Crossbow vs Roundup: [Top Weed Killer Comparison]

If you want to kill vines, ivy, brush, and brambles, Crossbow is the best choice. It’s a selective herbicide designed to wipe out woody plants and weeds without harming the grass. Use Roundup to wipe out pest grasses and lawn weeds. Roundup is a non-selective herbicide that kills all weeds and grass, but isn’t as effective as Crossbow at clearing brush and ivy.

Crossbow vs Roundup

What’s the Difference Between Crossbow and Roundup?

Crossbow is a selective herbicide that will kill weeds and woody plants without harming grass and grassy weeds. Roundup is a non-selective herbicide that will harm every plant it is exposed to, including grassy weeds like crabgrass and nutsedge, as well as the grass in your yard.

  • Crossbow is a selective herbicide that attacks weeds, ivy, and leafy plants, but will not harm grass.
  • Roundup is a non-selective herbicide that will attack all plants whose leaves are sprayed with the compound.
  • Both Crossbow and Roundup are post-emergent herbicides, meaning they only attack weeds that are visible. They won’t stop new weeds from sprouting.
  • Crossbow contains the active ingredients Triclopyr and 2,4-D, which allow it to kill tough woody plants and common weeds.
  • Roundup contains Glyphosate as an active ingredient, which allows it to attack all plant types, but it is not particularly effective against woody plants like Triclopyr.

Because of their very different formulations, Crossbow and Roundup are best when applied to different problems. Both can be useful tools in your lawn care arsenal when applied correctly.

Which is Better: Crossbow or Roundup?

Both Crossbow and Roundup have strengths and weaknesses. Crossbow won’t kill crabgrass but Roundup will. On the other hand, poison ivy will shrug off an application of Roundup, while Crossbow will wipe out the ivy.

In this article, we will be comparing the following products:

  • Crossbow: Concentrate containing 34.4% 2,4-D and 16.5% Triclopyr.
  • Roundup III: Ready to use with 2% Glyphosate.

We’ll point out the strengths and weaknesses of both products, so you can make the right choice to wipe out weeds without a problem.

What is the Best Use for Crossbow?

Crossbow is most effective at killing woody plants, such as ivy, vines, brambles, and brush. It is commonly used along fencerows and drainage areas to clear out tough overgrowth. It’s great for fields and lawns because it does not harm grass.

  • Killing poison ivy, brambles, tough brush, and thorny vines.
  • Often applied to fencerows and overgrown areas.
  • Will not harm grass, including both lawn grass and grassy weeds.
  • Attacks common broadleaf weeds, including clover, dandelion, and chickweed.
  • Will kill garden plants exposed to the herbicide.

Because of the inclusion of 2,4-D in Crossbow, it is effective at killing the most common annual and perennial broadleaf weeds you will find in your lawn and garden. Because Crossbow is mostly intended as a brush killer, using it to wipe out lawn weeds is a little like using a flamethrower to light a candle. Be careful when applying Crossbow, as it can kill garden plants.

Tough Brush and Weed Killer
Southern Ag | Crossbow Weed & Brush Killer | 2,4-D and Triclopyr
  • Size: 1 Quart.
  • Contains 2-4, D and Triclopyr for control on most unwanted trees and brush.
  • You can use this on non-crop and non-timber areas.
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What is the Best Use for Roundup?

Roundup is a broad-spectrum weed and grass killer. It is best used for clearing entire areas of all grass and standard types of weeds. It is great for killing weeds growing in concrete seams and cracks between pavers.

  • Killing turf grass, grassy weeds, and common weeds in overgrown lawns.
  • Spot-treatment of weeds and grass in concrete, gravel, and paved areas.
  • Will harm both lawn grass and grassy weeds.
  • Is not as effective as Crossbow at killing woody plants like ivy, brush, and brambles.

Although Roundup is a very versatile product, it is not ideal for killing vines and brush. Attempting to do so can take several applications and tough plants may still come back. For attacking tough, woody plants Crossbow is a great alternative to Roundup.

