Introduction: Biodegradable and Safer Alternative for Commercial Herbicide

Picture of Biodegradable and Safer Alternative for Commercial Herbicide

With this Instructable we will learn how to make a safer and cheaper alternative to commercial herbicide. The ingredients are very easy to obtain at any supermarket or grocery store. Most of us have them already available at home. 

Step 1: Ingredients

Picture of Ingredients
You will need:
  • 1 gallon (3.78 liters) of white vinegar
  • 12 ounces (341.1 grams) approximately of salt for every gallon of vinegar
  • 1 tablespoon, more or less, of dishwashing detergent (biodegradable detergent preferably) will work as a surfactant
Mix and shake the ingredients on a safe plastic container.

Step 2: How to Use the Biodegradable Herbicide

Picture of How to Use the Biodegradable Herbicide

For maximum effect you should spray the solution on a very hot and sunny day over the undesirable plants using a small trigger sprayer or a pump sprayer. Cover the whole plant and roots and watch the weeds go.


SHOE0007 made it! (author)2017-03-09

Here more info on using the mold solution on a clover soil based pan. The humidity is 80% and the temp is average 20 degrees with Half light.

SHOE0007 (author)2017-03-06

Although it took 4 days of watering clover three times a day for 6 days eventually mold grew on the soil and the clover. It may have been very difficult to extract and keep the enzyme stable with my method.

However I have discovered that this selective Pathogenic plant mold if used in terms of dose and then exposed to 1-2% bleach could be used as a tough herbicide that could kill very tough plants like Poison Ivy.

Here are some images of the clover infected by the mold.

SHOE0007 (author)2017-02-19

At ph 6.0 the solution caaused at 50% the clovers to start to grow. So I have added a 6.66% active enzyme with acetic acid and a bit of sodium acetate at pH of 4.0.

SHOE0007 (author)2017-02-17

Here are some calculations to get the pH from 14 to 4 with acetic acid.

pH 14.

KOH(aq) + CH3COOH >>> CH3COOK + H20.

HOCl Lets pretend it too small to measure.

When neutralized with sodium thiosulfate pH was 14 means

very little effect.

4g/56.11 g = 0.0712 moles*10 = 0.712 moles per L.

1. Neutralize Lye.....

0.712 m*60 g (Atomic mass of acetic acid) = 42.72 g per L.

Requires 4.3 g Acetic acid.

Now pH is 7.0

Get it to 4.0

1% acetic acid m/v.

pH = -log (H+).

25 g*0.01 = 0.25 g.

0.25g/60g = 0.0042 moles Acetic acid.

Ka = [H+][A]/[HA].

Ka = 1.8*10^-5.

1.8*10^-5 = X2/0.0042 m.

X2 = 7.56*10^-8.

X = 2.749*10^-4.

pH = 3.5

Diluted this goes down a lot.

150 ml total/ 25 ml acetic acid mix * 0.25 g Acetic acid = 1.5 grams Acetic acid required in 150 ml water.

Requires 37.5 ml acetic acid for a total of 100 ml water.

SHOE0007 (author)2017-02-15

I have done more testing but for me at pH 5 (non diluted) and 6-7 for 25% the enzyme did not prevent growth of clover seed. Also reports say the optional temp is 45-50 degrees at 3-6 pH. At 20 degrees and pH 4 the solution active enzyme is Only at pure strength 16% max.

SHOE0007 (author)2017-02-01

This solution of enzymes prevents growth of plants safely.

SHOE0007 (author)2017-01-31

In school the Plamsa is used to peirce cell wall of bacteria and fungi. I have to do a trial and error results to get the enzyme out.

SHOE0007 (author)2017-01-31

I am attempting again to plasma enhance the effects of mold and generate plasma that may (Key word) penetrate the cell wall structure of the cell. 12 kV 30 ma at 1 degree gives roughly 85 Amps. Here are some images of prep work.

SHOE0007 (author)2016-11-26

What you are seeing is plasma.

SHOE0007 (author)2016-11-26

Here are a few prototypes of using high voltage with PI inside a aluminum foil which generates a plasma. It is important that the PI be completely dry with 12,000 volts 30 ma.

