Understanding Different Herbicide Types and Their Applications

From mowing to manually pulling them out, lawn weeds can be removed via a number of different methods. However, the most effective strategy is often to use a herbicide, especially if your lawn is large and the weed problem is widespread.

In this post, we’ll be talking about the different types of herbicides and their applications to give you a better understanding of how to use them effectively.

What are herbicides?

recognition herbicide kit


Herbicides, sometimes known as weed killers, are substances designed to control the spread and growth of undesirable plants AKA, weeds. They are often chemical solutions that are designed specifically to target various species of plants. They can be used as a preventative measure or when weeds are already present in your lawn or garden.

How do herbicides work?

Herbicides work by hampering the growth of weeds, particularly in the processes of photosynthesis and cell division. A herbicide will actively prevent weeds from absorbing nutrients from the soil which reduces their ability to grow and spread across your lawn.

By interrupting the natural growth cycle of weeds, their ability to reproduce is limited which ultimately leads to the death of the weeds. By applying several rounds of herbicides, your lawn can transition from a weed patch to golf course lawn quality.


Related Reading: Step-By-Step Guide for Getting a Golf Course Lawn


Why are herbicides important?

Herbicides are necessary to control the growth and spread of weeds.

If left unchecked, weeds can lead to a number of lawn issues:

  • Weeds compete with your grass for the same nutrients. If weeds are left to grow and spread, they eventually weaken your grass and damage the health of your lawn.
  • Weeds detract from the visual appeal of your lawn. Weeds are often different shapes, sizes, and colors when compared to your lawn. Their presence detracts from the overall aesthetic and visual appeal of your lawn.
  • Weeds thin your lawn. If weeds are allowed to take over, they begin to replace areas where grass would normally grow, effectively thinning the lawn and leaving patches with little to no grass.
  • Weeds are invasive. Invasive weeds could potentially ruin local biodiversity by disrupting your lawn’s ecosystem.
  • Weeds attract pests. Certain weeds create favorable conditions for pests and even diseases to flourish. They can become hosts to certain kinds of parasites that may cause widespread damage to your lawn.
  • Weeds interfere with using your lawn. If you use your lawn for things like sunbathing, games, or other outdoor activities, then weeds can interfere with these activities.
  • Weeds are a recurring issue. Manually pulling out or cutting weeds usually doesn’t work because they produce a lot of seeds that stay in the soil. This creates a recurring problem if it isn’t dealt with correctly.

As you can see, it’s important to control weed growth and spread in your lawn if you want it to remain healthy. Thankfully, the use of herbicides is a quick and effective way to control weeds in your lawn.

What types of weeds grow on your lawn?

Identifying the type of weed on your lawn will help in the long run because you can choose the right herbicides to eliminate weeds without killing your grass.

Grassy Weeds

poa annua

Grassy weeds are a common type of weed and should not be confused with domestic grass that is used for lawns. Some common examples include crabgrass, annual bluegrass (poa annua), and quackgrass.

These can sometimes be mistaken for the grass growing on your lawn, but there are some telltale signs that differentiate them. This includes slight color differences and textures in your lawn or an uneven patch of grass.

Related Reading: Which Types Weeds Look Like Grass

Sedge Weeds


Sedge weeds are similar to grass weeds, so they may be difficult to identify without experience. They are usually more common in warmer parts of the country and will typically grow in moist areas of your lawn. Some examples include yellow nutsedge, globe sedge, and kyllinga.

Unlike grass weeds, sedge weed stems are usually triangular and solid. They are easy to spot because they will overtake a patch of your lawn with different colors due to their flower-bearing stems.


Related Reading: Best Nutsedge Weed Killers


Broadleaf Weeds

broadleaf weeds

Broadleaf weeds are the most common type of weed found on lawns. As the name suggests, they can be identified by their broad leaves. They also often have flowers, such as common varieties like dandelions, henbit, and clover.

Since broadleaf weeds are easy to identify, they can often be pulled out from your lawn manually if you only see a few. If you have a lawn overrun with broadleaf weeds, herbicides are a better choice for controlling them.

What types of herbicides are there?

To make clearing weeds more efficient, it’s a good idea to understand the different types of herbicides and their applications.

Let’s start with the two selectivity categories of herbicide: selective and non-selective.

Selective Herbicides

celsius certainty herbicide kit

A selective herbicide targets certain types of plants while leaving others unaffected. It’s used mainly for situations where the offending weed has been identified and you want to maintain the health of surrounding plants and grass. It’s worth noting that some temporary damage may occur to the non-target plants that are sprayed with the herbicides.

