Does your beautiful green lawn look like it has tiny, spiky invaders taking over? You are likely battling crabgrass. This stubborn weed pops up right when your regular grass starts looking its best, making your yard look messy. It’s frustrating to spend time and money on your lawn only to see crabgrass steal the show.
Choosing the right weed killer for crabgrass can feel like a jungle expedition. There are pre-emergent products that stop seeds from sprouting and post-emergent sprays that kill existing patches. Which one should you use? When is the best time to apply it? Making the wrong choice means wasting money or, worse, hurting your healthy grass.
This guide cuts through the confusion. We will explain the simple differences between the main types of crabgrass killers. You will learn exactly when and how to apply them for maximum success. Get ready to reclaim your lawn’s perfect look without the guesswork. Let’s dive into the best ways to defeat crabgrass for good.
Top Weed Killer For Crabgrass Recommendations
- Weed killer for lawns: Kill weeds in your lawn, including dandelion, chickweed, clover, crabgrass and foxtail with the Ortho WeedClear Lawn Weed Killer Ready-to-Spray
- Fast-acting weed control: This weed control product kills listed weeds like crabgrass, dandelion, clover, chickweed and creeping charlie down to the root and gets results with 1 application
- Broadcast treatment for weeds: Won't harm lawn grasses when used as directed - use on lawn grasses including Bermudagrass, Buffalograss, Fescues, Kentucky Bluegrass, Ryegrass and Zoysiagrass
- Spray weed killer: Apply to weeds that are young and actively growing by connecting your garden hose to the sprayer, sliding the switch to "ON" and spraying evenly until the lawn is wet
- Ready to spray: This 32 oz. container of Ortho WeedClear Lawn Weed Killer Ready-to-Spray treats up to 5,000 sq. ft.
- KILLS WEEDS – NOT THE LAWN: When used as directed
- VISIBLE RESULTS IN 5 HOURS: Conquer unruly weeds and see visible results in as fast as 5 hours
- KILLS 470+ WEED TYPES AS LISTED: Kills broadleaf and grassy weeds including dandelion, chickweed and clover as well as crabgrass and yellow nutsedge – see product label for complete list of weed types
- KILLS THE ROOT: Kills weeds by contact down to the root
- READY-TO-USE FORMULA: No mixing required
- WEED PREVENTION: Scotts Halts Crabgrass & Grassy Weed Preventer prevents the germination of listed lawn weeds so you can enjoy your lawn
- CRABGRASS PREVENTER: Prevents the germination of crabgrass, foxtail, spurge, barnyardgrass, and more as listed in the early spring all season long, and moss (except in California), Poa annua, henbit, corn speedwell, and chickweed in the fall
- APPLICATION: Apply this pre-emergent weed and crabgrass killer in the early spring to a dry lawn or in the fall; rain, snow, or freezing weather after application will not affect the performance of this lawn care product
- GRASS TYPES: This pre-emergent weed preventer is for use on all grass types (with the exception of Dichondra or Bentgrass)
- COVERAGE: One 20.12 lb. bag of Scotts Halts Crabgrass & Grassy Weed Preventer covers 10,000 sq. ft.
- Water-Based Formulation: Experience the power of our unique water-based formulation that ensures superior control and faster plant uptake, delivering results you can see quickly
- Extended Residual Control: Enjoy up to 30 days of residual control, keeping your turfgrass free from troublesome weeds for longer periods and reducing the need for frequent applications; Rainfast in less than an hour
- Broad-Spectrum Weed Control: Effectively targets a wide range of weeds, including crabgrass, foxtail, kikuyu grass, signal grass, torpedo grass, and key broadleaves like bindweed, clover, dandelion, black medic, and horseweed
- Versatile Application: Perfect for residential lawns, golf courses, commercial properties, and other non-residential turfgrass sites. It is labeled for use on both warm-season and cool-season turf types, ensuring adaptability to various environments; See label for proper mixing instructions
- USE AS INTENDED: Read, understand and follow label safety and application instructions; Follow proper storage and disposal instructions; NY can only be applied as a spot application; Proper PPE required long sleeve shirt, long pants, socks and shoes, chemical resistant gloves; See label for environmental hazards; State restrictions may apply
- ALL-IN-ONE FORMULA: BioAdvanced's All-in-One formula kills listed lawn weeds and crabgrass without harming the lawn
- KILLS TOUGH WEEDS: Control over 200 broadleaf weeds like dandelion, clover, and crabgrass using our powerful weed killer concentrate
- DOWN TO THE ROOT: BioAdvanced All-In-One Lawn Weed and Crabgrass Killer I penetrates and removes tough listed weeds down to the root
- RAINPROOF IN ONE HOUR: Our weed killer concentrate formula is rainproof in one hour, providing protection that wont wash away
- EASY-TO-USE CONCENTRATE: Easily apply with our concentrated formula, perfect for targeting weeds in your lawn, and compatible with various grass types
- KILLS WEEDS, NOT THE LAWN: Controls listed weeds – including crabgrass – not the lawn (when used as directed).
- KILLS CRABGRASS: Apply the first time you see crabgrass in your lawn.
- KILLS 470+ TYPES OF WEEDS: Controls all types of listed broadleaf and grassy weeds, including crabgrass, dandelion, chickweed, clover and yellow nutsedge (see product label for complete list).
- RAINPROOF: Rainfall or watering 3 hours after application will not wash away effectiveness.