SHOE0007 (author)2016-11-07

Here are some images of results of grtowing pencillium and procedures to help

SHOE0007 (author)2016-11-06

Here is a project on a natural herbicide although it did not work maybe it could work on a larger scale and with better centrifuges and chemicals.

Using mold (PI) with soap (Ammonia lauryl sulfate and Ammonia lauryl sulfite.

Intro: Here an potential type of herbicide made from activated Pectinase enzyme from

Pencillium I. Growing mold and letting 30 g of mold dust collect onto a solution of soap

and attempting to isolate Pectinase is possible.

Purification with a centrifuge at speeds of 105,000 rotations a minute and lower speeds of 35,000

rpm Total with fridge exposure overnight as well as purifying with a 0.1 micron antimicrobal and antifungal filter including

spores is essential.

Clover with soil (regular type) when a purified solution with water and others with ammonia 0.166 moles per L has lead to slowing down the cover.

Purpose: The purpose is to make a natural herbicide with Pectinase from PI.


Theory: Soap containing digestive surfacants including ammonia lauryl sulfate with high speed centrifugation may be able to purify and extract Pectinase

in sufficient qualities. Centrifuging and chemical cell wall digestion with special soap could result in release of enzyme Pectinase.


Lactose milk protein

Cocoa powder



Soap containing Ammonium lauryl sulfate or equiv

Tap water

Cocoa pudding

Ammonia hydroxide 1 Molar


Pencillium I


Clover seeds

100 mw purple laser (line) 405 nm



Hot plate and stirrer

500 ml flask ( to put agar cocoa plates)

Alochol burner


Growing the mold on cocoa pudding mixture. Water is added to a concentrated pudding cocoa with milk protein to grow penicillium I fungi. Unlike bacteria spores

of PI require up to 3 weeks with normal humidity. A stock solution of PI is made by exposing cocoa agar glucose plates in the air for 5 days. Naturally there in trace

amounts. Once mold grows on plates it takes a few months to convert it into a powder.

Warning: Although PI is non pathogenic/non-toxic, large doses in some individuals may lead to allergies. Always due this outside and wear a gas mask or a N95 mask to protect yourself

from the spores.

Extracting the mold. In about 3 weeks to a month the mold will turn into a hard rock like substance. Outside with N95 mask, gloves, safety goggles, apron hit the mold species gently

with a hammer. You want to min the amount of mold spores that are released and allow for the chunks of mold to be placed in 100 ml of tap water with the desired soap 5 g.

In a few days the mold will slowly convert from spores back into the active PI. Soap with ALS should attack the cell structure over a long period of time. Remeber that it is difficult

and if the solution sits for many days then filtering and dilution must be done. This is because too much junk in the solution to filter with regular filter paper and will most likely

clog the filter.

In 2.0 ml centriuge tube (while wearing PPE) pipette 1.5 ml of sample and balance the centrifuge as according. For more info look up how to balance and set up the rotar of a centrifuge.

Using a clock time 5 minutes max (mine makes weird sound past 7 minutes). 8 tubes with PI solution will be centrifuged for a total of 35,000 rpm T *3.

with the sample centrifuge and without distrubing the pellet decant the tubes into fresh new tubes and place them (closed)in a beaker and store at 4-8 degrees C.

Making the Pectin pectinase gel.

Sodium fluorescin 1 ml in 100 ml tap water plus 5 g agar and 5 g Pectin (with acids) is placed in a flask (500 ml) and heated until it boils about 33 ml of the solution once it boils down to

80 degrees (after reaching 100 degrees C) are powered into polypropylene cups and placed into the fridge for 3 days (aprox) or until the solution gels up.

Activating the laser. A 405 nm line laser 100 mw from e-bay was used. Danger: Never look into the beam or the reflected beam to aviod retina damage especially at 50 mw or greater.

When the laser is fired across the plate you can see a green bubble like shape appearing. I think that this is the pectinase enzyme breaking down the gel. This took 5 hours to appear.

Growing the clover: Seeds of clover are exposed to several soil samples and exposed to tap water and some of the enzyme trial herbicide. The addition to 1.5 ml sample to get 0.166 moles Ammonia hydroxide

may help activate the enzyme.


