The Best Weed Killers for the Lawn and Garden
Control dandelion, crabgrass, and other unwelcome garden guests with the right weed killer for your needs. Ahead, learn about the different types of weed killers and how to choose between them—and don't miss our roundup of top-favorite picks!
Whether they crop up on your lawn, in a flower bed, or along the perimeter of a fence, weeds are the gardener’s age-old enemy. They make your yard unsightly, your walkway unkempt, and they compete with neighboring plants for sunlight, water, and nutrients, causing your cherished plants to weaken and be susceptible to pests and disease. Weed species can even spread and disrupt natural habitats. Worst of all, weeds just seem to keep coming back no matter what you do.
Fortunately, there are a few options for weeding these invaders out for good: deadheading weeds with garden shears or a weed wacker (cutting off the tops), removing them from the soil by hand, or using weed killers. Of these methods, deadheading is generally useful only for annual plants that don’t have extensive root systems and that die when the tops are separated from the roots. Pulling weeds by hand, meanwhile, is impractical if you have large number of weeds due to the effort involved (not least because doing so effectively requires digging up the roots to keep them from growing back). The limits of these manual methods make commercial weed killers the more fail-safe, flexible option for eradicating weeds—provided you choose the right one for the job.
Read on to learn what to look for in a weed killer and why the below are our top-favorite picks among the best weed killer options available:
- BEST PRE-EMERGENT WEED KILLER: The Andersons Pro Turf Barricade Granular Pre-Emergent Weed Control
- BEST POST-EMERGENT WEED KILLER: Green Gobbler Vinegar Weed & Grass Killer
- BEST SELECTIVE WEED KILLER: Southern Ag Amine 24-D Weed Killer
- BEST CONTACT WEED KILLER: Spectracide Weed & Grass Killer Concentrate
- BEST SYSTEMIC WEED KILLER: Ortho Nutsedge Killer for Lawns
Key Considerations for Choosing a Weed Killer
The type of weed killer you choose will dictate where you apply it, at which growth stage to apply it, which types of weeds it will kill, how it will impact plants nearby, and how long it will control weeds. This means that even a well-reviewed weed killer that’s not designed to solve your specific weed problem can result in product failures, and, hence, lingering weeds. To maximize product performance and minimize the risk of herbicide failure, factor in the following properties when choosing the right commercial weed killer for the job.
Emergence refers to the stage of weed growth at which you must apply the weed killer.
- Pre-emergent weed killers, sometimes labeled as “weed preventers,” target and kill the germinating (sprouting) seedlings of weeds before they emerge from the soil as weeds you can see. You generally apply them to the soil of lawns or gardens before you see signs of weeds; they will form a chemical barrier in the top layer of soil that will stop the growth of seedlings underground, in effect killing them.
- Post-emergent weed killers, also known as herbicides, are used to control existing weeds that have already emerged from the soil. Apply them to the leaves and/or stems of visible weeds in garden beds or driveway or sidewalk cracks; the chemicals will kill the weeds either by destroying the foliage or stems or traveling down to the roots and killing the whole root system.
Selectivity is the ability of a weed killer to destroy weeds but leave surrounding plants unharmed.
- Selective weed killers destroy weeds but not turfgrass or other beneficial plants in the vicinity, making them a good option for eradicating, for example, dandelions or thistles on the lawn or in a flower bed.
- Non-selective weed killers eradicate weeds along with any other plants in the application area. Use them along the fence or pool or in driveway or sidewalk cracks, where you won’t put beneficial plants at risk.
Translocation describes the movement of the product within a weed once it is taken up through the leaves, stems, or roots of the plant.
- Contact weed killers don’t move within a weed after they enter it; rather, they kill the weed by destroying the plant part to which you apply them, usually within hours to days of application. They’re commonly used on annual weeds, such as crabgrass, nettle, and chickweed, which are easier to kill than perennial plants and generally die when the foliage or stems are destroyed.
