RM43 Herbicide: Long-Lasting Control and Prevention of Weeds

RM43 Herbicide
If you’re looking for a herbicide that not only controls weeds and unwanted vegetation but also provides long-term prevention, then you should try RM43.

This herbicide is unique because of its ability to prevent weeds, and it’s awesome because it gives you a long break from dealing with them.

In this article, I’ll get straight to the point on how this herbicide works and everything you need to know to quickly get started.

What is RM43 Herbicide?

RM43 is a total herbicide that can be used both as a pre-emergent and post-emergent treatment.

It can effectively control and prevent a wide variety of weeds. Also, as a total herbicide, it provides long-lasting control over weeds for up to one year.

RM43 Herbicide Active Ingredient

RM43 herbicide has two active ingredients in its composition:

  1. The first active ingredient is called glyphosate (43.68%). Glyphosate is a systemic non-selective herbicide.
  2. The second active ingredient is imazapyr (0.78%). Imazapyr is a systemic non-selective herbicide.

How does RM43 herbicide work?

RM43 herbicide works by targeting both the foliage and roots of weeds. The weed absorbed the herbicide. Once inside the plant, the herbicide takes over the weed system.

To put it simply, it kills the weeds in a systemic way from the inside out. This is because the herbicide contains two systemic herbicides: glyphosate and imazapyr.

Both of these herbicides inhibit the same amino acids that are vital for weed growth, leading to the plant’s death.

When to apply RM 43 herbicide

RM43 herbicide can be applied during the summer or at the end of spring. It is effective as both a pre- and post-emergent weed killer, meaning it can be used on germinated weed seeds as well as fully grown weeds.

What else to keep in mind about the period of applying this herbicide:

  • You can apply the herbicide to germinated weed seeds before the weeds become visible when the area is still bare-ground.
  • You can apply RM43 herbicide on fully-grown weeds, but for best results, I suggest you mow them down if they are taller than 6 inches.
  • After removing the debris, wait for another two weeks to allow the weeds to regrow before spraying them with the herbicide.
  • In the case of woody vines and brushes, you should spray them in late summer.

How to apply RM43 Herbicide

Proper preparation is crucial when applying RM43 herbicide. It is vital to mix the herbicide in a controlled environment, using appropriate equipment and following all safety guidelines and precautions.

Here are the steps to apply the RM43 herbicide:

  1. The first step is to check the weather conditions. It is recommended to apply RM43 herbicide when temperatures are above 60°F and wind speed is below 10 mph. One advantage of this herbicide is that you don’t have to worry about rain. It is a non-selective pre- and post-emergent herbicide that is rain-resistant within one hour of application.
  2. Ensure that you are fully equipped with the appropriate personal protective equipment (PPE). Your PPE must be clean and should include protective eyewear such as goggles, a face shield, or safety glasses, a long-sleeved shirt, long pants, socks, shoes, and chemical-resistant gloves.
  3. After you’re fully prepared, you have to make sure to use only materials that are resistant to the product.

    These materials include barrier laminate, butyl rubber with a thickness of at least 14 mils, nitrile rubber with a thickness of at least 14 mils, neoprene rubber with a thickness of at least 14 mils, natural rubber with a thickness of at least 14 mils, polyethylene, polyvinyl chloride with a thickness of at least 14 mils, and Viton with a thickness of at least 14 mils.

  4. The next step is to prepare the right herbicide applicator. You can use a backpack sprayer, pump-up sprayer, sprinkling can, an ATV, or tractor-mounted sprayer.

Now, two application methods can be used for this herbicide, and I will explain how to apply them separately.

1. Total Vegetation Control or bare-ground

This method should be used when you want to control all vegetation in an area, leaving it bare and free of any growth, including both targeted and non-targeted weeds.

  1. Once you have prepared your applicator, you need to mix 7.4 fl. oz (0.46 pints) of RM43 herbicide with water. This amount of herbicide can be used to make 1 to 10 gallons of solution, which can cover up to 1,000 square feet.

    * The maximum application rate that you can use is 2.5 gallons per acre per year, which is 7.4 fl. oz. per 1,000 square feet per year.

  2. Agitate the solution by shaking or stirring the tank to ensure the herbicide is mixed evenly with the water.
  3. Spray the entire area where you want to obtain total vegetation control.
  4. When you finish spraying, clean the spraying equipment immediately after use, and wash all PPE thoroughly with soap and water.
  5. Wait at least one hour after application before any rainfall or irrigation.