The difficult process of pectinase is the fact that it is difficult to extract without harsh chemicals. A high concentration 2% bleach or sodium dichloroisocyanurate is needed to extract or attack the

cell wall and when combined with ammonium lauryl sulfate then chlorine gas is released which will attack the polypropylene centrifuge tubes. Another possiblity is to use high voltage with dried aluminum foil

to control burn the spores to allow chemicals to pentirate afterwords but this is quite dangerous.

SHOE0007 (author)2016-11-01

What about Poison Ivy? it has tough roots and is highly resistant to many herbicides like Round Up, etc.

SHOE0007 (author)2016-11-01

Filtering with a special type of micron filter that blocks bacteria (0.1 micron filter) from Sawyer is also essential to attempt to remove any left over spores.

SHOE0007 (author)2016-11-01

Have you heard of using natural enzymes from Pencillium I (a plant pathogen) and purifiying the enzyme called Pectinase. The mold has a tough cell wall that requires centrifuging and spinning

Please see the link if you are interested.

Ghostryder_ca (author)2016-06-19

I just use straight vinegar. Most of the "eco" herbicides I see on the store shelves are just 7% acetic acid. Pickling vinegar is 7% acetic acid. And costs less for a 4 litre jug than the 750 ml "eco" herbicides. Seems to work best when weeds are young. Larger established weeds seem to be more resilient.

retihiamatikei.cribb (author)2015-04-17

Hot water does a good job, a little expensive but safe for the grand and great grand children. I wonder about how it might affect the worms though so try to not pour too long!

Computothought (author)2014-05-25

Looks a lot like the idea behind my instructable.

racoontnn (author)2013-02-23

It is hard to call this part of biodegradable as salt from the soil nowhere to stay. Yes, this line-up will destroy the weeds, but on this earth a little that will grow.

blkhawk (author)racoontnn2013-02-23

You are technically right that salt is not biodegradable. This issue has been discussed many times. However no proof has been presented that a little amount of salt would make your yard a huge brown spot. In every discussion that I have had on this issue no irrefutable evidence exists that this salt will permanently damage your yard or the environment.

racoontnn (author)blkhawk2013-02-23

Dear Sir, I just wanted to say that the salt remains in the soil, and I agree with you that it does not do any harm. I agree with you, and when the snow melts, I will process your staff my site. I think the best place for treatment will be the place where it grows weeds and crop plants do not grow.

blkhawk (author)racoontnn2013-02-23

Salt can be found naturally in the soil at different concentrations. Sometimes salt is added to the soil to help treat chlorosis. Salt will not remain on the ground forever. When dissolved in water, the sodium chloride framework disintegrates as the Na+ and Cl- ions become surrounded by the polar water molecules, thus combining with other elements to form other compounds.

racoontnn (author)blkhawk2013-02-23

Dear Sir.
Saline, or saline soils are those soils that contain a variety of easily soluble salts in an amount clearly harmful to the normal development of the crops. Almost to salt marshes include soils with soluble salt content of more than 1%. Your composition biodegradable herbicide could never bring so much salt in the soil. Consequently, for the cultural soil it is harmless.

HowToLou (author)2012-12-09

Just adding my experience here. I had a house with a paver patio with a terrible weeds-in-cracks problem. A Round-Up treatment would kill weeds, but last for only a week or two. I started pouring a whole cardboard can of salt on the patio and sweeping it into the cracks. Sprinkle a little water or rain on it and my pavers would stay clear for at least two months at a time. To help alleviate salt-fear, I will say that after two months, the vegetation was back, as strong as ever. Also, the plant beds, adjacent to the patio, grew just as well as the ones further away. -Lou

