Pendimethalin Vs Prodiamine: We Explain The Difference!

pendimethalin vs prodiamine

Do you know the difference between pendimethalin and prodiamine? If not, don’t worry! I’m going to explain everything.

Pendimethalin and prodiamine are both herbicides, but each has unique uses.

Pendimethalin is mainly used for pre-emergence weed control, while prodiamine is mainly used for post-emergence weed control. Pendimethalin is also cheaper than prodiamine and works great as a granular application.

However, they are both effective at killing weeds! So how do you decide which one to use? Read on.

What Are The Differences?

The main difference between pendimethalin and prodiamine is their method of application. Pendimethalin is applied before the weeds germinate, while prodiamine is applied after the weeds have germinated.

Pendimethalin creates a barrier on the surface of the soil that prevents weed seeds from germinating. Prodiamine, on the other hand, works by killing the weed’s root system.

Pendimethalin is also more effective on larger weeds, while prodiamine is more effective on smaller weeds.

Pendimethalin is best used in the spring before the weeds have a chance to germinate. Prodiamine is best used in the fall after the weeds have already sprouted.

When To Use Pendimethalin

Pendimethalin is ideally used in the spring, around mid-April, to be precise. This is because pendimethalin works best when applied before the weeds have a chance to germinate. 

That’s not to say you can’t use pendimethalin in the fall, but it will not be as effective because the germination process would be well underway, but if pendimethalin is all you’ve got, it’s better than nothing!

You’ll get the best results from pendimethalin when using it to control quite a wide range of broadleaf and grass weeds. It’s excellent again weeds like henbit, sandbur, and kochia.

One of the main negatives when it comes to pendimethalin is the short residual when compared to prodiamine. Every product will have specific instructions on the label, but you’ll likely have to put a second application down around 6 weeks after the first.

Grow Your Yard Tip
Don’t miss our article on the differences between dithiopyr and prodiamine.

When To Use Prodiamine

You’ll get the most out of prodiamine if you use it in the fall, or late summer, ideally for controlling any henbit outbreaks.

It will be far more effective than pendimethalin at this time of year.

Prodiamine will still give you some level of weed control in the spring, but it won’t be as good as pendimethalin applied before the weeds have germinated.

As I mentioned, prodiamine is incredible at dealing with henbit, but it’s also effective against crabgrass, goosegrass, spurge, and chickweed.

The main reason for the popularity of prodiamine is because of the long residual in soil. It will stay effective for up to 6 months, keeping any fall/winter germinating weeds at bay until next spring, just in time for your pendimethalin application!

Pendimethalin Application Rates

Talking of pendimethalin application, let me give you a bit of information about application rates.

Pendimethalin comes in both a liquid and granular form. It’s always best to follow the instructions on the product label, but I’ll give you a general idea here.

For pendimethalin in a liquid form, you’re looking at an application rate of 2-4 ounces per 1,000 square feet. For pendimethalin in a granular form, you’re looking at an application rate of 0.5-1 pound per 1,000 square feet.

Pendimethalin is best applied with a broadcast spreader to get even coverage.

Prodiamine Application Rates

Prodiamine also comes in both a liquid and granular form. Again, follow the instructions on the product label for the best results, but here’s my take.

For prodiamine in a liquid form, you’re looking at an application rate of 4-8 ounces per 1,000 square feet. For prodiamine in a granular form, you’re looking at an application rate of 1-3 pounds per 1,000 square feet.

Prodiamine is also best applied with a broadcast spreader to get even coverage.

My Recommendations

Pendimethalin Recommendation: Drexel, Liquid.

I’ve used Drexel on a few occasions now; it was recommended to me by a good friend that maintains a few local golf courses, so I trust their opinion.. and I’ve come to the same conclusion, it gets the job done, and is really easy to apply.

Now this will leave a nice yellowy stain on the inside of your sprayer, not the end of the world but, so you’re aware.

It also has quite a strong smell after application, but in terms of effectiveness, I can’t fault it.

Drexel Pin-Dee Pendimethalin, Liquid
  • 1.25 gallon Other Pin-Dee 3.3 herbicide functions and benefits are :...
  • Emulsifiable concentrate containing 3.3 pounds of active Pendimethalin per...
  • It is an herbicide for pre-emergence control of most annual grasses and...
  • It is use in Landscape and ground maintenance.
  • Active Ingredient: 37.4% Pendimethalin

Prodiamine Recommendation: Quali-Pro, Granular.

When it comes to prodiamine, look no further than Quali-Pro, it’s so cool to have a pre-emergent that actually works!

Now, this is granular, but you’ll be mixing it in your backpack sprayer. You’ll likely cover 1000 square feet with 3 gallons of the mixture, so it’s alright.

You can apply it on the ground and water it in, but I wouldn’t recommend it, you’ll get the best results with a backpack sprayer. You’ll likely have a settlement at the bottom of the sprayer, but clear it out and go again. I can’t recommend this product highly enough!

Quali-Pro Prodiamine, Granular
  • PRE-EMERGENT HERBICIDE: Quali-Pro's Prodiamine 65 WDG provides pre-emergent...
  • FEATURES & BENEFITS: Excellent tank mix partner with fertilizers and iron...
  • USE SITES: Nurse, Landscape, Turf, Trees, Golf Courses
  • EFFECTIVE AGAINST: Annual bluegrass (Poa annua), Henbit, Knotweed,...
  • ACTIVE INGREDIENT: Prodiamine 65%

Frequently Asked Questions:

How long is pendimethalin effective?

Pendimethalin will stay effective for 4 to 6 weeks. You should consider another application at around week 6, as the pendimethalin becomes less effective.

How long is prodiamine effective?

Prodiamine can stay effective for up to 6 months. It’s ideally used in areas where weeds haven’t yet sprouted, ideally at the beginning of the germination process.


So, there you have it!

It isn’t necessarily a case of pendimethalin vs. prodiamine, as they’re not in direct battle with each other, they’re both excellent at the jobs they’re created for.

If you’re looking to get ahead of the weed game before the summer hits, go for pendimethalin, just be aware you’ll need to apply it every 6 weeks.

If you’re in it for the long game, and you can wait until the end of summer, go for prodiamine. You won’t believe how effective it can be against even the most difficult of weeds!

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