Killing weeds with tarps vs. landscape fabric

Many urban farms are starting to kill weeds with tarps. I've done it myself; it really does kill weeds very well, and encourages the breakdown of organic matter, leaving a nice clean seedbed.

However, water pooled on top of the tarps. This was potential mosquito habitat. Also, in my dry climate, I'd really prefer the water to go into the soil! And small critters might take up residence under a tarp; I imagine that the more porous material would be less attractive to them, since it would let water in.

So, has anyone tried to use heavy duty landscape fabric or similar ground covers? Do they kill weeds like tarps do? Or is the impermeable nature of the tarps important? How would the fabric hold up?

I toured a wildflower breeding farm which used super heavy-duty landscape fabric that stayed in place for years. Holes were punched in the fabric at appropriate spacing for the species being grown. It kept the weeds down very well, and because it was fabric, water flowed right through.

When I was killing my front lawn, I used both. I started out with landscape fabric but it was much more expensive, that was my main reason to finish with black plastic. Both worked, and we don't get much rain so puddling wasn't an issue. Both will break down, not in the composting sense, but they will break apart when trying to remove if left too long, which is a hassle.

I have talked about my method several times on the forums but bottom line is I use black rubber roofing material that is reclaimed from commercial building sites.  It doesn't break down in UV light and is super strong.  You do get water puddles.  Any type of material I've ever used that water can get thru also lets weeds grow thru it and it becomes a nightmare to remove.  I would much rather deal with puddles.  I id change the size of the sheets I use.  I used to use the biggest pieces possible.  Very large pieces are very heavy and hard to move, so now I use pieces cut in 4 or 5 foot strips.  It works better for me because they are easier to move, and I can leave a 4 or 5 foot DMZ around my gardens to keep quack grass from encroaching on spaces I have already killed off.  The strips also let a lot more of the water run off and get down between the strips of rubber so there is less puddling.  You will still have some, but mosquitoes take a while to hatch and it's not hard to take a few minutes on the weekend and tilt the rubber enough to get the water off.

Definitely good point.  UV breaks down tarps.  We use the black woven AG stuff for 7 to 10 years before replacing in a high UV country.

Also they are thicker and black, kills them faster . But tarps make great temp fixes


The roofing material, is it safe?  Is there anything in there that is leaching?

For me, permaculture is defined as permanent long term agriculture. A system of agriculture that works in co-operation with Nature and Earth. I know we humans like easy solutions, ...but. I find it hard to understand why anyone who claims to hold permaculture beliefs would put anything plastic or chemical or artificial into or on the Earth. It may be easy, but sooner or later, all that chemical garbage will breakdown and enter your soil (or if you remove it, the soil of a landfill). I thought we were trying to do better.  

If looking for a more natural approach try sheet or lasagna mulching. This technique uses alternating layers of cardboard, newspaper, grass clippings, wood chips etc. to smother the weeds. It requires more work and resources however there never seems to be a shortage of newspaper, cardboard, clippings and the likes around here. For really tough invasive species I use this technique along with added weed fabric and pallets for more weight to help smother them out with success.

Jim Fry wrote:I find it hard to understand why anyone

 

Jim Fry wrote:would put anything plastic or chemical or artificial into or on the Earth. It may be easy, but sooner or later, all that chemical garbage will breakdown and enter your soil (or if you remove it, the soil of a landfill). I thought we were trying to do better.  

In the cases of roofing material and silage tarps, they have gone through one use and are being diverted temporarily from the waste stream for another beneficial use.  If they are leaching into your soil, then that would be a valid reason to not upcycle them.  As long as they do some good for you and then re-enter the waste stream correctly, I don't see a problem with it.

"As long as they do some good for you and then re-enter the waste stream correctly, I don't see a problem with it."

Whole heartedly agree! There are times when ideals become belief systems, then belief systems become religions. At that point the original ideals become lost to the dogmas they create. It doesn't make any sense NOT to reuse something that would otherwise be considered waste.