Yard Sale Dale (author)2012-08-03

I live in a house with vinyl siding and I don't like weedeating around it. I also don't like plucking weeds from driveways. I'll try something like this. Probably I'll make a combo of pool salt and cheap sand, and pour it around the house to prevent weeds etc from growing there. I don't think a guy spraying some salt water from a spray bottle is anything of a disaster like some wall-of-text-posters here are crying about. A lot of commercial herbicides (used on farms no less) have instructions which call for them to be measured out in sprayers and mixed with maybe 20-50 parts diesel or fryer fat. That will probably keep the trolls up at night. hahaha

blkhawk (author)Yard Sale Dale2012-08-03

Trolls live with their computers under bridges! :-)

tryb01 (author)2012-07-31

Wow, you have started quite a controversy with this salt mixture. You might not have had as visceral of a response if you had suggested using radioactive waste.
Like most of the projects posted on this site your results will vary.
I am not in favor of polluting ground water. Using Roundup & similar commercial products are of real concern. Those products contain dozens of long acting chemicals that should not be in the hands of the general public. Salt is a pretty basic chemical that should not cause birth defects or rearrange your genes in surprising or unpleasant ways. Of course, anything can be toxic in large enough quantities. Even H20 will kill many living things if used improperly.
If you don't like the idea of putting a few spoonfuls of salt on your weeds then don't do it. I am not always right. I am open to learning new things but I don't think small amount of salt will do any great or long lasting damage, esp when compared to all the other garbage flowing into the ground, streams, & oceans.

blkhawk (author)tryb012012-07-31

Thank you! I agree with you. Like everything else in life, too much of a good thing is never a good thing.

andyk75 (author)2012-07-20

Please think it over and remove this instructable!!
This is no alternative to herbicide! It will only pollute the groundwater with a big amount of salt! And this is not bio-degradable. It will stay there or end up in a river!

I can speak for Germany, where using kitchen-salt this way is forbidden!
Nearly nobody knows its forbidden and people try to tell you it is natural and safe, but it is NOT! It harms our water and the fishes in the rivers!

So please don't do this at home or anywhere else!

marcintosh (author)andyk752012-07-22

This is no alternative to herbicide!

Yes it is!

relax, everything's going to be alright.  Pro-Tip; don't drink so much Red Bull and post.  

josephlebold (author)marcintosh2012-07-23

Really the title is misleading. Salt is not biodegradable. Even though salt is needed for most life processes it kills or stunts when levels are high. There is a reason why they recommend not drinking ocean water.
Problem with using it on a driveway is that it doesn't stay there, it washes down into the ground to our drinking may take 100 years to get there but think what 100 years worth of salt will do once it gets there, and it will take about as long for it to all work through the system.

The only totally environmentally friendly weed control is actually manually pulling and digging them out. Bonus exercises/yoga/whatever. People are so freaking lazy nowadays.

blkhawk (author)josephlebold2012-07-26
According to the website How Stuff Works the reason why we should not drink ocean water:

Unless you drink a lot of freshwater, the body's regulatory mechanism in this situation is potentially fatal. With seawater, the change in sodium concentration outside our cells is the main culprit. In order to regain an isotonic state, a must for cell survival, the body attempts to eliminate the excess sodium from its extracellular fluids. It secretes urine. However, human kidneys can only produce urine that's slightly less salty than saltwater. So, in order to remove the extreme amount of sodium taken in by saltwater, we urinate more water than we actually drank. And dehydration sets in.


marcintosh (author)blkhawk2012-07-27

This salt controversy is still raging eh? 

Nothing else to do I suppose - Any new viewpoints? (glances over comments) nope - same old same old-

Move on - you guys need a job - go volunteer somewhere -  Make it a better world - stop squabbling over a tablespoon of salt.  Move out of your parents basement.
"This is why you can't have nice things"

blkhawk (author)marcintosh2012-07-27

To show you how easy is to spread rumors and fear, check this website, About all the dangers of "dihydrogen monoxide" (another name for water).

kimvellore (author)josephlebold2012-07-25

Just do it in the evening, don't want you to sweat it and add more salt...

josephlebold (author)kimvellore2012-07-25

Good point.

arthur verburg (author)andyk752012-07-23

the amounts used by this, although not bio-degradable herbicide, don't reach levels of toxicity as prohibited by law, like those levels used to melt snow.
I've tried this herbicide successfully ( used 1 l. vinager, 1 coffeecup (0,3 l) of salt and one coffeecup of dishwashing detergent). Get's well on cracks or fissures on sidewalk and so on, yet on garden use not so good. because you'll need amounts that will harm your plants. There are herbs who resist.
by the way, nice instructable blackhawk.

blkhawk (author)arthur verburg2012-07-23

Thank you!

djimdy (author)andyk752012-07-22

Pouring heaps of salt on your lawn is not a good idea. But that is not what this poster is saying. Scolding comments to the contrary show innumeracy at its best.