2. Spot Control of Brush, vines, and weeds

  1. For spot control of brush, vines, and weeds you need to mix 6 fl. oz. herbicide per 1 gallon of solution.
  2. Stir or shake to ensure that the herbicide is evenly mixed with the water.
  3. Use the applicator and spray the solution uniformly on woody plants.
  4. Make sure to clean the spraying equipment and wash all PPE with soap and water.
  5. Wait at least one hour after application before any rainfall or irrigation.

In order for this method to work effectively, follow these tips:

  • Always apply the herbicide when woody weeds, such as brush, vines, and weeds, are actively growing.
  • Ideally, apply the herbicide in late summer or fall, as wood brush and vines are more easily controlled during this time of year.
  • Do not spray the plants if they have recently been mowed or cut. Wait until full leaf formation.
  • Avoid mowing the plants for at least 2 months after spraying them

Where not to apply the RM43 herbicide

RM43 herbicide should not be applied in some specific areas. Below you can find the restrictions on where you should not apply this herbicide. By following these restrictions, you can ensure that you will not harm the environment.

  • Do not apply the herbicide to wanted plants.
  • Do not apply it near lakes, ponds, streams, or any other water source.
  • Do not apply it to the desired trees’ roots.
  • Do not apply it on slopes in the landscape. The slopes can suffer movement and may harm other desirable plants located further down the slope.
  • Do not use on desirable lawns or turf.
  • Avoid applying RM43 herbicide on dry or light sandy soils, especially during periods of high wind speed. It’s recommended to settle the soil by watering it prior to application.

How to mix RM43 Herbicide

RM43 can be easily mixed with water for effective application, and its label provides clear instructions.

Let’s take a look at the RM43 mixing instructions:

  • before starting to mix the herbicide, make sure you wear the right personal protective equipment.
  • now, fill your sprayer tank with clean water to the desired level.
  • shake the herbicide container well before opening it.
  • measure out the required amount of RM43 herbicide as per the mixing instructions.

    But what about the RM43 mix ratios?In general, the recommended mix rate for RM43 is 7.4 fl. oz. of herbicide per 1 to 10 gallons of water.

    The exception is when spot-applying to woody weeds such as brush, vines, and trees. For these, the recommended rate is 6 fl. oz. per gallon of water.

  • after adding the herbicide, take the time to agitate the solution by shaking it thoroughly. This will ensure that the herbicide is mixed evenly with the water.

These are all steps for the right mixing of the RM43 herbicide. Now, you are to apply it.

Can RM43 be mixed with other herbicides?

RM43 is a powerful total herbicide that contains two active ingredients, making it highly effective at eradicating various weeds.

So, can you mix RM43 with other herbicides? No, I suggest you not mix RM RM43 with other herbicides as it can result in powerful or unexpected chemical reactions.

Its label does not name any herbicides that would be safe to be mixed with it. Therefore, it’s best to use RM43 on its own to ensure optimal results and avoid any potential negative impacts on the environment.

But what about surfactants for herbicides? Should you add surfactant to RM43?

No, you should not add surfactant to RM43 because it already includes surfactant in its composition. Adding surfactants or any other additives may alter the composition and effectiveness of the herbicide.

Overall, I recommend you use RM43 as a standalone herbicide to ensure maximum efficacy and avoid any unexpected reactions.

Reasons why may RM43 can fail

Although RM43 herbicide is a reliable tool in weed management, it can sometimes fail to work for several reasons.

Below, I will list five reasons why RM43 may not work:

  1. The herbicide may not be applied correctly.
    You should always use the correct rate. In addition, you should spray it at the right time as specified on the label. If you don’t follow the recommended rate or time, you may not see the results you want.
  2. The herbicide may not be mixed well with the water.
    You have to shake and stir the solution. The herbicide must be fully mixed with the water. If it is not, then its effectiveness will be reduced.
  3. The herbicide may not have been stored correctly.
    You want to make sure that the herbicide is stored in a cool, dark place away from direct sunlight. If it is not stored correctly, then it loses its properties. If it is not stored correctly, it may lose its effectiveness.
  4. You may not have followed the label’s instructions.
    For example, if the weeds are taller than 6 inches, the label states that you have to mow them, remove the debris, and wait for two weeks before applying the herbicide. If you do not follow these instructions, the herbicide may not work effectively.
  5. Too much rain after herbicide application can cause issues.
    While RM43 herbicide is rainfast within one hour of application, a heavy rainstorm shortly after application can wash the herbicide away.
Can you mix RM18 and RM43?

