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can you spot treat weeds in newly seeded lawn

Spot Treating Weeds

In a healthy lawn, weeds should be minimized. It’s only in an unhealthy lawn where weeds become major problems.

If you have a thick, green lawn, then weeds should not be a problem, but they will show up from year to year. Instead of putting down a selective herbicide over the entire lawn, it is better to spot treat the occasional weed with a small hand sprayer.

Not only is this less expensive, but it is better for the entire yard. Herbicides, even selective herbicides, put stress on turf grass plants. Avoiding the stress on the entire lawn is better.

Spot treat whenever possible. Early spring or fall treatments are usually best. Younger weeds are easier to control than mature weeds.

Precautions when applying herbicides:

Do not apply during hot days because they may injure the lawn.

Do not apply during the rain. Broad-leaf herbicides require 24 hours of dry weather to ensure good uptake by the plant.

How to Kill Lawn Weeds

Broadleaf weeds can spread rapidly and suffocate your lawn. The longer you wait to combat lawn weeds, the harder it is to defeat them. If you want a green, uniform lawn, then managing lawn weeds should be a big part of your lawn care program.

The main problem I have with fertilizer companies and their step programs is they convince you that the best way to kill weeds that are already established is to apply one of their fertilizer and granular herbicide mixtures.

In my experience these products very rarely work. While companies like to sell you the convenience of fertilizing and controlling established weeds with the same application, it’s not the best way.

If you already have broadleaf weeds in your lawn it is very unlikely that one of these mixes will kill them.

Why Don’t Granular Herbicides Work on Established Weeds?

Granular post-emergent herbicides are herbicides you apply to established weeds. Granular post emergent herbicides are commonly found in products like Weed & Feed, or other 4 step programs that fertilizer companies promote.

Under perfect conditions these products sometimes work. But perfect conditions are hard to come by.

For starters the lawn needs to be a little wet to get the granular herbicide to stick to the weed leaves. Even then, most of the herbicide ends up bouncing off the weed leaves.

If you are lucky enough to get the correct moisture for the herbicide to stick to the weeds leaves, you have to wish for some additional luck that you don’t get any rain for at least 24 hours. Otherwise the herbicide will wash off the leaves and this will all be for nothing.

Also, broadcasting a post-emergent herbicide over your entire lawn is a waste. Chances are there are just some specific areas that require herbicide so I recommend spot treating those problem areas instead of putting expensive chemicals over your entire lawn.

Spot Treat Lawn Using Liquid Herbicide

Spot treating your lawn means going around your lawn with a liquid herbicide and spraying just the weeds. There are a lot of products that are safe to use on your lawn. A lot of these products even come with an applicator.

I really like Ortho Weed B Gone for spot treating lawn weeds. If you have a lot of weeds consider buying the concentrate here to save some money: Ortho Weed B Gone Concentrate. The concentrate is meant to be mixed in a tank sprayer.

For tank sprayers you can either get a small 1-2 gallon tank or a larger 4 gallon tank. The 1-2 gallon tank is usually fine for spot treating: 1 Gallon Tank Sprayer

Ortho Weed B Gone is designed to disrupt the growth of a lot of different kinds of broadleaf weeds including dandelions, clover, and crabgrass.

To treat your lawn, I recommend walking your lawn frequently (every week) and spraying any lawn weeds you see. This will help you stay on top of weeds and will prevent them from spreading. Many broadleaf weeds require a follow up treatment.

Also, it is highly recommend you mix a little Surfactant in with the Ortho Weed B gone, or any other liquid post emergent herbicide. The Surfactant helps the herbicide stick to the leaf of the plants. When broadleaf weeds are established they can get a waxy coating on their leaves that makes the herbicide hard to stick to. If you’ve ever been unsuccessful with liquid post emergent herbicides it’s likely this was the problem. Mixing in a little Surfactant can make a big difference. You can purchase Surfactant here: Surfactant

Blanket Spray If There’s a Lot of Weeds

What if you have so many weeds that spot treating isn’t an option?

If you have a lot of weeds mixed in with your lawn it might seem ridiculous to go around and spray each individual weed.

Instead, you’re better off blanket spraying your entire lawn. Blanket spraying usually requires a larger 4 gallon tank sprayer with a handle for pumping: 4 Gallon Tank Sprayer

You simply mix a liquid herbicide with water (according to the blanket application instructions on the label) and walk your entire lawn while spraying. I like to go up and down in rows, usually following my mowing lines.