Examples of selective herbicides are 2,4-D, and dicamba; herbicides designed to control broadleaf weeds in grassy areas. They specifically target broadleaf plants while minimizing the impact on surrounding grasses.

Non-Selective Herbicides

roundup herbicide

A non-selective herbicide is designed to control a larger number of plant species. This means they can target unwanted weeds, but will likely affect other kinds of vegetation too. They are a poor choice for controlling weeds within your lawn due to increased likelihood of damaging your turfgrass. 

Non-selective herbicides are more commonly used in non-lawn areas, such as a driveway or sidewalk that has weeds growing on it. An example of a non-selective herbicide is glyphosate which inhibits photosynthesis in plants, effectively removing a broad range of weeds.

Pre-emergent and post-emergent herbicides

measuring prodiamine

Herbicides can also be categorized by their timing terms. This refers to the times that they should be used in the weed’s growth cycle for maximum effectiveness. The two most common types are pre-emergent and post-emergent.

Pre-Emergent Herbicides

Pre-emergent herbicides are applied to the soil before the weed seeds have a chance to germinate, or before the appearance of seedlings. This can be seen as a proactive weed control solution that forms a barrier in the soil, thus preventing the emergence of seedlings. 

Pre-emergent herbicides typically need to be activated with water in order to form a barrier that effectively inhibits weed growth. This means you should either apply them when rain is in the forecast or run an irrigation cycle. They are available in liquid form or granular form, both of which are effective in controlling weed growth.

For best results, pre-emergent herbicides are applied twice during the growing season; spring and fall.


Post-Emergent Herbicides

Post-emergent herbicides are used to control weed growth after they have emerged from the soil. Unlike pre-emergent herbicides, they do not aim to form a barrier that inhibits weed growth. Instead, they are sprayed directly on the offending weeds with a fine droplet spray tip and then left to dry. This allows the foliage to absorb the herbicide, thus disrupting its biological processes and ultimately kills the weed.

Most post-emergent herbicides are selective because they are used to control weeds that are growing in your lawn without damaging your grass. To accomplish this, post-emergent herbicides are designed for use on specific grass types. In general you’ll find that post-emergent herbicides are broadly designed for use on either cool season or warm season grass

The objective is only to kill the weeds, so the herbicide used must be safe for use on your lawn. This is why it is important to correctly identify your grass type so the proper herbicide is used. You are matching 2 factors; the herbicide being safe for your grass and its ability to control the weed being targeted.


Related Reading: What Kind of Grass Do I Have in My Lawn?



Herbicide Application Tips

spraying herbicides

Herbicide application is easy to do assuming you have identified the weeds and possess the right safety and application equipment.

Here are some tips to help you out:

  • Wear protective gear at all times. Always wear personal protective equipment (PPE) when applying herbicides. This includes chemical-resistant gloves, goggles, and appropriate clothing to cover your skin. Herbicides vary in their toxicity and can cause skin and eye irritation.

  • Always follow label instructions. Make sure you read the label instructions provided on the product. These provide crucial information on application rates, safety precautions, and timing on when to use the products.

  • Purchase the right equipment. It’s important to have proper equipment when applying a herbicide, such as a backpack sprayer that comes with various tips for different application types.

  • Use a marker dye. A marker dye makes it easy to see where you have already applied the herbicide so that you don’t go over the same area several times.

  • Use a surfactant. A non-ionic surfactant will help the herbicide spread and stick to the weeds better. This helps improve herbicide effectiveness.

  • Minimize overspray. A single pass at a medium speed is enough to cover the weed and ensure it’s wet. If you’re dealing with a large area, avoid heavy overlaps as this may damage your lawn.

  • Don’t spray too far or close to the weeds. Around 12 to 14 inches of distance between the spray tip and the weed is a good distance to ensure the herbicide stays in the target area while providing good coverage.

  • Check the immediate weather forecast. Avoid spraying post-emergent herbicides within 4 hours of rainfall being expected. Heavy rain can wash away the herbicide before it has a chance to be absorbed. To minimize drift, avoid spraying herbicides when wind speed is 10 mph or greater.

  • Remember to clean your equipment thoroughly after the application, and rinse the backpack several times with clean water. 


    Related Reading: How to Kill Weeds Without Killing Your Grass


    Bye Bye Weeds

    With the right herbicides and processes, you can reclaim ownership of your lawn from a weed invasion. This puts you in a great position to create a lawn your neighbors will envy. 

    If you’re looking to keep your lawn healthy after weed treatment, check out our non-toxic biostimulants and fertilizers that make lawn care a breeze.