I know that I previously advised against mixing any herbicides with RM43. However, it is also important to understand why.

So, to answer shortly to the question, no, I recommend you not to mix RM18 with RM43 herbicide.

Now let’s understand why.

These two herbicides have different aims and are designed for different intentional purposes.

RM43 is a non-selective herbicide that eradicates everything it comes into contact with when sprayed. This is precisely why it’s important to be careful with it and follow label instructions.

On the other hand, RM18 is a selective herbicide that targets specific weeds without affecting desired plants.

Therefore, mixing these two herbicides may result in an ineffective or even harmful mixture.


How long does RM43 last in soil?

RM43 can last in the soil for up to 12 months, providing long-lasting control of weeds. However, the duration of its effectiveness depends on various factors, such as weather conditions, soil types, types of weeds, and the level of weed resistance.

Will RM43 kill trees?

Yes, RM43 will kill trees and any other desired plants and vegetation. If you want to ensure that your trees are safe, avoid spraying RM43 around them.

If you need to spray near them, build a protective barrier around the trees using plastic or other materials.

How long before RM43 is rainproof?

RM43 is rainproof within two hours after application.

How long does it take for RM43 to work?

It can take a few weeks for the RM43 herbicide to work. Keep in mind that it is a systemic herbicide, meaning that it must be absorbed by the plant and consumed by the plant’s system.

Therefore, it takes some time to see visible signs. It also depends on factors such as the type of weed, its size, and weather conditions. It can be that you see earlier signs of damage within a few on some weeds, while others may take a few weeks.

Is RM43 safe for pets?

RM43 is safe for pets, cattle, and other animals after it has completely dried up. This means that you can allow your pets and other animals to enter the sprayed area only after the herbicide has dried up completely.

However, it is important to note that animals should not consume any plants or grass that have been sprayed with RM43. Ingesting the herbicide can be toxic for pets and other animals.

So, if your pets like to eat grass, it’s important to keep them away from areas where RM43 has been applied.

Is RM43 the same as Roundup?

No, RM43 is not the same as Roundup. Although they are both non-selective herbicides, RM43 is much more powerful than Roundup.

RM43 contains two active ingredients and provides long-lasting weed control for up to a year, while Roundup only kills a variety of weeds without providing a long-lasting effect.

How long does it take RM43 to dry?

It takes two hours for RM43 to dry completely.

How to wash RM43 out of the soil?

To wash RM43 out of the soil, you can follow these steps:

  1. use a tool, such as a shovel, to remove any plants, weeds, or soil that has come into contact with the herbicide.
  2. use a hose to water the area thoroughly; this dilutes the herbicide.
  3. allow the area to soak for some time.
  4. continue to water the area repeatedly over the next week.
  5. if you want to ensure that the herbicide is completely removed from the soil just test the soil.
What is stronger than RM43?

Roundup Pro Max is stronger than RM43.

Although both herbicides contain glyphosate, Roundup Pro Max has a higher concentration of the active ingredient, making it stronger than RM43.

How soon can you plant after using RM43?

After using glyphosate RM43, planting should be delayed for a longer period of time compared to other glyphosate herbicides such as Ranger Pro. This is because RM43 contains an additional ingredient called imazapyr.

Although you can still plant after using RM43, it is recommended to wait a longer period of up to a year.

List with Weeds Controlled by RM43 Herbicide

Being classified as a total herbicide, RM43 herbicide can control a lot of types of weeds. That is why it is also known as a powerful solution for weed management.

RM43 herbicide can control weeds like kudzu, poison ivy, Johnsongrass, bahiagrass, bluegrass, bermudagrass, quackgrass, and many more which I will list below in Tables 1,2, and 3.

