How to Use a Weed Killer Most Effectively?
How to Use a Weed Killer Most Effectively?
5 (100%) 5 vote[s]
So, you have bought a grass killer to get rid of weeds once and for all. But how to use a weed killer efficiently to prevent additional expenses for buying an extra package? Also, the wrong application of a weed killer can make the problem of weeds even worse. That is why check the expert tips about using weed killers of all types. 

How to use different types of weed killers?

Herbicides are weed-killing pesticides. With the help of these products, you can get a perfect lawn, significantly increasing the yield of vegetables and fruits. However, to get the expected result – healthy and strong plants without any weeds, you need to understand how the product works and follow a few simple rules.

All weed killers are divided into:

  • Non-selective herbicides;
  • Selective herbicides;

Typically, non-selective herbicides such as Hurricane Forte and Roundup weed killer are used before cultivating the lawn or flowerbed.

How to Use a Weed Killer Most Effectively

Solid herbicides, mainly based on substances such as glyphosate, destroy virtually all plants. A wide variety of the products of selective action is capable of destroying, for example, chamomile or dandelions

When spraying a glyphosate-based weed killer, do not let it fall on the leaves of trees, even small concentrations of such a product can kill fruit trees and shrubs.

The use of soil herbicides is good when the weed spreads the seeds into the ground. Such drugs are applied directly to the ground. They adversely affect the weed seeds.

Systemic herbicides are one of the most popular types of seasonal grass killers, as they quickly and effectively affect weed growth. When such a grass killer gets on the weed, it not only affects the outer shells but also is absorbed into the plant. It spreads throughout the weed, which means that its action is aimed at destroying the root system. Of course, systemic products are not comparable to soil herbicides. Systemic herbicides can comprehensively affect the plant, and soil products affect only the seeds.

When is the best time to use weed killers?

It is best to use a weed killer in spring, a few weeks before cultivating the major plants and trees in your garden. The second treatment is done in 2-3 weeks to fully destroy weeds. In this case, the weeds left deep in the soil will be destroyed. The main thing to remember during the weed control on your lawn is to prevent the spread of seeds and destroy young plants before flowering. The weed seeds in the soil must deplete, and their number will decrease drastically. 

When is the best time to use weed killers?

In this case, you will be able to do local treatments or manual removal of weeds. In addition, the weeds that have reached a height of 6 inches or more are less vulnerable to herbicides. In this case, it is necessary to mow the overgrown weeds, give them to grow to 2.5 – 3 inches, and only then to apply a grass killer.

Factors to take into account before using a weed killer: 

  • Accuracy of dosing;
  • Processing of actively growing plants;
  • The season with the best temperature;
  • Feeding weeds with nitrogen increases the effect;
  • Accurate weed diagnosis must be done before applying a selective grass killer;

How to achieve the best result when using a weed killer?

Dosing accuracy is a must-use thing for effective treatment, especially when using selective herbicides. In addition, the temperature of the air and soil must be within the limits specified in the instruction of a specific product. As a rule, the best herbicides work in the range of 60 -77°F. In any case, the soil in the root layer should be warmed to 53° F or higher. 

Herbicides are most effective in the treatment of actively growing weeds, with a powerful and well-functioning root system.

It is definitely not necessary to treat weeds that are in a state of stress with a damaged root system after mowing. Penetrating from the leaves of the weeds to the roots, the herbicide “disconnects” its root system. However, herbicides are most effective for destroying the healthy, strong, actively growing weeds. For the same reason, it’s not necessary to cultivate immediately after treatment with non-selective herbicides or to mow the cultivated lawn.

What products can increase the effectiveness of most grass killers?

If you want to increase the effect of herbicides, apply them along with nitrogen fertilizers. 

The most effective option – the combinatory application of ammonium nitrate and herbicides. 

Apply the required amount of 0.2-0.4% solution of ammonium nitrate several days before the treatment with a herbicide. Or spread 0.02 – 0.03 lbs of this fertilizer per 10 sq. ft. on the plot after the medium irrigation, a week before the application.

Safety rules when using a weed killer

If weather forecasters do not promise good weather after the use of herbicides (and it is impossible to delay the treatments), consider adding adhesives to the mixture. In addition, their use is perhaps the only way to reduce the dose of herbicides without compromising on effectiveness. Adhesives must have a biological origin, for example, Liposam, to prevent the spread of chemicals to the soil and cultivated plants (if you are going to use it with selective herbicides). The effectiveness of herbicides along with adhesives is dramatically increased.

Safety rules when using a weed killer

Can a weed killer harm a person? The instructions for herbicides always indicate the level of danger and toxicity to humans. All substances that are part of the selected product have various degrees of toxicity.

