This is a confusing topic and a great deal of mis-information is out there about organic weed control. So let’s start with the basics.
Weeds typically show up in your yard because by any number of means weed seed ended up in your yard. Maybe birds, mostly the wind.
Weed seeds need just a few things to germinate and become a prolific pest in your yard. They need moisture, they need soil that is at least fertile enough to support them and it seems that weeds are not that fussy. And weeds need sunlight.
We can’t control the rain, more than likely we want our soil in our yard or gardens to be more fertile, not less fertile so we have little control over that except to make the soil more fertile.
So that leaves us sunlight. Ahhhaaa! We can control sunlight!
That’s what we’ll do, we’ll take away the sunlight!
Controlling sunlight is probably easiest done by mulching our beds with some kind of shredded bark mulch. Usually all that is required is 2″ to 3″ of bark mulch to do a nice job of controlling weeds. However, nothing is fool proof and gardening will always require a watchful eye and some effort.
That could mean sweat on your brow and dirt under your fingernails.
Warning, warning, warning!
Please, please, please be careful how you use weed control fabrics in your gardens. Do they work? Not really. Usually quite poorly. The weeds will grow right through them and almost permanently attach the weed barrier fabric to the ground making removing it the worst job ever.
How do I know that? I spent years and years re-landscaping homes and we encountered miles of this stuff and I can assure you, it does not work in most situations.
There are two ways to look at this.
- You can say that Mike is full of crap, he has no idea what he’s talking about, my landscaper said weed control fabrics are a good idea. And . . . it says right on the packaging that they work.
- Or you can say, “Gee, Mike hasn’t lead me down the wrong path yet and if he really has been working in the dirt, on his hands and knees since the mid 1960’s , maybe he does know what he is talking about. And . . . he has nothing to gain or lose whether or not I use weed barrier fabric or not. Mike has no skin in the game either way!
- And you can see some real life examples of me and my life dealing with weed barrier fabric right here.
Does Mike ever use Weed Barrier Fabric?
He does! “The lyin little cheat uses it all the time but tells us not to! I knew I couldn’t trust him!”
Yes, I do use weed barrier fabric. I actually have miles of weed barrier fabric in my nursery. We use a really high grade, heavy duty fabric on the ground and we place our nursery containers on top of it and it does a pretty good job of controlling the weeds, as long as we do our job and deal with any weeds that show up, because yes, they grow right through the stuff.
But here’s the big take away!
I never ever, ever put anything over the fabric like soil, mulch or gravel. Because I know that doing so will encourage weed growth like nobody’s business! And I also know that sooner or later I will have to pick up that weed barrier to either replace it or return those areas to their natural state.
It would be an absolute crime to let the weeds grow up through that stuff and then leave it in place.
If You Watch the Movie on this Page you will see how we use weed barrier fabric and how easily the weeds grow right through it. You will also see how my neighbor Richard uses it in his veggie garden but pulls it up each year.
So there you have it! Weed barrier fabric used correctly and incorrectly.
What other organic weed control techniques work?
Newspaper and cardboard work great and controlling weeds and grass and are 100% organic.
A while back I did a pretty good article on this topic, you can read that here.
Tilling or cultivating.
Those things work incredibly well and this is why. If you keep the soil worked in your garden, in between the plants, you can disrupt and eliminate weeds right after or just as they are about to germinate.
In order for weeds to get a foot hold, they need a little time to themselves. If you work the soil once a week, or every ten to fourteen days you should be able to effectively keep weeds at bay. Oh you’ll get weeds alright, it only takes a few days for weeds to germinate and start to grow. But if you disturb their happy little playground just as they are getting started you will end their lives immediately and interrupt other weeds that are just emerging from that germination stage.
Tilling and or cultivating work because . . .
- You disturb weed seeds that are just about to germinate and therefore eliminate them.
- You up root and expose weeds that are post germination exposing their roots to the sun and wind, drying them out and killing them.
But these strategies are only effective if you are diligent and keep at it. If you take a few weeks off, all is lost and you have a lot of work on your hands to get the garden back to a state where tilling and cultivating can once again be effective.