Table 1. Grass/Nutsedge Weed Species Controlled by RM43
Popular Name Scientific Name
Bahiagrass Paspalum notatum
Cogongrass Imperata cylindrical
Muhly, wirestem Muhlenbergia frondonsa
Quackgrass Agropyron repens
Bentgrass Agrostis spp.
Dallisgrass Paspalum dilatatum
Napier grass Pennisetum purpureum
Reed, giant Arundo donax
Bermudagrass Cynodon dactylon
Fescues Festuca spp.
Nutsedge; purple, yellow Cyperus rotundus
Cyperus esculentus
Ryegrass, perennial Lolium perenne
Bluegrass, Kentucky Poa spp.
Fescue, tall Festuca arundinacea
Orchardgrass Dactylis glomerata
Timothy Phleum pratense
Brome Bromus spp.
Guineagrass Panicum maximum
Pampas grass Cortaderia spp.
Torpedograss* Panicum repens
Bromegrass, smooth Bromus inermis
Johnsongrass Sorghum halepense
Panicum Panicum spp.
Vaseygrass Paspalum urvillei
Canarygrass, reed Phalaris arundinacea
Kikuyugrass Pennisetum clandestinum
Para grass Brachiaria mutica
Velvetgrass Holcus spp.
Cattail Typha spp.
Knotgrass Paspalum distichum
Phragmites* Phragmites spp.
Wheatgrass, western Agropyron smithii
Table 2. Broadleaf Weed Species Controlled by RM43
Popular Name Scientific Name
Alfalfa Medicago sativa
Fiddleneck Amsinckia spp.
Poison hemlock Conium maculatum
Alligatorweed* Alternanthera philoxeroides
Fleabane Erigeron spp.
Ragweed, common Ambrosia artemisiifolia
Anise (fennel) Foeniculum vulgare
Fleabane, hairy Conyza bonariensis
Ragweed, giant Ambrosia trifida
Artichoke, Jerusalem Helianthus tuberosus
Horsenettle Solanum carolinense
Smartweed, Pennsylvania Polygonum pensylvanicum
Bassia, fivehook Bassia hyssopifolia
Horseradish Armoracia rusticana
Smartweed, swamp Polygonum coccineum
Bindweed, field Convolvulus arvensis
Ice plant Mesembryanthemum crystallinum
Sowthistle, annual Sonchus oleraceus
Blueweed, Texas Helianthus ciliaris
Knapweed Centaurea repens
Spurge, leafy* Euphorbia esula
Bracken fern Pteridium aquilinum
Kochia Kochia scoparia
Starthistle, yellow Centaurea solstitalis
Bursage, woollyleaf Franseria tomentosa
Lantana Lantana camara
Sunflower Helianthus annuus
Clover, red Trifolium pretense
Lespedeza Lespedeza spp.
Thistle, artichoke Cynara cardunculus
Clover, white Trifolium repens
Lettuce, prickly Lactuca serriola
Thistle, Canada Cirsium arvense
Dandelion Taraxacum officinale
Milkweed Asclepias spp.
Thistle, Russian Salsola kali
Dock, curly Rumex crispus
Mullein, common Verbascum thapsus
Velvetleaf Abutilon theophrasti
Dogbane, hemp Apocynum cannabinum
Nightshade, silverleaf Solanum elaeagnifolium
Table 3. Tree, Brush and Vine Species Controlled by RM43
Popular Name Scientific Name
Alder Alnus spp.
Coyote brush Baccharis consanguinea
Maple: Red* Acer rubrum
Russian Olive** Elaeagnus angustifolia
Ash Fraxinum spp.
Creeper, Virginia* Parthenocissus quinquefolia
Sugar Acer saccharum
Sage: black, white Salvia spp.
Aspen, quaking Populus tremuloides
Dewberry Rubus trivialis
Vine Acer circinatum
Sagebrush, California Artemisia californica
Balsam apple* Momordica charantia
Dogwood* Cornus spp.
Monkey Flower* Mimulus guttatus
Salmonberry Rubus spectabilis
Bearmat (Bearclover) Chamaebatia foliolosa
Elderberry Sambucus spp.
Oak: Black* Quercus velutina
Salt Cedar Tamarixs spp.
Beech Fagus grandifolia
Elm* Ulmus spp.
Northern Pin Quercus palustris
Sassafras Sassafras albidum
Birch Betula spp.
Eucalyptus Eucalyptus spp.
Post Quercus stellata
Sourwood Oxydendrum arboreum
Blackberry Rubus spp.
Gorse Ulex europaeus
Red Quercus rubra
Sweet potato, wild* Ipomoea pandurata
Blackgum Nyssa spp.
Hasardia* Haplopappus squamosus
Southern Red Quercus falcate
Sumac: Poison* Rhus vernix
Bracken Pteridium spp.
Hawthorn Crataegus spp.
White* Quercus alba
Smooth* Rhus glabra
Broom: French Cytisus monspessulanus
Hazel Corylus spp.
Persimmon* Diospyros spp.
Winged* Rhus copallina
Scotch Cytisus scoparius
Hickory* Carya spp.
Pine Pinus spp.
Sweetgum Liquidambar styraciflua
Buckwheat, California* Eriogonum fasciculatum
Holly, Florida/Brazilian Peppertree* Schinus terebinthifolius
Poison Ivy Rhus radicans
Swordfern* Polystichum munitum
Cascara* Rhamnus purshiana
Honeysuckle Lonicera spp.
Poison Oak Rhus toxicodendron
Tallowtree, Chinese Sapium sebiferum
Catsclaw* Acacia greggi
Hornbean, American* Carpinus caroliniana
Poplar, Yellow* Liriodendron tulipifera
Tan Oak Lithocarpus densiflorus
Ceanothus* Ceanothus spp.
Kudzu Pueraria lobata
Raspberry Rubus spp.
Thimbleberry Rubus parviflorus
Chamise Adenostoma fasciculatum
Locust, black* Robinia pseudoacacia
Redbud, eastern Cercis canadensis
Tobacco, tree* Nicotiana glauca
Cherry: Bitter Prunus emarginata
Madrone Arutus menziesii
Redvine* Brunnichia ovate
Trumpetcreeper* Campsis radicans
Black Prunus serotina
Manzanita Arctostaphylos spp.
Rose, multiflora Rosa multiflora
Waxmyrtle, southern* Myrica cerifera
Pin Prunus pensylvanica
Willow Salix spp.