Mostly, the herbicides are medium-toxic to humans. But they can be very bad for little kids and pets, especially liquid products. That’s why, herbicide treatments must be applied only when you wear protective clothes, rubber gloves, respirators, and goggles.

Important advice: when using a weed killer, protect mucous membranes and exposed skin from any contact with the grass killer.

What are the effects of weed killer on skin? Rash and redness is possible. Wash with water if you have a herbicide on skin.

If the herbicide enters the mucous membranes, the digestive tract should be washed with plenty of water – vomit and then consult a doctor.

After the application of a weed killer, the sprayer is thoroughly washed with a solution of detergent until the full removal of the product’s residue.

Things to consider when reading the label

Before using a weed killer, thoroughly read the label of a grass-killing product. Remember – most herbicides are manufactured for vegetative weeds. Check the label and find the information about the method of application, the time of action, properties. 

When buying herbicides for selective action, check the label for such information:

  • Shelf life;
  • The weed type it can kill;
  • The consumption rates;
  • Methods of application;

Using a weed killer: weather conditions

It’s useless to use a weed killer on a rainy and windy day. Apply the products when the weather is warm and calm (the wind speed must be not more than 6.5 mph), mainly in the early morning and evening hours. In the daytime use a grass killer only on cool and cloudy days. However, the air temperature is also important. For example, the hotter, drier and sunnier it is outside, the faster the glyphosate herbicides work.

Never apply a weed killer in a strong wind – it can spread the herbicide on other plants, which will cause the damage. 

When is it the best time of the year to use a weed killer? Keep in mind that weed killers are more effective in autumn than in spring when it comes to already grown weeds. 

Common trips for using any weed killer: 

  • If you use a liquid grass killer, pick a good sprayer. The option of “bucket with a broom”, which is common among some owners of small plots, is not acceptable when you use herbicides;
  • Never apply the herbicides on the plants that are in a state of stress – for instance, when you mow, when the temperature is too high or low. In this case, the effectiveness of grass killers can be dramatically reduced;
  • Use a grass killer at least 3 hours after the irrigation, watering or rain. It’s better to switch off the irrigation system for 12-24 hours to make the herbicide more effective.
  • Of course, it’s better to apply herbicides locally, spraying them only the most clogged areas;
  • Even if your lawn or field is in perfect condition, it’s required to repeat the herbicide treatment every 3 years. The best weed killers for lawn are selective and spot herbicides;

How often should you use a weed killer?

This depends on the chosen type of weed killer. That is why I insist on reading the label because each manufacturer has different instructions.

Some grass killers are enough only for one annual treatment. But most of them are good for 2 full lawn treatments once a year. Just make sure you buy a herbicide that is suitable for the whole lawn coverage instead of spot treatments. 

Expert gardeners recommend no more than 2 treatments per year with 2 different grass killers (must include various active components). After getting rid of established weeds, repeat the treatment in September in the subsequent years. If necessary, use spot herbicides for certain weeds in spring and summer. 

Final thoughts

Using a grass killer is not that difficult. Just read the label and follow the instructions. You won’t need a complete lawn treatment for several years if you follow the expert tips and manufacturer’s label. However, it is better to prevent weeds than killing them, so don’t forget to mow and cultivate the plants regularly.


Hello, my name is Jane Smith and I’m an author of this blog. Using weed killer seems inevitable, especially when highly recommended organic options fail to get rid of weeds.

Related Posts

How to Get Rid of Crabgrass without Chemicals and with Herbicides?

How to Get Rid of Crabgrass without Chemicals and with Herbicides?

So many weeds can invade the perfect lawn in early spring and stay for a whole year if not treated. One of such weeds is red-colored crabgrass (the botanical name is Digitaria). What is crabgrass bad? Digitaria can grow annually up to 12 – 20 inches on any type of soil in the spots where…

How Long to Keep Dogs Off Grass After Using Weed Killers

How Long to Keep Dogs Off Grass After Using Weed Killers

So, do you need to destroy weeds in your garden or lawn? You carefully read the label and apply the products according to the instructions. Most herbicides need at least a few days to destroy the unwanted vegetation completely. But how much time is required to keep people and pets off the lawn after using…

How Long Does it Take for a Weed Killer to Work

How Long Does it Take for a Weed Killer to Work

All herbicides are aimed at getting rid of weeds and vegetation that you don’t want to see in a garden or crop field. The most common types of weeds that gardeners want to eliminate are moss, clovers, dandelions. The majority of weed killers completely destroy or damage the vegetation that prevents good crops or flowers…

Leave A Comment

Your email address will not be published. Required fields are marked *