Will borax kill grass if sprinkled directly on it or sprayed as an aqueous solution? This is a question inquisitive turf owners are very curious to find out.

Will Borax Kill Grass

This is because this cleaning product is quite effective in lawn care regarding getting rid of pests and weed control.

Find out if your sweet grass is at risk from borax in this tell-all guide.

Will Borax Kill The Grass On My Lawn?

Yes, borax can kill lawn grass for a significant amount of time when it comes in contact with it. The concentration and quantity of borax needed to kill grass are higher than that needed to kill weeds and pests in the garden.

Boron is the active ingredient of borax, and in large quantities, it has the potential to kill grass, weeds, and plants. You might know of borax, known otherwise as sodium borate, only as a household cleaning solution. This boron concentrate is used for several purposes when caring for lawns and grass.

– Stops the Growth

Boron is a micronutrient that is needed by the grass for its normal growth and development. However, only a tiny quantity of boron is needed and tolerated by the grass. Which means that the grass will become weaker than usual and it will slowly perish.

– Grass May Become Fatal

Even slightly higher quantities of boron, like those in borax, are toxic for grass and kill it. Because borax usually comes in liquid form, it can sleep within the soil to burn roots and kill grass permanently. 

Whenever any patch of grass is exposed to borax and not immediately washed off, it simultaneously burns grass blades and roots. The grass first turns yellow around the edges and then becomes fully discolored, this is how it would lose the strength to produce chlorophyll and to prosper. It then turns brown and dies off, turning dry and crisp on the touch.

Within a day, the exposed patch of grass will be dead, and you will have to pull it out manually and reseed the area again.

– Kill Pests And Bugs

Borax is great at killing grass and weeds and will help eradicate pests and bugs from your lawn. They are particularly effective in removing ants that might eat grass blades and plant leaves in the lawn. Look around to see where these ants have created an anthill and sprinkle powdered boron all over it. Spread boron powder randomly around the lawn away from the grass as well.

Borax help eradicate pests and bugs from your lawn

The ants are attracted to the flakes of borax as a potential food source and will carry it back to their colonies, these would, at times, be harmless to the grass, and even beneficial. Naturally, it is toxic for them and will help eliminate ants in no time. Pests like grubs and earthworms remain unaffected by small quantities of borax and will need a stronger solution to be eradicated.

Because borax needs to be more concentrated to kill pests, add a teaspoon of its powdered form in a spray bottle. Put the lid back on the bottle, then shake and mix well, so it dissolves completely in water.

First, identify parts of the lawn that show clear-cut grub damage or wormholes and spray on these spots to kill these pests. This borax mixture has to be sprayed every month until the pest problem is resolved. You cannot spray it more often than this lest soil contamination starts happening.

Can Borax Be A Fertilizer In Controlled Amounts?

Yes, borax can be used as a fertilizer when it is placed in small amounts, because it will help in fixing the boron deficiency in the grass. You can use it either as a powder fertilizer and spread around the grass, or dilute it as a liquid fertilizer.

Using commercial fertilizers for a long time can cause the depletion of boron from the soil. If the soil in your backyard is sandy, to begin with, then this is a problem you are more likely to encounter. If this is the case, borax is an effective way of rapidly adding the required amount of boron to the soil. 

A boron deficiency can only be diagnosed with surety after getting the soil tested professionally. We recommend conducting soil testing at the beginning of each spring growth season. Still, certain signs give you a rough idea that your grass and soil are undergoing a boron deficiency. Plant grass blades and leaf tips begin to die and turn brown. 

– As Powder Fertilizer

Small quantities of powdered borax can be used as dry fertilizer to eliminate a boron deficiency. Six tablespoons of borax from a trusted manufacturer should be enough for medium to large-sized lawns. Take out your seed spreader, and spread this powder evenly over the lawn. Take a tiller to superficially mix the borax powder into the top layers of the soil.

– As Liquid Fertilizer

Alternatively, mix just one tablespoon of borax in one gallon of water to make a liquid fertilizer. You can keep the solution weak initially to stay on the safe side. Sprinkle this solution all over the lawn, leaving no patch untouched.

If plants are in your lawn and you want to go for a foliar spray, make the solution weaker by mixing just two ounces of borax in five gallons of water. Try not to drench the plants with this spray; instead, lightly sprinkle it on them.

Can Borax Be Beneficial to Kill Weeds Permanently?

Yes, you can use borax in a beneficial way to kill weeds permanently. Ways that you can do it is either by diluting the solution and using it, or spraying on the weeds. Moreover, you can also use a paint brush and tip the drops on the weeds.

Borax has always been known to be an effective homemade weed killer because of its high boron concentration. It works more rapidly on broadleaf plants and weeds than on narrow grass blades because they have more surface area for absorption. 

Some of the most common weeds that attack lawns in the US are luckily easily susceptible to borax as a herbicide. These include annoying species like creeping charlie, bindweed, wild morning glory, and the various types of creeping ivy. Like how chlorine bleach kills weeds, borax is another good option in your pantry.

– Dilute the Solution

Collect one gallon of clean, filtered water and add half a cup of borax to make a strong weed killer solution. If you use powdered borax, keep mixing it until it completely dissolves in the water.

Put on clothes that leave no part of your skin exposed and sturdy rubber gloves before working with borax. Borax produces caustic burns to the skin on accidental application, so it’s best to protect yourself with a facemask and goggles.

– Spray the Solution 

Putting a little bit of this solution in a pump sprayer will make its application much easier. Identify the patches in the lawn where these weeds are growing and spray specifically on these patches only to protect the surrounding healthy grass.

– Brush the Fertilizer

Another safe application method is to use a brush to paint this solution directly on weed leaves. This method takes longer; the solution doesn’t seep underground to kill the roots.

Brush the Fertilizer

Some people sprinkle powdered borax on the weed patches and then water it very lightly. This method works too, but there is a risk of the chemical washing off the surrounding grass.

The boron in borax tends to collect in the topsoil and produce long-term toxicity. Hence, it can be used only once a year as a herbicide, and that too for no more than two consecutive years.


Before we end this guide on using borax on grass, here are some pointers to take home.

  • If you ask us whether borax or diluted bleach kills grass, then the answer to that is yes, it would.
  • Borax is a good source of the micronutrient boron, and you can use it in small amounts as a fertilizer.
  • Just sprinkling borax in powdered form on the weeds growing in the lawn or cracks between the tiles will kill the weeds.

After reading our guide, it would be best to stop using borax in your lawn because it can kill your grass. If used carefully and in the right quantity, this household product can greatly help various things.

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