Ortho Killex vs Roundup Weed Killer

The main difference between Ortho Killex and Roundup Weed & Grass Killer is that Ortho Killex is a selective herbicide, while Roundup is a non-selective herbicide.

Ortho Killex will target and kill specific weeds without harming lawn grasses. Roundup will kill all vegetation that it comes into contact with, including lawn grasses.


Killex Vs Roundup Table

This comparison table will provide you with a quick understanding of the differences.



Active Ingredients of Ortho Killex is 2,4-D, Mecoprop-P, and Dicamba

Active Ingredients of Roundup Weed & Grass Killer is Glyphosate and Diquat

Wipe Out Lawn Weeds Effectively!

You Get Visible Results In 3 Hours

Effective Weed Control For Lawns & Won’t Harm Grass

Kills Weeds To The Root So They Wont Come Back

Mix Ortho Killex of 6 ml per gallon of water to treat 50 square feet

Mix 3.2 oz per gallon of water which can treat up to 160 sq. ft

Simply Mix The Concentrate With Water And Apply With A Hand-held Tank 

It Works By Targeting An Enzyme That Is Essential To Plant Growth 

Safe For Pets And Children After It Dried

People & Pets Safe After Spray Has Dried

Ortho Killex is a selective herbicide, meaning it will only kill the weeds that you target.

It's a non-selective herbicide, which means it will kill any plant with which it comes in contact

Avoid Watering For 24 Hours After Applying

Economical To Treat Large Areas (Rainproof in 30 minutes)

It Controls Over 50 Different Lawn Weeds, Including Dandelions, Ground Ivy And Ragweed

Kill Any Type of Toughest Weeds And Grasses Down To The Root


Ortho Killex Lawn Weed Killer Concentrate works by altering plant cell growth in weeds, leading to death. It contains three active ingredients – 2,4-D, Mecoprop-P, and Dicamba.

Roundup Super Concentrate Weed & Grass Killer is absorbed by the weed’s leaves and starts working on contact. It kills weeds down to the roots so they won’t regrow.

Active Ingredient

The active ingredients in Ortho Killex are 2,4-D, Mecoprop-P, and Dicamba. This combination of ingredients allows Ortho Killex to target broadleaf weeds without harming lawn grasses when used as directed.

Roundup contains Glyphosate isopropylamine salt as its active ingredient. Glyphosate is a broad-spectrum systemic herbicide that kills any vegetation it comes into contact with by disrupting plant growth processes.

What It Kills

Ortho Killex effectively kills over 50 types of broadleaf weeds like dandelions, creeping Charlie, plantain, and clover without damaging lawn grasses.

Roundup Super Concentrate kills over 200 types of weeds and grasses, including tough weeds like Ground Ivy, Canada Thistle, Johnsongrass, Mugwort, Nutsedge, Poison Ivy, and Field Bindweed. It can be used to kill any type of unwanted vegetation.

Not Effective

There are certain weeds and grasses that Ortho Killex does not effectively control, including sedges, palms, buttercups, bindweed, creeping bellflower, and bentgrass.

Since Roundup is a broad-spectrum herbicide, there are very few weeds or grasses that it will not effectively kill.

Mixing Ratio

For the best results with Ortho Killex, the mixing recommendation is 6 mL per liter of water to treat 5 square meters.

For Roundup Super Concentrate, mix 2.5 fl. oz. with 1 gallon of water for optimal weed control. Carefully follow the label instructions for mixing ratios when using either product.

Where to Use

Ortho Killex can be used on lawns, patios, walkways, driveways, gravel areas, mulch beds, and along fences and foundations.

Roundup Super Concentrate can also be used in all of these areas, plus around flowers, shrubs, and trees, and for larger applications like lawn renovation or garden plot preparation.

Tank Sprayer

Both Ortho Killex and Roundup Super Concentrate can be effectively applied using a tank sprayer like the Scotts Dial N Spray Hose-End Sprayer. This allows you to mix up the right amount of product and precisely spray weeds.

Spot Treatment

A benefit of using Ortho Killex is that it can be used for spot treatment of weeds in lawns without harming the surrounding grass.

Roundup is not recommended for weed spot treatment in lawns because it will kill the lawn grasses and weeds.


Ortho Killex becomes rainfast within 6 hours after application. Roundup Super Concentrate becomes rainproof faster within 30 minutes of application. This means rain will maintain the effectiveness of both products.

Visual Results

Ortho Killex will show visible weed control results within two days, but it may take up to 2 weeks for complete control. Roundup works extremely quickly, delivering visible results within 2-4 days after application.

When to Apply

For best results, apply Ortho Killex when weeds are young and actively growing. Roundup works best when weeds are actively growing and during warm, sunny weather above 60°F.

Where Not to Use

Avoid applying Ortho Killex directly on flowers, shrubs, vegetables, and fruit crops. Roundup should not be allowed to contact desirable plants until the spray has thoroughly dried to prevent damage.

How Often to Apply

Some tough weeds may require a repeat application of Ortho Killex in 3-4 weeks. For Roundup, some established weeds may need a repeat application, and regrowth should be resprayed in spring if occurring after a fall application.

Our Observation
Roundup Super Concentrate appears to be the stronger and faster-acting weed killer overall. It controls an extensive range of weeds and grasses, works faster, and requires less reapplication than Ortho Killex.

However, for selective weed control in lawns, Ortho Killex is the better choice since it won’t harm lawn grasses when used properly. For non-lawn areas and larger-scale vegetation control, Roundup Super Concentrate is likely the more practical option.

Ultimately, choosing between these two quality herbicides depends on your specific vegetation management needs and application area. We recommend Roundup for non-selective weed control and Ortho Killex when selectively targeting lawn weeds.

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