A truly civil society and its members should look sensibly at what they do and not repeat mantras of FUDs without thinking.

The poster is saying 12 ounces of salt for 1 gallon of liquid. That's 12 OUNCES.

Think what a 5lb bag of sugar looks like. That's 80 ounces. Now mix that with 6.6 GALLONS of vinegar. That's a lot, right? Would you be using this all at once? In one spot? Or even for your ENTIRE YARD? Unless your yard is several acres, I highly doubt it. Can you imagine using that much Round-Up on your yard?

Once again, that is with a SINGLE 5lb bag.

Your neighbor's dog likely pisses more weed-killing salt on your lawn every single day. Over the course of a decade, do you really believe that that salt will overpower the thousands of tons of dirt between your lawn and the water table? Not. Bloody. Likely. Otherwise, there would be nothing but barren wasteland for miles and miles from the beach's edge.

Please, people, think.

andyk75 (author)djimdy2012-07-22

Hi djimdy,
didn't want to sound rude. And indeed you are right. 12 ounces per gallon is not much. But it won't help, it is just as if you didn't use it. Look at the post of chabias.

Why I reacted this way was:
I did several studies about groundwater and know the problem with salt in groundwater. Not always anthropogenic, but very often.
And on the other hand: I have a small garden by my own, and I saw a lot of neighbours pave their walk-way with salt each summer to eliminate the weed. It did work for up to three month maximum! And they used a real lot of salt, like 500g per square-meter or so.
Don't know with how much they started out, but if a little bit doesn't help, let's try more and more and more and more...

boiling water, vinegar, flame thrower, a knife and sweat, that all is o.k. and works for some time, but please omit the salt !!!


djimdy (author)andyk752012-07-23

Hi Andreas,
Your anecdote is much more informative this time around and helps a great deal to explain why such laws may be in place: because there are plenty of fools out there who tend to overdo things exactly as you said.

Salt apparently restricts water uptake by plants, so perhaps the addition of vinegar at the same time (as opposed to separately) really does help.
What would be nice is pictures showing results, not just talk (one way or the other).


blkhawk (author)andyk752012-07-22
I understand and share your concern for the environment. Regarding the impact that salt poses to the environment, this information shows that there are other sources than road deicing with salt that affects the environment:

Chlorides are released naturally into the environment through the weathering of chloride-containing rocks and minerals. The seas and oceans contain vast amounts of dissolved chloride. Chloride also enters the atmosphere naturally as a result of volcanic activity, forest fires and sea spray. Coal also contains significant amounts of chlorine that is released into the atmosphere as hydrogen chloride during combustion, where it contributes to acid rain. Coal combustion for power generation is one of the biggest industrial sources of chloride release to the atmosphere. However this is falling as a result of the declining use of coal for power generation and the installation of emission control equipment at major power stations. Other sources of chloride release into the environment are agricultural runoff; wastewater from various food and chemical industries; consumer water softening; pool salts; effluent wastewater from water treatment facilities and; road deicing operations.
Salt Institute

Like it was commented, the small amount of salt that you will use in this project will not affect the environment. You will only apply this concoction on pavement cracks. Constant freezing, thawing and rain will dilute the salt. And this herbicide is not intended to be used constantly, depending where you live you may not have to use it more than once each season. I hope that this will help with your concerns.

LordBthry (author)andyk752012-07-22

I live close to the German border (North-east part of the Netherlands) and I have never heard that using salt is forbidden in Germany.

