RM43 is one of our favorite products and for good reason. Made with 43 percent glyphosate, this product packs a seriously powerful at eliminating weeds and grass and keeps them from returning for up to 12 months (yes, 12 months). RM43 is effective on brush, vines and more than 150 weeds including the really tough ones like kudzu, poison ivy and poison oak and many more. We get a lot of questions about RM43 so we thought we’d share a couple. 

How is RM43 different from Roundup? 

RM43 contains both glyphosate and imazapyr, unlike Roundup which only has one active ingredient, glyphosate. Because of RM43’s formula, it binds to the soil to prevent the regrowth of weeds for up to a year. For more information, please read the complete label. But if you do like Roundup-type product, consider using our Compare-N-Save Weed and Grass Killer which contains 41% glyphosate. 

Is there water in RM43?  

There is no added water in RM43 as it is a concentrate, but we do like to use a lot of water when it’s put down. Our instructions have two rates you can use—one is a simple spot treatment rate of 6 ounces in one gallon of water. The other is 7.4 ounces of chemical in 1 to 10 gallons of water to cover 1,000 square feet. With the second rate, you should put down 7.4 ounces of chemical per 1,000 square feet using as much as 10 gallons of water. We like to use a lot of water. What we do is mix 7.4 ounces in 10 gallons and then spray it all over 1000 square feet—that is a lot of water on such a small area but it does a good job of getting through the vegetation and the gravel at that rate. Call us at 800-264-5281 if you have any further questions. 

Does RM43 kill perilla mint? 

Although not specified on our label, RM43 does kill perilla mint, along with a host of other plants not listed on our label. However, it is a complete vegetation control and will kill surrounding grass. We recommend spot spraying, as explained in this past blog on how to spray. We also suggest waiting two to three hours before letting animals graze in the area.  

What’s the difference between RM18 and RM43? 

RM18 kills the weeds while leaving fertile soil available for the plants you want–any product not absorbed by the plant will deactivate after it touches the ground. RM43 is total vegetation control and can work for up to 1 year. We have an article that goes into detail on the main differences between RM18 and RM43.  

What should I do if I left some RM43 out and it froze? 

RM43 should not be left to freeze, but if it does happen, shake it up well because in extreme cold the surfactant may separate from the mixture but it will easily go back into solution with agitation. 

Here are a bonus question and answer, where do you buy RM43? RM43 is both available in some stores, like Tractor Supply Co., and online from retailers like Amazon and Home Depot.