Weeds are something we all try to avoid when it comes to our lawns. While they are technically plants, they are almost always unwanted. They steal nutrients and resources from the plants you want in your yard. They grow quickly and have an abundant amount of seeds. It does not take long for your yard to become overrun with them. There are ways to contain pesky weeds. Below is listed the best weed killer for lawns in each category.
Barricade contains the active ingredient Prodiamine and can be found in granular and liquid applications. Barricade is a pre-emergent herbicide and prevents weeds without harming beneficial and wanted plants. This is ideal when applied before weeds seeds can germinate and before weeds emerge. Barricade is one of the top pre-emergent weed killers and can be used on landscaping, ornamentals, turf, and sod farms, to name a few. It must be activated with water in 14 days or it could lose efficacy.
I use Prodiamine every April with great results and recommend it as part of my free lawn care guide.
- Lasts as long as 9 months
- Affordable and comes in generic versions
- Great weed killer of all types
- Early season application is best
- Must be watered right away
- Not the best for broadleaf weeds
- Breaks down with sunlight exposure
Best Crabgrass Killer
Drive XLR8 is one of the best post-emergent weed killers with Quinclorac as the active ingredient. It is most effective for killing crabgrass. It is good for broadleaf weeds and grassy weeds but is highly recommended for crabgrass, especially in its early stages. This is best when used on the specific weed you want to spray. Some grasses, such as St. Augustine grass can not handle quinclorac as a selective weed killer.
I have quinclorac on-hand at all times for crabgrass, and to mix with TZone for a great 4-way weed killer.
- Labeled for up to 100 different weeds
- Works almost immediately
- Does not need water to kill weeds
- Restricted in some states
- Must be cautious where it is sprayed
Best Selective Weed Killer
Speedzone is one of the best weed killers for broadleaf weeds. This post-emergent weed killer has a combination of 4 active ingredients (2,4-D, 2-ethylhexyl ester, Dicamba, Mecoprop-P). Speedzone gets into the leaf tissue and roots to provide superior and fast results. In some states, it is restricted to only those that have an application license. TZone is a great alternative for those states. Speedzone is great for homeowners as it can be purchased in smaller sizes.
We like Speedzone and Tenacity Herbicide to effectively kill all types of grassy and broadleaf weeds.
- A 4 way herbicide with 4 active ingredients
- Labeled for 100 broadleaf and grassy weeds
- Ideal for cool season turf
- Restricted in some states
Best Non-Selective Weed Killer
RoundUp QuickPro is a top weed killer for commercial and residential use. It has two active ingredients (Glyphosate and Diquat) to provide a more effective and efficient burndown. It will kill weeds such as woody brush, grass weeds, and broadleaf weeds. The rain will not wash it away due to its fast dry time. RoundUp QuickPro comes premixed with Diquat so there is no need for tank mixing.
- Contains a second ingredient
- Has a fast visual result
- Fast burndown and kills weeds to the root
- Ideal when undergoing a full lawn renovation
- May take a longer time to see results
Best Organic Weed Killer
Avenger is the best organic weed killer for lawns because it is a nonselective herbicide making it safe for the environment. It is made from orange rind with D-limonene (citrus oil) as its active ingredient. Avenger Organics removes the plant cuticle to dehydrate it so it dies. This natural weed killer is fast-acting and does not stain. However, since it is a nonselective weed killer, it will damage or kill your good grass.
I used this as part of my 2020 lawn renovation project. While I would use QuikPro next time, Avenger did the job.
- Safe for the environment
- Contains D-limonene and is organic OMRI listed
- Comes in concentrate and ready to use (RTU) form
- May not see results right away
Best Fertilizer & Weed Preventer (Step 1)
Jonathan Green Green-Up is the first step in a four-step lawn care program for a weed-free lawn. It is clear, odorless, and will not stain your hands or shoes. It contains fewer harmful ingredients than other options. It can be used all season long to effectively prevent crabgrass. It can feed lawns for as long as three months.
I’m a big fan of Jonathan Green products, and the Green-Up is the perfect pre-emergent + fertilizer combo for early spring. You can also use this and Magical Plus together.
- An excellent 4 step program
- Contains Dithiopyr (Dimension) to prevent crabgrass
- Only works up to the three leaf stage of weed growth
Best Weed & Feed (Step 2)
Scotts Turf Builder Weed & Feed is the second step of a four-step lawn weed killer program. It attacks not only weeds you can see but also ones you do not. This product should be applied in late spring for ideal results. This weed killer is ideal for dandelions, clover, and broadleaf weeds. It feeds lawns to thicken them and crowd out weeds.
I’m generally not a fan of weed and feed products, but this Scott’s product works great when applied according to the directions. It effectively kills broadleaf weeds and is the best option for those sticking to a simple 4-step plan.
- Excellent for killing dandelions
- Many satisfied customers
- Cannot be used on certain types of grass
- Grass must be wet before applying
Things to Consider
Contact Weed Killers vs. Systemic Weed Killers
Contact Weed Killers can be applied to weed stems and leaves. They work when they have contact with the weed and can be effective quickly, potentially in a few hours. It does not usually get to the root. However, by destroying the leafy green part of the plant, the root cannot survive. Annual weeds that have shallow roots are effectively killed by these weed killers.
Systemic Weed Killers soaks into leaves and travels through the plant system. These lawn weed killers stop photosynthesis to prevent nutrition absorption at the root. Systemic weed killers are best for deep-rooted perennial weeds. It may take many weeks and a second application to see results.
Selective vs. Non-Selective Weed Killers
Selective Weed Killers only kill the targeted plants while leaving surrounding grass untouched. This weed control is ideal for gardens and lawn weeds.
Non-Selective Weed Killers will kill all plants in the area. This weed killer is perfect for areas where there are no wanted plants, such as a sidewalk or driveway.
Pre Emergent vs. Post Emergent Herbicides
Pre Emergent weed killers stop weeds before they germinate and become problematic. Spring is the beginning of the weed seed germination life cycle and the best time to apply. Pre Emergent herbicides must be mixed and applied carefully. They also require watering to activate critical ingredients.
Post Emergent weed killers are applied to the leaves after the plant emerges. These are best used before the plant is mature and just as it begins to grow.
What is the Most Effective Weed Killer for Lawns?
The most effective weed killer for lawns is Southern Ag Amine 24-D Weed Killer. It can target broadleaf weeds without killing grass. This selective weed killer is a concentrated solution.
What Weed Killer Kills Most Weeds?
Ortho Weed B Gon Weed Killer kills up to 250 weeds when applied properly. This best weed killer comes in a concentrated formula that will not harm your grass. It is rainproof, ideal for southern or northern lawns, and has results in hours.
What Weed Killer Do Landscapers Use?
Glyphosate is commonly used by landscapers. It is available in many forms and is a general all purpose weed killer. There is some debate about how safe it is for humans, so be cautious when using.
When Should You Put Weed Killer on Lawn?
The best time to use weed killer is in the Spring when the plant is actively growing, closely followed by Fall. When you apply it in Spring, you catch the weeds before their pre-growth and stop them from sprouting. Spring is ideal to apply weed killer because it is warm and wet, typically conditions needed by a weed killer. Fall is also a good time because weeds are vulnerable.