- Systemic weed killers move within a weed after they are absorbed, usually down to the roots, destroying the whole plant from the bottom up. You can expect to wait several days to several weeks to see results, although unlike contact weed killers, systemic products generally won’t state the specific period of time it takes to kill weeds. They’re a good option for perennial weeds, such as dandelion, poison ivy, or ragweed, which are typically more difficult to kill because of their deeper roots.
Persistence is a measure of how long after application a weed killer remains in the soil and provides weed control before you have to reapply it.
- More temporary weed killers degrade in soil within a few days to weeks, which forces you to reapply the product often to keep weeds at bay but allows you to quickly replant other plants in the area without interrupting their growth. This makes them a better option for gardens where you intend to plant flowers or vegetables in the near future or places where weeds seldom grow, like gaps between paver stones in the yard.
- Longer-lasting weed killers stay in the soil and keep new weeds from growing in the application area for months or even a year after application. They’re a good option for lawns or gardens where you need lasting weed control, but they can also inhibit the germination of new plants you grow in the area for a longer period of time, so don’t use in areas where you plan to add new crops in the near future.
Our Top Picks
1. BEST PRE-EMERGENT WEED KILLER: The Andersons Pro Turf Barricade Granular Pre-Emergent Weed Control
Nip baby weeds in the bud with this selective pre-emergent weed killer best suited for turfgrass and garden beds. It helps preventsover 30 types of weeds from growing—without harming most trees, shrubs, vines, or flowers nearby. Apply this granular weed killer to the soil or mulch and then water (or wait for the rain) to establish a protective soil barrier to block weed growth for four months to one year. One 18-pound bag covers between 2,500 to 10,000 square feet.
2. BEST POST-EMERGENT WEED KILLER: Green Gobbler Vinegar Weed & Grass Killer
Sold in a one-gallon bottle that covers 1,200 square feet, this non-selective post-emergent herbicide works to control crabgrass, dandelion, and other pesky weeds, using a potent, pet-safe vinegar formula. Because it’s a non-specific weed killer, it’s best used near fence lines, pools, and patios, or in driveway or sidewalk cracks. To apply, fill a pump sprayer with the liquid herbicide or attach the supplied trigger sprayer, then point and spray; the fast-acting product can kill weeds within 24 hours and degrades in soil within days.
3. BEST SELECTIVE WEED KILLER: Southern Ag Amine 24-D Weed Killer
This selective post-emergent herbicide targets weeds like dandelion and chickweed but does not affect plants that aren’t weeds. Dilute two to three tablespoons of the liquid concentrate in three to five gallons of water and spread with a hand-pump sprayer or a hose-end sprayer. It’s suited for use on lawns, pastures, rangelands, and along fences. The product provides weed control for six months to one year depending on the application site, and the one-quart bottle covers 21,000 to 32,000 square feet.
4. BEST CONTACT WEED KILLER: Spectracide Weed & Grass Killer Concentrate
This non-selective contact weed killer harnesses the fast-acting herbicide diquat dibromide to eliminate weeds and other vegetation on contact. Dilute 10 tablespoons of the liquid concentrate in a gallon of water, apply with a tank sprayer to the foliage of weeds like dandelion, clover, and ivy. The product typically works within 24 hours, and you can reapply it after seven days. The 16-ounce concentrate covers up to 1,500 square feet.
5. BEST SYSTEMIC WEED KILLER: Ortho Nutsedge Killer for Lawns
To deal with the most stubborn lawn weeds, consider this sulfentrazone-based selective post-emergent herbicide. It can eliminate 50 hard-to-kill weeds like purple nutsedge and kyllinga without damaging the grass or tolerant surrounding plants. Application of this liquid formula is made easy by the built-in hose-end sprayer: Just connect the sprayer to your hose, turn on the water, and spray the systemic herbicide directly on weeds. You can reapply the herbicide after one month, and the 32-ounce bottle covers up to 5,000 square feet.