Glyphosate Vs Diquat (Compared)

Weeds are stubborn little things. 

You pull them, they come back. You mow them, they pop right up again. 

That’s where herbicides come in, and two of the big names you’ll see on shelves are glyphosate and diquat. They might look like they do the same job, but the way they work is totally different. 

If you’ve been trying to figure out which one makes the most sense for your yard, garden, or project, this Glyphosate vs Diquat comparison will clear things up.

#1. How Does It Work?

Let’s start with the basics, how these two actually do their job.

Glyphosate is a systemic herbicide. This means when you spray it on a plant, the plant absorbs it through the leaves. The herbicide then travels throughout the plant and disrupts an enzyme that’s necessary for the plant’s growth. 

This process slowly kills the plant from the inside out. 

Because of this, glyphosate is effective on almost any type of plant.

Diquat is a contact herbicide. It doesn’t travel through the plant like glyphosate does. Instead, it causes damage to the plant’s outer layers right where it’s sprayed. 

Diquat acts fast and is powerful, but it doesn’t penetrate as deeply as glyphosate.

So right out of the gate, the way these two products attack weeds is totally different. Glyphosate goes for the whole plant. Diquat just scorches the top.

#2. Speed of Action

Diquat works a lot faster than Glyphosate. 

It works quickly (sometimes within hours) causing visible damage to the plant within a short amount of time. If you want to see results almost immediately, this is your best bet. 

It’s often used when you need to take out plants quickly, like in commercial settings or for fast weed control in gardens or lawns.

Glyphosate takes a bit longer. It can take anywhere from 1-2 weeks to fully kill the plant. 

This slower action might seem like a downside, but it’s actually a good thing in some cases. Since it works systemically, the plant needs to fully absorb it and start shutting down before you see the results. This takes time. 

But, because it kills the plant from root to tip, you’re more likely to see lasting results.

#3. Effectiveness On Roots And Regrowth

Glyphosate is the clear winner here. 

Since it’s systemic, it gets into the roots and destroys the entire plant. This means the chance of regrowth is significantly lower. 

If you’re dealing with perennials or plants that you want to make sure don’t come back next season, glyphosate is usually the safer bet. It can take out even the toughest roots!

Diquat doesn’t affect the roots. It only targets the parts of the plant it comes in contact with. 

If you’ve got weeds that regenerate from their roots, like many grasses or perennials, diquat might just cause a temporary burn, but the plant will likely bounce back in no time. 

So, it’s not as effective at long-term control, especially for plants that have strong root systems.

Also Read: The Dangers of Root Intrusion

#4. How Long Do the Results Last?

Glyphosate’s effects tend to last longer because it destroys the entire plant, including its roots. 

You might not see new growth for a while. 

But, keep in mind, if you don’t manage the soil or have a lot of new seeds floating around, new weeds could eventually pop up. So, while glyphosate gives long-lasting results, it doesn’t guarantee that the area won’t eventually see new growth.

Diquat works fast but doesn’t last as long. 

Since it only affects the top part of the plant, new growth can happen fairly quickly. It’s only good for short-term solutions or for quickly cleaning up a garden or lawn before you replant something else.

#5. Prices

Prices can vary depending on brand and size, but here’s the general picture:

• Glyphosate usually runs around $20 – $40 per gallon for concentrate. One gallon can cover a large area since it’s mixed with water.
  
• Diquat usually costs $15 – $30 per quart, but it doesn’t go as far since you’ll need to reapply more often.

At first glance, diquat may seem like the cheaper option. But when you factor in repeated treatments, glyphosate often ends up being more cost-effective in the long run.

Plus, glyphosate is usually more affordable per gallon, especially in larger quantities. 

Also Read: Will 2,4-D  kill trees?

#6. Common Uses

Now, what are these herbicides best for?

Glyphosate is extremely versatile. It’s used for everything from lawn care to agricultural fields. You’ll find it in places where you need to kill broadleaf weeds, grasses, or even brush. 

If you’re looking to clear a large area for construction or landscaping, glyphosate is commonly used because it can handle tough, woody plants and grasses. It’s also commonly used in home gardens to control weeds in flower beds and vegetable patches.

Diquat is often used for specific tasks like controlling aquatic weeds in ponds or lakes. 

It’s great for spots that need a quick and efficient kill, like clearing out weeds in water bodies. 

Diquat is also sometimes used in non-crop areas like parking lots or driveways, particularly when you need fast results.

#7. What About Safety and the Environment?

Both glyphosate and diquat come with their share of controversy and safety rules.

Glyphosate has been in the news a lot because of health concerns tied to long-term exposure. 

While the EPA in the U.S. still allows it, there are debates about its safety for humans and animals. It also lingers on plants until it breaks down, though it doesn’t usually stick around in soil for long.

Diquat, while not as widely discussed in the media, has its own issues. It’s very toxic to aquatic life, which is ironic since it’s often used in water. 

That’s why the application has to be carefully controlled. 

It’s also dangerous if swallowed or if it comes into contact with skin in large amounts.

Both chemicals require responsible use and safety gear, but if you’re aiming for something that’s safer around water or more controlled areas, diquat might be the better option.

Also Read: Do Pine Needles Kill Grass?

Should I Get Diquat Or Glyphosate?

So, which one should you choose? It really comes down to your specific needs.

If you need a reliable, long-term solution to wipe out weeds and don’t mind waiting a little for results, glyphosate is probably your best bet. 

It’s the more versatile option, especially for tougher, woody plants.

But if you need something that works fast and doesn’t mind reapplying, diquat could be the way to go. It’s great for spot treatments or places where you want immediate effects.

Both have their pros and cons, but once you know what you need like speed, lasting results, or effectiveness on roots, you’ll have a better idea of which one to grab off the shelf!

Bottom Line

The main difference between glyphosate and diquat is that glyphosate works slower but kills the entire plant, roots and all, making it better for long-term weed control. Diquat, on the other hand, works super fast but only burns down the top growth, so plants often regrow. 

Glyphosate is usually more cost-effective over time, while diquat is best when you need quick results, aquatic weed control, or temporary cleanup.