What Kills Grass And Weeds Fast? (Find OUT)

Grass and weed control can be a tough job, but there are plenty of ways to fight back. From herbicides to manual labor, there’s no shortage of options for keeping your lawn looking great. In this article, we’ll cover some of the most effective ways to kill grass and weeds.


Dicamba is a popular herbicide that’s used to kill broadleaf weeds in taller grasses. It works by preventing the plant from producing protein, which eventually kills the plant.

The best time to apply dicamba is late summer or early fall when temperatures are warm and soil moisture is high. 

You can also apply it in late winter if you’re trying to prevent new growth and regrowth. Some common weeds dicamba kills include:

  • Chickweed
  • Clover (white clover)
  • Dandelion (espcially yellow)


Glyphosate is a non-selective herbicide that kills broadleaf plants, grasses and sedges. Glyphosate is also called Monsanto’s Roundup® or Roundup Ready®.

It’s a systemic herbicide, which means it moves throughout the plant and into its roots. The chemical formula for glyphosate is: N-(phosphonomethyl)glycine (C3H8NO5P).

2, 4-D

2, 4-D is a broad spectrum herbicide that kills a wide range of broadleaf weeds and grasses. It’s used to control weeds in lawns, gardens, golf courses and agricultural crops. 2, 4-D is a contact herbicide and it works by disrupting protein synthesis in the plant cell. 

The most common side effects of 2, 4-D exposure include nausea; vomiting; dizziness; headache; blurred vision; dry eyes or skin; swelling of the lips or tongue followed by excessive salivation (drooling), diarrhea and muscle weakness.

Weed and feed

Weed and feed is a fertilizer and herbicide that’s applied to your lawn during spring or autumn. It can be used on any type of grass, but it’s most often used for cool season grasses like fescue (which looks like this) and rye (which looks like this).

If you’re new to weed and feed products, they may seem convenient: all in one product! But don’t let their convenience fool you weed and feeds can be very dangerous if they’re not properly applied. 

If too much fertilizer is applied at once, your lawn may turn brown or yellow due to an overdose; if too much herbicide is applied at once, your lawn will die completely.

Weed and feed products are also problematic because they kill both weeds AND desirable plants such as clover (a nitrogen-fixing plant), dandelions (pretty flowers), wild violets (pretty flowers), etc., instead of just targeting the weeds themselves.


Quinclorac is a selective herbicide that kills broadleaf weeds, but not turfgrass or other grasses. It is used on turf, ornamentals and other plants. 

It is used on residential, commercial and industrial sites. In agriculture it is used to control broadleaf weeds in crops like vegetables (tomatoes etc), fruit trees and field crops such as soybeans and corn.


Sulfentrazone is an herbicide that’s been around for years, but it’s still commonly used in agriculture and on lawns. 

This chemical works by interrupting the plant’s photosynthesis process, which eventually kills the weed. It can take several weeks for this to happen and some weeds will take longer than others because of their root structure or other factors.

Sulfentrazone can be applied before you seed your lawn because it won’t harm regular grass plants; however, you should avoid spraying during hot weather (above 90 degrees). 

Also keep in mind that sulfentrazone isn’t effective against perennial weeds like dandelions or crabgrass—you’ll have to use another method if those are what you’re trying to get rid of!


Imazapyr is a selective herbicide that kills broadleaf weeds and grasses. It is used to control annual and perennial weeds in corn, soybeans, cotton, rice and other crops. 

Imazapyr slowly dissolves in water, soil or plant tissue, then moves through the plant’s vascular system until it reaches the roots where it disrupts cell division.


Triclopyr is a selective herbicide that kills broadleaf weeds and grasses. It is used on lawns, around ornamental plants and shrubs, in pastures and rangeland to control woody brush, vines and young trees.

It’s a systemic herbicide that moves throughout the plant to kill it. It works best when applied before weeds go to seed or flower. 

Triclopyr has been shown to be safe for people, pets and wildlife when used according to label directions.

Metsulfuron methyl

Metsulfuron methyl is a nonselective herbicide. It controls annual and perennial broadleaf weeds in corn, soybeans, wheat, rice, cotton and other crops. 

Metsulfuron methyl is used to control annual and perennial broadleaf weeds in turfgrass.

Metsulfuron methyl can be used as a spot treatment on individual weeds or as an over-the-top application with preemergence crop residue incorporation for control of winter annual grasses (dallis grass) in turfgrass established from sod or sprigs/rooted plugs (during fall/winter). 

In some situations, preemergence applications may not be effective if soil moisture conditions are too high during application or if growing seasons are warm enough for germination of the target weeds before first mowing occurs following application.

The best time to apply is when root growth slows due to cooler temperatures in late summer through fall at least 6 weeks before expected planting time. 

This provides time for weed growth regulators to work while weather conditions are favorable so they do not interfere with germination of small seeded cereals such as barley or oats if spring planting follows fall application of metsulfuron methyl products

Bromoxynil octanoate

Bromoxynil octanoate is a selective herbicide that is used for the control of broadleaf weeds in a wide range of crops and grasses. Bromoxynil octanoate is also used in the control of perennial weeds in turf.

(1) Bromoxynil octanoate acts as an inhibitor to photosynthesis, causing rapid wilting and death within 3-4 days (2).

(2) Bromoxynil octanoate is formulated as an emulsifiable concentrate containing 29% bromoxynil plus 70% emulsifier. The rate applied depends on soil type, weather conditions and weed species present (see Table 1).


Carfentrazone-ethyl is a selective, broad-spectrum herbicide that is classified as an ALS inhibitor. 

The active ingredient of carfentrazone-ethyl is carfentrazone, which is also known as 2-(4-chlorophenoxy) propanoic acid. It’s used on weeds such as dandelions, chickweed and clover.

Carfentrazone inhibits the production of adenosine triphosphate (ATP), which causes those cells to die off. 

When applied to plants it prevents the formation of protein in their chlorophyll molecules; this results in little or no green pigmentation being produced by the leaves and stems of many types of grasses and flowering plants including dandelions


There you have it! These are some of the best herbicides to use if you need to kill weeds and grass fast. 

You can use them in your garden or lawn and get rid of those pesky weeds once and for all.