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Spectracide vs Roundup: Picking Up the Best Weed Killer



by Bryan Mckenzie


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Home » Lawn care » Spectracide vs Roundup: Picking Up the Best Weed Killer
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If you are confused about which herbicide to choose, you are not the only one. Among all of this diversity, two herbicides are the most noticeable. Roundup and Spectracide are believed to be the most effective and affordable options for gardeners. But don’t rush with the decision as the battle of Spectracide weed and grass killer vs Roundup is still something that stays unsolved for years.

The main difference between Spectracide and Roundup is that the former can eliminate only the upper part of the weed. The latter kills not only the upper part but the entire root system. However, Spectracide is considered safer as it doesn’t persist in soil and water as long as Roundup.

They both are trusted and checked a thousand times. I decided to compare Spectracide vs Roundup to help you make a choice. You can check out all my recommendations, and decide which item is the most suitable for you.

Spectracide and Roundup Major Features

There are two products on my list. I am going to extend the information about their features. If you have used one or both of them before, you can share your impressions in the comments.

Spectracide Weed & Grass Killer – Detailed Guide on Features from Spectracide Weed and Grass Killer Reviews

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Spectracide is offered in a convenient pack with an attached sprayer. It becomes rainproof in 15 minutes. How long does Spectracide take to work? It offers you results after the first 3 hours. It is already mixed and ready to use, so please, under no circumstances don’t try to add anything else inside. I don’t recommend you to open the bottle without any specific reasons and urgent need.


  • Dimensions 4.5 x 7.5 x 12 inches;
  • Attached sprayer;
  • Weighs 8.38 pounds;
  • Active ingredient: diquat dibromide.

This is a 1-gallon pack, which is savvy, considering that you don’t need to spray it several times, and one will be enough. However, as I’ve warned you before, you need to spray the whole weed, from the leaves to the stem. It is recommended for walkways, patios, driveways. The sprayer is comfortable to use, and you can separate weeds from flowers and shrubs. If you want to protect some plants for sure, you can cover them with plastic or cardboard during the applying process. The sprayed leaves will get yellow, brown; then, they will curl, twist, and dry out. Avoid contact with the chemicals inside the pack. Keep the pack far from children and pets.

  • Affordable price;
  • Visible results in 3 hours;
  • Savvy 1 gallon pack;
  • Easy to apply;
  • Resistible to rain in 15 minutes.
  • Contains dangerous chemicals.

Roundup Weed & Grass Killer Concentrate – What Works Better Than Roundup on Big Areas?

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Roundup kills even the oldest and the biggest weeds. There is a consumer guarantee for this product, but it is hardly needed, as Roundup is one of the most powerful weed killers nowadays. You have to be careful, as it kills every plant it is sprayed onto. There is no tank sprayer in the pack, so you have either use the old one or buy new additionally. Do not use it close to the veggies or fruits.


  • Dimensions of the bottle: 2.37 x 3.69 x 7.13 inches;
  • It weighs 1.28 pounds;
  • The active ingredient is glyphosate;
  • There is a measuring cup for comfortable use.

In 30 minutes, this herbicide becomes rainproof. In 12 hours, you can see visible results of its action. You can plant something new several days after the application. This product can be mixed with water, depending on your needs. Read the instruction on the bottle. There is also a measuring cup for your convenience. The developers recommend using 6 fl oz for 1 gallon of water. I specifically warn you about the need to use protective gloves and glasses even during the mix of water and Roundup in the tank sprayer. Remember how easily this chemical kills every weed and plant around. Keep it far from children or animals.

  • Powerful action;
  • Measuring cup;
  • Savvy offer;
  • Rainproof in 30 minutes;
  • Acts in 12 hours.
  • You need to keep it far from other people or animals.

Spectracide vs Roundup: Everything You Wanted to Know

I have to start by underscoring the fact that these products are herbicides. They both were made to kill the weed in your garden. Each of them has its advantages and disadvantages, but they all are the most trusted when it comes to grass killing.

The Difference Between the Products

The most obvious difference is their ingredients:

  • Spectracide active ingredient is diquat. The product has 2.30 percent of diquat dibromide, which dries the plant. This ingredient works only on the sprayed place. If you did not spray Spectracide on the weed, it would not die even if you sprayed all its neighbors.
    Diquat does not spread into the water and soil or the plants it did not contact physically. Diquat is mainly used to kill potato vines, seed crops, and take under control the sugar cane’s flowering;
  • Roundup contains 18 percent of glyphosate and 0.73 percent of diquat. Glyphosate blocks PEP or Phosphoenolpyruvate molecule in the plant. This molecule is crucial for the metabolism process not only for plants but for animals as well.
    Unlike Spectracide that kills only the part that it touches physically, glyphosate quickly moves inside the plant, killing it up to the core. Gardeners use it to kill old weeds with widely spread roots. It works perfectly on sedges, weedy grasses, dandelions, and even woody plants. It is used on crops and non-crops.

Many gardeners wonder, does Spectracide contain glyphosate? While Roundup contains diquat, Spectracide does not contain glyphosate. It has numerous minor ingredients, but its main component is still diquat dibromide.



Both herbicides kill plants for good, no matter whether it is a weed or the plant you were taking care of. So, be careful when spraying them in your yard. Spectracide is a top choice when it comes to the weeds that grow close to your crops. It does not kill plants that it did not get in touch with. Roundup can quickly move on big territories, spread from one plant to another. Roundup is a lifesaver for gardeners who have old weeds they can’t get rid of.