You can blanket spray using the same Ortho Weed B Gone product as mentioned above in the ‘Spot Spraying’ section or you can use a product called Tenacity.

Tenacity, is a great herbicide for blanket spraying because it is usually a little more forgiving if you over apply. It can also be effective in controlling some grassy weeds such as Poa Annua.

Another bonus of Tenacity is if you’re planning on seeding areas of your lawn or planning on a lawn renovation this is a safe product to use. Many other liquid herbicides recommend pausing applications at least a month before seeding. With Tenacity you can apply leading up to your renovation. Usually you can even treat weeds at the same time as seeding (exception with fine fescue, and some other grass types, always read label).

Tenacity does have a couple of drawbacks. For starters it takes awhile to see results. It could take up to 2-3 weeks before weeds die back. Also, because it works by blocking photosynthesis in weeds, you’ll see the weeds turn a bleached white color. This will make weeds stand out as they are dying back. Lastly, you might see some temporary bleaching of your grass. This is usually temporary and grass will eventually green back up.

Just like with spot treating, mixing Surfactant into your liquid herbicide will make blank spraying more effective.

Prevention with Pre-Emergent Herbicides

Unlike granular post-emergent herbicides, granular pre-emergent herbicides can work very well in preventing lawn weeds from becoming established. I strongly recommend using pre-emergent herbicides at 3 specific times during the year. Check out my custom lawn care program to see what pre-emergent to apply and when.

Pre-emergent herbicides prevent crabgrass, as well as other broadleaf weeds from germinating. Prevention is definitely the best method for dealing with broadleaf weeds.

Are There Any Chemical Free Ways to Kill Weeds in Lawn?

There’s always the manual way, which is actually the most effective way. There is a great weed grabbing tool that many people use to pull weeds completely out of their lawn, including the weeds root system.

It is especially effective for removing dandelions since dandelions have a long tap root that can be hard to rip out.

Renovate Lawn to Combat Weeds

If your lawn is overwhelmed with weeds you might be convinced you have to rip everything out and start over. Before doing so, consider core aerating and overseeding. Core aerating and overseeding, can drastically improve your lawn.

If you want to go a step further, top dressing your lawn, in addition to core aerating and overseeding is the ultimate lawn renovation.

As usual the best recommendation I can give for combating lawn weeds is sticking to a good lawn care program and maintaining a healthy lawn.

How to Get Rid of the Weeds in the Lawn Without Killing the Grass

There is no doubt that weeds are the biggest problem that could make an otherwise perfect lawn look poorly maintained. They develop quickly and before you know it, they are already stealing the soil’s nutrients and getting in the way of the grass’ proper growth.

But how can you get rid of the weeds without harming the grass? We are glad you asked! Because we know of a few tricks you can try to make the pesky intruders disappear.

Table of Content:

Natural ways to kill weeds without harming the grass

Chemical weed killers are a dime a dozen. A main concern among lawn owners, though, is the effect these chemicals have on the environment and the residue that will be left after treatment. If you are also worried, then testing eco-friendly home remedies for permanently getting rid of weeds is worth a try. Unlike chemical products, though, take into consideration the fact that these may take more time to work and may not give the expected results with specific types of weeds.

Killing weeds with vinegar

Vinegar can serve many purposes around the house. It is considered a toxic-free cleaning alternative and it can help you kill off the weeds in the lawn the same way it helps you remove germs.

Remember, though, that it’s best to stick to white vinegar, which is broadly distributed in stores. The most suitable product to help you get rid of weeds naturally should contain 3% to 5% acetic acid. Due to its acidic properties, though, it needs to be applied carefully and in the right manner, so it does not harm the soil.

Stronger vinegar with up to 20 % acetic acid, also known as horticultural vinegar, is available, too. While you may be tempted to use it because it looks stronger and, therefore, should provide more effective weed control, better reconsider. It can be dangerous for both your health and the environment because of its corrosive power.

It is better to test with the less aggressive vinegar. And once you get it, here is what you have to do next:

Step 1: Get an empty and clean spray bottle.

Step 2: Pour the vinegar in. You can mix it with water or add soap, as vinegar and 1-2 tablespoons of dish soap could be an even more effective weed killer.

