Quali-Pro Prodiamine 65WDG

Prodiamine Calculator (65 WDG Application + Mixing Rates)

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Written By: Mark Marino

a Massachusetts Core Applicator License holder and owner/operator of Lawn Phix,

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If you’re looking to prevent and control crabgrass, prodiamine herbicide is the best option. Prodiamine 65WDG by Quali-Pro is a generic Barricade and is one of the most cost-efficient pre-emergent herbicides on the market.

When applied at maximum rates, prodiamine can provide season-long coverage. Depending on climate and region, Prodiamine 65WDG can last up to 8 months efficacy in the soil. The application rates are dependent on grass type and low/max rates. 

WDG stands for Wettable Dispersible Granules. Important: Prodiamine 65WDG is measured by weight, not volume. So when measuring mix rates, be sure to use a digital scale

To activate, Prodiamine 65WDG needs to be watered in within 14 days of application. With proper mix rates and when applied as directed, prodiamine creates a vapor barrier in the soil. This pre-emergent barrier is a root pruner/clubber, preventing grassy and broadleaf weeds from germinating.

For the best result, use split applications. Prodiamine will lose efficacy in exposed sunlight (photodegradation).  For cool-season grasses, apply low rates of prodiamine pre-emergent herbicide in early spring before soil temperatures reach 55 degrees and a second application 2-3 months after. Use our prodiamine calculator above to ensure you don’t exceed the maximum annual amounts. 

While prodiamine isn’t as effective as Dimension (dithiopyr) in controlling broadleaf weeds, it’s a more practical option for crabgrass control. 

Prodiamine, particularly the Quali-Pro 65WDG, is much more affordable than dimension. This 5 lbs. container covers between 9,000 – 44,000 sq. ft. (depending on grass type and application rates). 0.88 cents per ounce equate to just $0.17 – $0.73 per 1,000 sq. ft. 

For smaller lawns, this 5 oz. product from Yard Mastery is just $20 and will cover an area between 6,000 – 9,000 sq. ft. 

Prodiamine 65WDG Pre-Emergent FAQs

What is Prodiamine 65 WDG application rate?

Prodiamine 65 WDG’s application rates are between 0.185 – 0.83 ounces per 1,000 sq. ft. per application. The rates for larger mixes and applications are 0.5 – 2.3 lbs. per acre.

Note that the mix ratio for Prodiamine 65 WDG is dependent on grass type and length of efficacy desired. Refer to the Prodiamine 65WDG label for the exact amounts for your grass type.

How do you mix Prodiamine 65WDG herbicide?

Start with a clean tank and fill it with water to 1/4 of the desired amount. Add the recommended amount of Prodiamine 65WDG to the tank and agitate. Ensure the granules are dissolved. Fill the tank with the rest of the water and agitate to ensure that the herbicide is fully dissolved and suspended in the tank.

How soon can I apply Prodiamine 65WDG Herbicide after seed after seeding?

After seeding/overseeding, you must wait 60 days after germination or after your second mowing of new turf (whichever is longer) before applying Prodiamine herbicide.

How soon can I seed after applying Prodiamine 65WDG Herbicide?

Depending on your application rates, you will need to wait at least four months before seeding or overseeding after applying Prodiamine.

How to apply prodiamine pre-emergent herbicide?

Apply Prodiamine 65WDG in a backpack sprayer, handheld sprayer, or tank mix. Use at least 0.5 gallons of water per 1,000 sq. ft. and spray evenly across the turf. Prodimaine must be watered inn with at least 1/2″ of irrigation or rainfall within 14 days of application. 


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