What about vinegar as a weed killer?
Yep. It works. There are a lot of recipes floating around on the Internet and vinegar is being touted as the best weed control product ever! Works almost immediately and lasts forever!
That’s a half truth and a half lie.
Vinegar does work almost immediately, or at least within a matter of hours you can see some results. But here are some things you should know . . .
- It’s pretty effective on broad leaf weeds but not nearly as effective on any kind of grass or grass like weed.
- It does not kill the roots of the weed, just the top part that you can see and spray. The weeds will come back from the roots.
- Regular household vinegar is only about a 5% solution and that really is not enough to be effective.
- You need horticultural vinegar. That’s more like a 20% concentrate and considered by some to be dangerous. This Article Addresses the Dangers of Vinegar in the Garden.
And there you have it! Some common sense approaches to organic weed control.
Questions, comments, mean things to say? Post them below and I will respond.
Mike, right on: I have used Cardboard for years or newspaper 12 pages thick.
I continually tell customers the folly of using Black Plastic. it just sets up a separate echo system under it ,You pull it up ( with much work) and all the roots of the weeds is right there on top of the ground.
You are correct, and you did mention Cardboard several times..
Mulch over the cardboard is a must, it adds nutrients to the soil as the cardboard decomposes.
Thanks so much for sharing all your knowledge and experience. I always find something new and helpful , and appreciate the time you put in to do this. Merry Christmas !
Thank you Lorraine!
How can I keep weeds down on a steep hill? Wild blackberries have taken over it. I want to landscape it, but don’t want to keep dealing with the blackberries.
Sherri,
Remove all the plant growth on the hill and keep it cultivated every 7 to 10 days for a period of many weeks when it’s warm out. That will get rid of all the active roots and many of the active seeds in the soil. Then mulch with at least 3″ of mulch. Put down cardboard before you mulch. And from there keep it weeded on a regular basis.
For long lasting weed control, apply elemental sulphur at a rate of about 2-3 pounds per square yard. This lasts for years. Using powdered sulfur gives a shorter lasting effect, but you can uses 1/10 as much.
It works by slowly converting to sulfuric acid, and lowers the soil pH to 3-4. I use this along the edges of beds.
Sulfur is cheap at any ag supply store.
***
While a tiger torch/flame weeder works, you go through a lot of propane. Ideally you want to just heat the leaves enough to wilt them. Best if you can apply cold steam. This requires a modification of your torch to inject a coarse mist of water into the combustion air. The goal is to have the last of the flame evaporate the last of the water. If you can enclose the output, you can have a portable high efficiency flame weeder. Either a cone on the torch wand, with notches at the bottom to let the spent steam out, or a wheeled version made from an old lawn mower chassis.
i have used 6 mil black plastic to prevent weed growth.I cut an X in the plastic and put my plants in it.I then cover it with mulch.For large permanent plants,like shrubs, I plant them as usual, but with a larger X to allow for growth through the plastic,then puncture the plastic all around with a pitch fork for drainage.,Been using this method for years.The only weeds that occur are shallow,only reaching the plastic through the mulch, about 2 inches.I use crushed brick for mulch,around borders and it looks good and never has to be replaced.
I just want to remark on this information and the followers.
Great advice and a priceless education when many chime in.
United we stand but divided we fall.
Happy Thanksgiving to all and ride or die.
Tilling kills vital microorganisms in the soil, among other damaging things. You had 3 chances to name the best organic weed control and still couldn’t guess MULCH? You can organically kill weeds by mulching heavily. Cardboard (as others mentioned), leaves, grass clippings, hay/straw, and wood chips all make excellent mulch. Chop and drop works great too! Just cut the weeds at ground level and leave them there to become mulch.
If you are building the soil with decomposing mulches you don’t need to till OR change rows every year OR pull weeds. You don’t need to water as often. It’s the simplest, easiest, and usually low cost weed control method.