Step 3: Stir well until the ingredients blend.

Step 4: Apply the natural solution to the weeds’ covered area, but be careful not to get it on the grass or the soil itself. Just cover the plant you want to remove. Apply it only when there is a dry and sunny weather forecast for at least a few days since this will speed up the drying process. This will also give you peace of mind that rain will not wash off the vinegar solution and transfer it into the soil.

Step 5: Check the results in a few hours and follow up with more spraying if needed.

Step 6: Remove the weed when it’s dead.

The amount of weed-killing mixture you prepare will depend on the ground you need to cover. After a few hours the weeds should begin to dry, changing their colour from green to yellow. Keep in mind, though, that several treatments may be required before the weed is dead for good.

Using boiling water to kill weeds

This is a considerably harmless way to tackle those pesky green intruders in your lawn. Pouring hot water on the weeds also qualifies as the cheapest option, since all you need is plain H2O.

The boiling water method is most convenient for killing large patches of weeds since it’s not always easy to stop the water from spreading to the grass. The liquid will not harm the soil but could still kill some grass blades in proximity. If that happens, consider planting new seeds on the spot.

Once you boil enough water, try pouring it on the weed’s leaves, as well as the stem. However, seeds that are already in the ground will hardly be affected by the water. If you see new weeds emerging in the same area, make sure you remove them before they have a chance to grow and take over your lawn.

Since this is hot water, be extra careful not to get any of it on yourself. Keep your hands and feet covered and as far away as possible when treating the weed-affected area.

Water can kill weeds in another form – as steam. For the purpose, you will need a gardening machine with steaming power. Thanks to the powerful stream flow it produces, the weeds turn from green to black pretty fast. However, this is a more suitable method for treating paved areas, large weed-infested areas or just the weeds in the edges of your lawn.

Pulling weeds by hand

Hand plucking is the easiest, cost-free and efficient method to prevent an infestation. Usually done during soil preparation, this is without a doubt also the safest way to enjoy a weed-free lawn. While you may not be very excited about it at first, in time you may find out that this is actually beneficial for both you and your lawn. In fact, hand weeding is considered a stress-relieving activity by many gardeners.

It is important to take those weeds out the moment you see them grow. While it may be hard and it may take you more time, you have to be careful and take the whole weed out, roots and all. This will guarantee the efficiency of this method.

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The chemical way to remove grass weeds without killing the lawn

If you are set on trying some specialised products for eliminating the unwanted plants in your lawn, then you will need the right herbicide. There are basically two types:

  • Selective herbicides – These are meant to kill specific kinds of weeds. Such are the broadleaf herbicides, which provide control over dandelion, bindii, clover and the likes.
  • Non-selective herbicides – As the name suggests, these are more generic products. They can kill everything and usually work down to the root.

Preventive measures to keep the weeds away

Once you get the weeds out, they’d better stay out. For that to happen, though, you will have to pay attention to your lawn regularly and take measures early. Some of the things you can do include:

  • Fertilising twice a year – This will guarantee that your grass will stay strong and be less likely to develop weeds. The process is best done either early in the spring, when the grass is waking up, or in autumn when the lawn is going into dormancy.
  • Applying the proper weed control products – The success of a weed killer depends on your ability to choose and apply it at the right time. It all comes down to pre-emergent and post-emergent herbicides. The first ones are meant to block germination of the weed seeds, while the latter are meant to kill already existing weeds. Some of those are even combined with fertilisers, so your lawn can benefit even more from the application. If you are looking for an organic pre-emergent weed killer, you can give corn gluten meal a try.

All weed killing products are available in the specialised store. We suggest that you consult with someone if you are having doubts about a product’s efficiency and suitability for your lawn. You can always get a lawn care specialist in the area to inspect your lawn and take care of a weed situation or another issue for you.


  • Vinegar may be a natural weed killer, but you have to be careful what kind you use. Stick only to milder products with 3%-5% acetic acid.
  • Before opting for chemical weed control, make sure you have the right products. Keep in mind the following things: what’s the type of weed, are you tackling full-grown weeds or taking care of the seeds, too.
  • The most certain way to always have a weed-free lawn is to give it your attention and care regularly. Having a busy schedule doesn’t always leave much time for it, but having a reliable and skilled lawn care professional at your disposal can make a difference.

Are the weeds taking over?

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  • Last update: November 2, 2021

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