- COVERAGE: 32 ounce bottle treats up to 5,000 square feet.
- Kill crabgrass, dandelion, clover, and other listed common weeds in your lawn with Ortho WeedClear Lawn Weed Killer Concentrate
- This fast-acting weed control kills listed weeds to the root and gets results with 1 application
- Use this lawn weed killer on grasses including Bermudagrass, Buffalograss, Fescues, Kentucky Bluegrass, Ryegrass, and Zoysiagrass
- Dilute this weed killer concentrate per label directions and apply using an Ortho Dial N Spray or tank sprayer
- This 32 fl. oz. container of Ortho WeedClear Lawn Weed Killer Concentrate treats up to 5,000 sq. ft.
Your Guide to Winning the War Against Crabgrass
Crabgrass can quickly take over a beautiful lawn. It’s an annoying, fast-growing weed. Choosing the right weed killer makes all the difference. This guide helps you pick the best product for your yard.
Key Features to Look For
When shopping for crabgrass killer, look closely at the label. Not all products work the same way.
- **Pre-emergent vs. Post-emergent:** This is the biggest choice. Pre-emergent products stop seeds from sprouting. Use these *before* you see any crabgrass. Post-emergent products kill the weeds already growing. Buy these when you see green patches.
- **Selective vs. Non-selective:** A selective killer targets only the crabgrass. It leaves your good grass alone. A non-selective killer kills everything it touches, including your lawn. Always choose selective for established lawns.
- **Longevity:** Some products offer protection for several months. Others only last a few weeks. Longer protection means fewer applications later in the season.
- **Safety Rating:** Check if the product is safe for pets and children after it dries. Some require a waiting period before re-entry to the lawn.
Important Materials Inside the Bottle
The active ingredients decide how well the product works.
For pre-emergent control, you will often see ingredients like **Pendimethalin** or **Prodiamine**. These form a barrier in the soil. For post-emergent control, look for **Quinclorac**. This chemical is very effective at killing crabgrass without harming most common lawn grasses like Kentucky Bluegrass or Fescue.
Also, check the carrier material. Is it a liquid concentrate that you mix with water? Or is it a granular product that you spread with a spreader? Granular products often cover larger areas easily. Liquids can sometimes penetrate the soil better.
Factors That Improve or Reduce Quality
The quality of your weed killer is tied to timing and formulation.
Timing is everything. Applying a pre-emergent too early or too late greatly reduces its effectiveness. Soil temperature is key. Most experts say apply when soil hits 55 degrees Fahrenheit for several days straight. If you use a post-emergent product when temperatures are very high (over 90°F), the grass might get stressed. This can cause the weed killer to burn your good lawn, reducing quality.
Products that are highly concentrated often offer better value and strength, improving overall quality. Low-quality products might require multiple, heavy applications to see results.
User Experience and Use Cases
How easy is the product to use? This impacts the whole experience.
For small areas, a ready-to-use spray bottle is simple. You just attach it to a hose and spray. For large yards, a hose-end sprayer or a broadcast spreader for granular products saves a lot of time. Read reviews about how the product mixes. Some concentrates clump up, making application frustrating.
Use cases vary. If you have a new lawn, you must use a product labeled safe for new grass seedlings. If you have thick weeds already, a strong post-emergent is necessary. Always follow the mixing instructions exactly. Over-application is wasteful and can harm your lawn.
Frequently Asked Questions (FAQ) About Crabgrass Killer
Q: When is the best time to apply pre-emergent crabgrass killer?
A: Apply it in early spring, before the crabgrass seeds germinate. Watch the weather; soil temperature around 55°F for a few days is the signal.
Q: Can I use crabgrass killer if I just seeded my lawn?
A: No, most pre-emergents will stop your desirable grass seeds from sprouting too! Wait until your new lawn is established, usually after three to four mowings, before using pre-emergents.
Q: How long until I can let my dog walk on the lawn after spraying?
A: Check the product label. Usually, you must wait until the treated area is completely dry. This could be a few hours or up to a full day.
Q: Will one application of post-emergent killer get rid of all the crabgrass?
A: Maybe not. If the crabgrass is very thick or mature, you might need a second application two to three weeks later, depending on the product instructions.
Q: What is the main difference between liquid and granular crabgrass killer?
A: Granular products are spread dry and rely on rainfall or watering to activate them. Liquids are mixed with water and sprayed directly onto the weed for immediate contact.
Q: Does crabgrass killer harm clover or violets in my lawn?
A: Selective post-emergent killers designed for crabgrass often control other broadleaf weeds like clover too. Always check the label to see which weeds are targeted.
Q: Can I use a weed killer if it is raining or about to rain?
A: Avoid spraying right before heavy rain. The rain will wash the product away before it can work. A light sprinkle is usually fine for activating granular products.
Q: Why is my crabgrass turning brown but not dying completely?
A: This often means the product is slowing the growth but not killing the root system. Ensure you used the correct amount and that the product is rated for deep root kill.
Q: Are organic options available for crabgrass control?
A: Yes, some organic options use corn gluten meal as a natural pre-emergent. These are gentler but usually require heavier, more frequent application than chemical options.
Q: What should I do if I accidentally spray my flower beds?
A: If you used a selective killer, the flowers are probably safe if they are not grasses. If you used a non-selective killer, immediately flush the area heavily with water to dilute the chemical, though severe damage is likely.