To kill the weeds in your garden with Spectracide, you have to apply it to every plant you need. To kill weeds with Roundup, all you need is to spray it around the territory you want to clear. You might be required to repeat the procedure with Spectracide if it did not kill everything you wanted.

Application Specifics

Both Spectracide and Roundup are liquids. They both must be applied to the areas of plants you want to get rid of. Spectracide starts acting as soon as it is applied onto the weed. However, Spectracide can be applied to the weeds that grow close to the crops. All you need to do is move carefully, and probably take the thinnest nozzle for applying the spray. And if you applied it accidentally on the plant you want to save, wash it quickly off with ordinary water.

Roundup is also sprayed. It immediately travels through leaves and stems to the roots. Don’t apply it when the wind is strong, as it will spread around everywhere.


roundup weed killer

Many beginners are asking: is Spectracide weed killer safe based on the assumption that while it acts on specific zones it covers, this herbicide is safe. The truth is both of them contain harmful chemicals and are not safe. You have to protect your face and body while spraying these herbicides, no matter which one you choose. Glyphosate in Roundup has a long history of restrictions. This chemical kills every plant and is widely used in the most problematic areas. However, some states ban it from use due to the suspicion that it may be carcinogenic to humans.

The amount of this component in Roundup is not big enough to cause concerns; however, you must apply this product carefully, wearing masks and gloves. Do not keep it in places reachable for children. Comparing Spectracide vs Roundup safety many users believe that Spectracide is safer. With the amount of glyphosate in Roundup and diquat in Spectracide, they are equal. Diquat attacks roots and weeds as well after it gets inside the plant. In the significant amounts, diquat dibromide is highly dangerous absorbed through the skin or inhaled. It can be fatal.

So, if you still wonder is Spectracide safer than Roundup, you don’t want to choose among cancer caused glyphosate dangers and suffocating diquat. Luckily for you, the standard packs of Roundup and Spectracide contain a small amount of these chemicals.


I have heard multiple questions about these two products. Many gardeners are curious about specific features of Roundup and Spectracide. This is why I gathered all these questions here.

Is Spectracide the same as Roundup?

No, these are two different herbicides. They contain different chemicals and have various features. They both are weed killers that are widely used in the country. They also act incredibly quickly and effectively.

What is a good alternative to Roundup?

I recommend you to use Spectracide as a good alternative to Roundup. They are equally powerful when it comes to weed killing. They both can be used near fences, other plants, in the yard, on the sideways. However, unlike Roundup, Spectracide does not contain glyphosate. Some gardeners who prefer to use natural weed killers recommend a mix of salt and vinegar instead of Roundup, but I don’t find them similarly effective.

What weeds does Spectracide kill?

Spectracide kills multiple types of weed. It is perfect for areas with mixed types of plants, as you can specifically spray only weeds you want to kill. It works splendidly with the broadleaf weeds like clover, dandelion, chickweed. It also kills zoysia, bluegrass, ryegrass, Bermuda, fescue. It is great with small and fresh weeds.

Is Spectracide safe for pets?

No! Both Spectracide and Roundup are dangerous for pets. You have to make sure that your pets will not approach the sprayed weeds at least during the first hours. Make sure that your pets will not receive access to Spectracide concentrate from the battle. You have to put it in a place unreachable for others. There are chemicals in this product that may be fatal for pets.

Does Roundup lose potency over time?

After being sprayed, Roundup does not lose its potency for over 47 days, depending on the type of soil and the layer of the herbicide that was applied. It is not active on the soil unless it gets to the weed. To act is has to reach the plant. After the Roundup is mixed with the water, you can leave it in the tank for several weeks. Some gardeners say that they are using the same mix they’ve made 2 years ago, but I recommend you mix a small amount of herbicide and apply it during the next few days.

How long does it take for Spectracide to dry?

In 15 minutes minimum after you applied Spectracide, it will dry and be irresistible to the rain. I recommend you to wait for 30 minutes to make sure that it is dried. After that time, it can be sprayed with water. I don’t recommend you touch leaves of the sprayed plants earlier than in a few days, just to make sure that they are not toxic.

Is Spectracide safer than Roundup?

Unfortunately, this is a common thought spread around our country. Even experienced gardeners sometimes believe that it is ok to touch plants sprayed by Spectracide right after they were sprayed mainly because its active ingredient is diquat dibromide. However, it is not true. Chemicals in both herbicides are dangerous, and you can’t touch them with bare hands.

Does Spectracide contain Glyphosate?

While Roundup contains both glyphosate and diquat dibromide, Spectracide does not contain glyphosate. It does not mean that Spectracide is safer because of it. Diquat is banned in many states and the EU in big doses.

Which Herbicide to Pick?

I recommend you to buy both herbicides. They are affordable and stay active for a long time. You are going to need them in your garden and yard at least once in a time. There are multiple advantages and several disadvantages to these herbicides. Personally, I suggest you use Spectracide in case you have weeds grown inside the flowers, and you don’t want to kill everything. It is great with small and young weeds as well.

For old weeds and big territories, I recommend using Roundup. You have to be careful with both products as they are toxic. Have you tried them before? Please write in the comments whether you like them or not and why.

Bryan Mckenzie
Hi there — my name is Bryan McKenzie. Before I’d got into gardening, I worked as a landscape designer at landscape design and consultation company in Jacksonville. I enjoy sharing the vast gardening experience I’ve accumulated throughout the years with like-minded green thumbs. Read more about me and my wife.
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