slightly broader weed spectrum compared to Prodiamine in what it controls pre-emergently and is important to consider in your program. Let’s move to the big topic of crabgrass. Both Dimension and Prodiamine are very effective at controlling crabgrass when properly applied and at the correct rates as a pre-emergent program. Where Dimension begins to separate itself from Prodiamine is Dimension’s ability to not only control crabgrass pre-emergently, but also at an early post stage. In cool season turf predominate areas early post-emergent control of crabgrass can be obtained up to the 5 leaf stage. In areas where warm season turf species are predominating Dimension has demonstrated post-emergent control of crabgrass through the 3-5 tiller stage. Dimension’s ability to provide pre and early post- emergent control of crabgrass gives tremendous flexibility in your program and is a major advantage for Dimension applications in the Spring.

At the end of the day, both Prodiamine and Dimension are very effective pre-emergents for controlling crabgrass when properly applied. However, after reading this article hopefully you discovered ways in which they are also different. A few of these differences included, maximum use rates, reseeding intervals, watering-in requirements, weed spectrum, and application flexibility (in reference to the pre and post activity of crabgrass with Dimension). When trying to decide on Prodiamine vs. Dimension it is important think about your individual business situation and program. At Central Turf and Irrigation, our team of subject matter experts is here and ready to help support you in making that decision.

*Please carefully read and follow all label instructions.

About Austin Marsteller

Austin has a decade of experience in the Green Industry, a degree in Turfgrass Science from Penn State University and an MBA from Louisiana State University-Shreveport. His career has been heavily focused in turf and ornamental on the manufacturer side, and most recently in agriculture specifically in bio stimulants, adjuvants, and specialty fertilizers. Austin works closely with all the employees and partners of Central to provide superior service and solutions to our turf and ornamental customers.