* Partial Control

** This product is not registered in California for use on Russian olive

Related video – RM43 Update Before and After:

Where to buy RM43 Herbicide

You can buy RM43 Herbicide from various agricultural supply stores or online retailers. The RM43 Herbicide price is around $80-$100 for a bottle of 1 gallon.

Or you can buy directly from Amazon. You have the link below.

If you have any questions about RM43 herbicide that this article doesn’t answer, please don’t hesitate to ask in the comments below. I’ll do my best to answer your questions as quickly as possible.

PPE for Herbicide Application

– U.S. Environmental Protection Agency / epa.gov

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About the author: Dani Martelli
Dani FarmerDB

My name is Dani and I am a farmer with 10 years of experience. I will share with you everything about farming from processes, tips, machines, and more. Farming for me is not just a job but a way of life. Keep reading ...

    • Do you want to eliminate tomatillos, or do you want to safeguard them when using the RM43 herbicide?

      It’s important to note that RM43 is a non-selective herbicide, which means it can kill or damage a wide range of plants, including tomatillos.

      If you intend to use RM43 near tomatillo plants or in an area where tomatillos are growing, you should exercise caution and take steps to protect your tomatillo plants from potential exposure to the herbicide.

      Please explain exactly what you want to do, so I can provide you with more detailed and accurate information.

  1. I want to spray along the fence line of my horse pasture and RM43 was recommended. The label says to wait until product is complete dry before allowing pets and horses out. My question is what if my horses decided to graze along the fence line? Is their a period of time before that is safe to do or should I resort to other methods to clean up along the fence line?

    • Hi David,

      Because I really love animals, I want to share my personal opinion first. RM43 is quite a strong weed killer, and I would hesitate to use it in this situation. Even though the manufacturer suggests that you can allow animals back after the weed killer has dried, I wouldn’t do that. Also, animals should avoid grazing in the treated area even after it’s dried.

      When I use a strong weed killer, I leave it for several days to take effect, and after the plants have been affected by the weed killer, I completely remove them with a lawn mower to prevent the animals from consuming those plants. As for the time period, this herbicide has a long-lasting effect, potentially up to a year. So, unfortunately, there isn’t a specific timeframe.

      What kind of weeds should be removed? Maybe I could recommend a weed killer that is more friendly to animals.

    • Hello Clay,

      Have you been using RoundUp repeatedly on the same area? If you’ve applied it multiple times, it’s possible that the weeds have developed herbicide resistance. Therefore, RM 43 won’t be helpful for you either because it belongs to the same herbicide group (Group 9) as RoundUp and contains the same active ingredient. You need to use a herbicide from another group or consider mixing RoundUp with one of the following herbicides:

      – ArsenalTM Applicators Concentrate
      – GarlonTM 3A
      – ChopperTM
      – Garlon 4
      – EscortTM
      – OustTM
      – Escort XP
      – Oust XP
      – Outrider

      Make sure to follow the instructions carefully when using these herbicides.

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