Kada Ga wrote:


The roofing material, is it safe?  Is there anything in there that is leaching?

If there is, I haven't seen any effects at all after using it for years.  My plants and trees all seem to be doing great, and this is material that is now being used for something great instead of sitting in a landfill somewhere for the next 100 years.  

For roofing rubber material it would take around 60 years of direct sun exposure to initiate the breakdown of the material. Most of this stuff is vulcanized without any Carbon black or other additives except what they use for a UV filter.

Permaculture is a contraction of the terms Permanent and Agriculture so it is designed to produce food, fiber and fuel that is for sale to others.  

I don't think people interested in bringing health back to the earth mother should get into quibbling about methods that work and are not contributing to the destruction or adding more CO2 to the atmosphere.
I do think people should be looking for, and using the most sustainable methods, that meet the above two criteria then they can add in carbon sequestering that will help reduce the amount of CO2 in the atmosphere. (which has increased by 50,000 percent (or more) since the beginning of the industrial revolution.

I'm with Redhawk, Todd, and Mike on this one. Don't let the perfect be the enemy of the good.

I think it's important to remember that, of the three R's, recycle comes last. The only part of reduction that we can reasonably engage in is as an active consumer, choosing to reduce the packaging that comes with our goods, by buying in bulk, for instance, or by reducing our overall consumption of goods. That leaves reuse.

There are so very many posts on this site about reuse. I would venture to say that reuse IS doing better. The materials being discussed, at least the rubber roofing material, as mentioned, is reclaimed from the waste stream, and has spent it's useful life out in the elements already. I would expect the amount of offgassing to have dropped off already, and if it is removed from the garden area and disposed of before the UV damage causes bits to flake off, the likelihood of there being anything nasty left in the soil is negligible. And on the off chance that anything unintended remains, that's what fungi are for.

For me, Jim, permaculture is a term that was coined by Bill Mollison. He coined it, so he got to define it. It is a design philosophy that includes your narrowed definition, but far exceeds it in scope. Bill unfortunately can't clarify for us any longer, but he left us his book, and Geoff Lawton, and a whole lot of people doing work in and thinking about this design philosophy. I think their collective permacultural cred far outweighs mine.

I think it's easy to be dogmatic and judgemental, and takes far more effort to look at specific circumstances and details and assess real-world risk and consequences.

From a practical standpoint, it is accepted practice that to get some systems up and running in some circumstances, less-than ideal measures, like earth moving with large equipment, for instance, or other large-scale measures to alter hydrology, are necessary, and that their long-term benefits far, far outweigh the slight, short-term, localised, and likely imagined, negative impact.

-CK

Hello everyone. Please indulge the “new guy”.

I would like to set aside the merits of using temporarily re-purposed items intended for the landfill. I think it is only a subset of a larger gardening issue that needs to be discussed. In this case, I would suggest there are 2 goals that need to be considered and prioritized as part of this discussion.

#1 “I want to have a weed free garden.”

#2 “I want to optimize my garden soil’s health.”

Prioritizing these goals would need to include short term and long term objectives. Consideration should also be given to how decisions concerning one goal will impact the other. Other considerations: expense, time, labor, and the return on the effort invested (quality and quantity). The gardener needs to determine - from themselves - which goal is more important?

I think Jim has offered a sufficient definition of permaculture for this discussion. Truth is, I think that a waterproof ground cover could easily be included as part of someone’s “permanent long term agriculture”.

It has been proven, waterproof ground cover will help eliminate weeds. But I would invite the gardener to explain how it “works in cooperation with nature and earth”. How is it used to optimize soil health?  Is that more important than eliminating weeds?  Are there better choices available that would satisfy both goals?

Or - perhaps the idea is (as I think Chris suggested), one will be used to meet a short term goal with a long term goal in mind (which would include a transition).

edit to add ****

In realilty - none of this answers the questions in the OP.    ;-)

At my place, this year's weeds are next year's soil fertility.