Bruce,
I thought for sure I mentioned mulching in the article but maybe not. But I did update the article with a link to an article that I did about cardboard, newspaper and mulch. You can see that article here; https://mikesbackyardnursery.com/2014/08/step-step-guide-making-weed-free-flower-perennial-garden/
You would need to do shallow tilling for this sort of weed control. Use a stirrup hoe, or a diamond hoe. These run on/just under the the surface.
Another option is a sweep dultivator on a wheel hoe, with a depth gauge behind it. This allows you to quickly do the aisle in a garden, again, not disturbing more than the top bit of soil.
Bruce, i have started mulching with old hay and leaves and I have goats and rabbits and have been putting their droppings in the area also. I don’t plan to till , just pull back enough mulch to plant seeds. Hoping this works. I read about this in a book called GARDENING WITHOUT WORK by Ruth Stout. Don’t believe the title because there is always work with a vegetable garden.
Thank you for this article, Mike! Others have already mentioned cardboard covered with mulch, my favorite solution, so I won’t repeat that. But here are a couple of ideas I am working on:
1. I just bought a wire brush specifically to get weeds out of cracks in patios and sidewalks. I am looking forward to using it soon at a client’s home.
2. I also bring a hot water jug outside when I am gardening, fill it up, and when it boils, pour it on the cracks in the paving. That works too. I just keep refilling it and kill weeds in between other gardening tasks.
3. A big problem where I live is that people have gravel driveways, and the weeds love it! In the past, folks used glyphosate (Roundup) herbicides, but now they are getting away from that. What to do? I am going to experiment with a heavy gray canvas tarp covered lightly with pea gravel, for camouflage, that can be put down for a few weeks, and moved to different areas of the driveway. Plastic tarps would be too shiny, but this canvas one may do the trick. I wouldn’t put it down over winter, just in spring and summer. Anyone tried anything like this for their gravel driveways?
Diane,
In the driveway you might consider a flame thrower type of torch, you can buy them at farm supply stores.
Thank you for all the information you constantly give to us.
You are as blessing to many and I pray you and yours had a blessed Thanksgiving!!
Thank you Patty, I appreciate that.
So you could not provide an effective organic weed control- just a wastage of time reading your article:(
Pretty sure I covered a few effective techniques for organic weed control. Just no silver bullet.
FYI: I live just north of Cincinnati , OH and find household vinegar very effective weed control around the base of trees & postsi, Does not kill roots but continual killing of top growths will cause roots to decline then die. Vinegar knocks down the vegetation for more than a week and spraying mistakes are basically harmless – good for areas near your property;line; other wise, complete herbicides.
Jim,
Thanks for your input!
I missed it.
Yes Mike, you did! I like mulch, we use woodchips adding a layer of cardboard for bad boys like weedy artemesia. I completely agree on Landscape fabric, having done cleanups and new beds for clients! Vinegar & torching are ok, Thanks for this article!
I’ve been using cardboard in my garden and it seems to work well. I put compost down first, then plant my transplants or seeds, then I place the cardboard in between the rows or sections, and then I place a little more compost on top of the cardboard to keep the wind from blowing it around. I’m not sure if there are any issues with the ink used that’s printed on the cardboard. The cardboard breaks down completely by the end of the season and I repeat the process in the spring. It’s been a good way to re-purpose all of those Amazon boxes that I get in the mail.
Susan,
Cardboard is a great idea and the ink should be soy based and harmless. I forget to mention this in the article.
You mean all those Amazon boxes that get delivered by overworked underpaid amazon dsp drivers! ; ) No chemicals, Recycle, repurpose is the way!
We bought a product from the UK, Barrier H to kill ragwort. The cost is over a hundred dollars when you add in shipping. We had been fighting it for a few years in the horse’s pastures. We finally have it under control by buying the main ingredient separately. Barrier H is about 23% Citronella oil and an emulsifier. It is easy to buy the Citronella oil and make your own. We use about 4-5% Dawn soap, 28% Citronella oil and the balance is water. Once the Ragwort has been killed back, we mow the area with the mulching mower and bagger. Then we burn the results. (The horses won’t eat the Ragwort until it is killed back by frost. Over time it will destroy the horses’ livers.)