Visible Results in 3 Hours
Roundup Ready-to-Use Weed & Grass Killer III | Kills Toughest Weeds | No-Mix Formula | Visible Results in 3 Hours
  • Kills the toughest invasive grass and weeds down to the root.
  • No-mix formula that is convenient and easy to use.
  • Rainproof in 10 minutes with visible results within 3 hours.
We earn a commission if you click this link and make a purchase at no additional cost to you.

Will Crossbow Kill Dormant Weeds More Effectively than Roundup?

Crossbow has proven that it can successfully attack dormant weeds, including vines, brush, and brambles, even during fall and winter dormancy. Roundup, on the other hand, does not attack dormant plants and grasses.

  • Crossbow can kill dormant weeds. It is effective when applied to weeds in fall and winter.
  • Roundup is ineffective against dormant plants. It won’t attack undesirable plants during fall and winter.

The reason Crossbow can attack dormant plants is that the Triclopyr and 2,4-D in the herbicide infiltrate plants through leaves, bark, and roots, even when the plant isn’t actively growing. Glyphosate, the active ingredient in Roundup, must be absorbed through leaves actively undergoing photosynthesis, so it is ineffective in fall and winter applications.

Will Crossbow Kill Weeds Faster than Roundup?

Crossbow and Roundup both kill weeds in the same amount of time. Crossbow takes 7-14 days to kill weeds. Roundup requires 7–14 days to kill plants and grasses down to the root. While both herbicides require time to work through the plant’s system to kill it completely, Crossbow can be a faster-acting alternative to Roundup.

  • Crossbow kills plants in 7-14 days.
  • Roundup kills plants in 7–14 days.
  • Both products work fastest on young plants. Mature weeds and brush may require multiple applications.

Although Crossbow is typically more powerful than Roundup, it is most effective in spring or when sprayed on young weeds. If a plant survives the initial application, perform a second application 14 days after the first.

How Long Does Crossbow Have to be on Before Rain vs Roundup?

Crossbow requires 6 hours of drying time before it is rainfast. Roundup is rainfast in 30 minutes. Although Crossbow does require more time before it can withstand the elements, if you apply on a dry day, there should be no danger.

  • Crossbow is rainfast in 6 hours.
  • Roundup is rainfast in 30 minutes.

Check the forecast before applying Crossbow. When working with a strong brush killer, choose a dry, wind-free day so you can safely direct the spray on the plants you want to kill.

Roundup and Crossbow Herbicide Dangers

Roundup is much safer for nearby plants than Crossbow. Roundup is only harmful when absorbed through the leaves and becomes inert in soil. So, plants will not be harmed by water runoff from Roundup. Crossbow, however, stays active in the soil for up to 6 weeks. Precipitation and watering may cause Crossbow to “drift” in the soil, attacking plants outside the original area of application.

  • Roundup is inert in soil and won’t attack plants that were not directly sprayed with the herbicide.
  • Crossbow is active in the soil for up to 6 weeks. Runoff may cause it to drift and attack nearby plants.
  • The active ingredients in Crossbow and Roundup have been classified as safe by the EPA.
  • Despite the classification, both Triclopyr (Crossbow) and Glyphosate (Roundup) have been linked to increased cancer risk by independent studies.

The EPA has classified Triclopyr, one of the ingredients in Crossbow, as a Class D chemical and deems it “not classifiable as a human carcinogen.” Glyphosate, an active ingredient in Roundup, is also considered non-carcinogenic to humans by the EPA. However, outside sources have brought controversy to both these claims. Safe alternatives to these chemicals include naturally derived herbicides, such as Ammonium Nonanoate.

Which Weed Killer is Better: Crossbow or Roundup?

When choosing between Roundup and Crossbow, assess your need. If you need to kill tough brush, ivy, and brambles without harming the grass, Crossbow has the superior strength for the job. If you want to kill invasive grass and common weeds, Roundup is the better product. Remember, Crossbow won’t kill grass and grassy weeds but Roundup will. Which one you choose depends on the plants you’re trying to eliminate.

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