Great instructable and I will surely try it. (We get free salt in the winter so I don't even have to buy salt!)

mgalyean (author)andyk752012-07-22

Agreed. Pouring boiling hot water over the weeds will set them back a lot. Or better yet, judicious use of a broad spectrum weed killer that kills to the root followed by patching the cracks in the pavement with something that bonds to the existing pavement and seals against water intrusion as much as possible. The weeds will still come back eventually but have a tougher go.

marc.cryan (author)andyk752012-07-20

Yeah - We pave the streets with salt all winter. Sometimes there are warnings not to drink the tap water because of the high sodium content.

We also, dump herbicides into lakes to kill plants that are overgrown from fertilizer sprayed on lawns.

You can't eat the fish anyway because of the heavy metals.

I am in the NorthEast (in the USA). There are more and less polluted areas, it varies by state.

We also use remote control planes to blow people up in other countries -- but that is off topic.

stixnstones (author)2012-07-23

I think the whole point here is to minimize our impact on our environment in every way possible. Salt and Vinegar is the lesser of the two evils if Roundup is the other evil. Better yet you can obtain a higher strength of vinegar online which will even kill bamboo! Use sparingl

There are so many great alternatives to using Roundup which is deadly to frogs and toads and I am sure has effects on us we do not yet know.

Several of my favs are a tea kettle of boiling water poured on the cracks in the sidewalk to cook out the unwanted plants. Remember new seeds germinate all the time so a regular regimen is best.

Think about smothering the unwanted, mulches work, wet newspaper works, tarps work , it just depends on the size of the area you are trying to eliminate unwanted plants from. A black tarp in the sun covering your paver patio for the morning while you run errands will do the job and is a heck of alot cheaper and safe for the kids and critters.

Also do not let weeds go to seed. Pull them, cut them, douse with boiling water. Eventually you will see less and less intruders.

Another fav method to rid the unwanted is with a propane flame weeder (not recommended in dry fire prone areas). There's something quite satisfying with selectively frying a persistent deeply rooted weed!

lbrewer42 (author)2012-07-22

I used to live near Erie, PA. The soil there was different than where I know live in PA (Gettysburg area). In Northern PA I would apply this mixture once at the beginning of summer, the weeds died off just as fast as using the commercial weed killer "Roundup," and I literally had no weed problems the entire summer (3-4 months for that area!).

When i moved to where I am now, I mixed this stuff up and applied it. The weeds came back within a month. So I am guessing the makeup of the soil in this area (a lot more limestone) is such that the plants growing are more resistant to the vinegar/salt combination.

In fact I have noticed that commercial products have more trouble down here as well :( I applied some "Ortho" weedkiller a month ago and need to do it again!

As to the danger of salt being in the environment - whoever puts stock in this theory has never been in places with winters like NW PA. Salt is constantly put on the roads (and has been for a very, very long time) for up to 5-6 months per year to combat ice and snow conditions. There is no problem with it in the water table after countless tons have been put into the environment over the years. And I also noticed I never had to worry or fuss about a garden in NW PA like I do here. Up there, things just grew. Where I am now, this kind of soil makes gardening an art form to become successful at it.

Dale_D (author)lbrewer422012-07-22

One difference between Erie and Gettysburg is the fact that eastern PA in general has been farmed heavily for a few hundred years (about 300 or so). Many German and Dutch families settled here early on, and most were farmers. The soil has probably been depleted more here (I'm in New Cumberland, about 35 to 40 miles NNE of you, and used to live in Schuylkill Co. ... farmland and coal mining region).

P.S. Welcome to Eastern PA!

lbrewer42 (author)Dale_D2012-07-23

Now THAT makes a lot of sense. I know Erie was nowhere near as settled as this area. And even to this day people in Erie want to move b/c of the Alaska-like climate the Lake causes (which I dearly miss - I know, I am crazy!).

Thanks for the welcome - this is a pretty area, and the people sure are nice. I just have a lot to learn about growing a garden down here! I have a 4-square system set up and my plants grow but produce no fruit! And even this year, the tomato plants seem to have stalled in their height and no sign of blossoms so far?!

BTW - actually I'm in Chambersburg but did not figure too many people would know where that was.

Ohenrio (author)2012-07-23

In my country (Britain, France) we use algae collected at the coast, the sea, and we put them sue the herbs in the fall, effects and ecologist for our Planet!

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