The mixture is also excellent for killing pigweed, which can even kill horses if they eat it.
It is an excellent fast-acting plant killer.
Thanks Joan, great info!
I do have a permanent organic weed killer which really works great.
Ingredients:
• 4 cups apple cider vinegar
• ½ cup of salt
• 1 tsp liquid dish soap
Supplies:
• Large spray bottle
• Large bowl or bucket for mixing
• Wooden spoon
• Funnel
Instructions:
1. Measure the apple cider vinegar and salt in a large bowl or bucket.
2. Mix ingredients together with the wooden spoon until salt completely dissolves.
3. Add the dish soap to the mixture and stir to combine.
4. Fill the spray bottle with the weed killer, using a funnel.
5. Soak the weeds with the solution on a dry, sunny day. Coat all surfaces well with the spray.
Any plants soaked with the ACV weed killer will die within several days. They won’t return, and nothing else will ever grow in their place. So, make sure you only use this where you want nothing to grow like sidewalks, walkways, driveway and patio stones.
Wouldn’t distilled white vinegar be more economical. The recipe I use doesn’t all for horticulture grade and it works well, however, the spray bottle doesn’t hold up well. Perhaps the salt clogs it?
Beth,
That’s possible. I would probably pay to flush the spray bottle after each use.
Salt probably corrodes the spring mechanism too.
I use an old squirt bottle to hold my mix – one that held dish soap – for my salt and white vinegar (household) weed killer.
I’ll pull the weed body, then squirt around the base and spine of thistles, swine weed, etc. It’s a 2 – 3 year task to get a patch of weeds fully killed (clay soil), but it does work over time. And when I do it in early spring, this will keep the weeds from coming back until next year.
This is great always enjoy reading your information from alabama
Thank you David.
Tjis great
I love your emails and videos… Far more entertaining and informative than watching television (and no scandals or politics) thanks for what you do
We put down cardboard ( a couple of layers ) then cover it with 4-6” either compost, mulch or both. But know sooner or later you will have to do it again, for us it was 2 years. But, no weeds.
Scott,
Cardboard is great and I should have mentioned that in the article. I’ve written about it in the past.
What’s the best thing to use under mulch and rocks
Louis,
Cardboard. Unlike weed barrier fabric it eventually goes away and improves the soil. I have some stone around my house with nothing under it. I just control the weeds.
How do i control yuccas? i have about 20 acres of them i also have horses, livestock is there anything that i can use so i wont hurt my animals?
Jackie,
I think the short answer is nothing. The roots go too deep. Continual cultivation over time would do the trick. See this; https://mikesbackyardnursery.com/2019/03/how-to-get-rid-of-yucca/
I use feed sacks in my garden. I only have a 20′ x 40′ garden. Come spring they are pretty much gone. What is left is deteriorated and easily tills into the ground. Only drawback are the strings hold up and get rapped around the tines.
Sooo… remove the strings first?
I wanted to kill everything in a part of my garden to start wildflower meadow and they really are sensitive to herbicide so I put thick cardboard down overlapping the entire area in late summer to remove in spring hoping I have killed everything, will I have accomplished that?
Jill,
You’ve probably eliminated the weeds, but seeds will always be an issue. I wrote this along time ago, but you should check it out; http://freeplants.com/free-article-wildflowers.htm
Black plastic might get hot enough to kill the weeds and seeds (for now) but they will find their way in of course.
Have you tried corn gluten as a pre emergent weed control? Does it work?
Sue,
Allegedly it works, but you have to use what I considered a ridiculous amount of it. With a suggested rate of 20lbs per 1,000 square feet. That’s a 10 by 100 area. See this; https://extension.oregonstate.edu/news/corn-gluten-meal-did-not-prevent-weeds-germinating-osu-study
Good job Mike
Your hundred percent right on that fabric don’t work for most application
Thanks
Thanks Eric.