I prefer tarps.
I think it gets high enough to kill alot of soil life, so will probably have to re-inoculate with some worm tea.

The only reason to use any sort of "barrier/light block" is for the commercial growing of crop plants. Where you need to keep competition to a minimum and the use of these also reduces the use of chemicals that poison the land.
Use of any light barrier will stop plants from growing. If heat gathers under the barrier, the microbiome which is necessary for soil to be soil will die just like the plants you didn't want growing there.
Just because something works does not mean it is a good idea to use it, all the "Cides" work, they also have terrible side effects.
If you really have to have dirt instead of soil, it is easy to create, just lay black tarps or plastic on the soil and let it sit there for a few months of sunshine, you will create dirt from your soil. Then you can add some sort of fertilizer, I don't see this as productive.

90% of the people I meet that say they are "into permaculture" are gardeners not farmers growing items for sale on a large scale, there are only about 8% of those(farmers) in the global scene of earth mother restoration.
While it is great to want to grow your own food, that is tip of what permaculture is all about, it is really aimed at both the hobby grower and the commercial grower, the emphasis of Mollison is to get commercial farms using the methods, that is agriculture.
I meet far to many people who do far too much quoting of Bill's book and far to little actual implementation of the ideas he put into his book. He wrote it so it would be used in its entirety not this bit or that bit of the book.

I've been at this myself since the mid 1960's and all the farms I've set up are still going strong or they have succumbed to greed and become housing developments, taking that land out of production.
It is a struggle to get people to lay aside what they have known to work all their lives. Once you get them to try the "new" ideas and they get better results, that still doesn't mean they are going to jump in with both feet, they tend to move slowly into the new.
That is what I dealt with for 16 years and still deal with on a regular basis. Once the farmer sees his bottom line is better, the receptiveness of change makes sense and they move forward into restorative farming practices.

There isn't a real need to "get rid of the weeds", if you are building your soil to allow maximum production of any plantings the weeds will end up gone mostly because you made your soil better and thus inhabitable by the "weeds".
What most people call weeds are usually indicator plants that are telling you the current condition of your soil and that tells you what your soil needs, as you approach the improvement of your soil, you change the conditions and the "weeds" die or at the least change species.

Since the first rule of permaculture is OBSERVE, it seems to me that not enough understanding of what that word actually entails is present in most peoples vocabulary/dictionary knowledge.
If you actually observe, you will see all interactions at the time of observance and that means you will know what reacts to what and how it reacts and what that next step forward might be.

The true Mollison follower will not only know the principles, they will know how to utilize them in the best ways for their plot of land, which might have several different sets of circumstances within that plot of land that need different approaches for best results.

My farm is not yet a commercial operation, and now with the health problems it may never become what I originally intended.
As it will for most people, situations come up that make you have to adjust or simply totally change your initial plan. In my case it has already gone through 4 series of changes but these are just hiccups or perhaps Wakantanka is guiding me towards a goal.

Keep an open mind, learn all you possibly can and apply what you learn then learn from that. Everything moves in circles, just as everything is connected, so too are we connected to our earth mother and even the universe.

Redhawk

I am now thinking I may turn it into a learning center for permaculture, where people can come and do some of the work of permaculture and learn by doing.

Leave it to Redhawk to lend some perspective to a topic.

So what are we killing? Probably pioneer species and indicator species, along with anything else nature is trying to bring in to remedy a situation we are probably only a little aware of, along with all the soil life that does all the real work in the garden.

And while, sure, the organic matter will still be present, and sure, the soil life in the surrounding area should quickly return to the dead zone encouraged by the light blocking layer, and sure, when they don't hop to it as we demand, we can culture them in compost extracts and import them to the dead zone to decompose the organic matter and feed the worms, what we have done, in effect, is resort to the nuclear option.

So my questions in response would be, why don't we want these plants that some call weeds growing there? If they do, in fact, need to not be there for your system to work, is there a less-destructive method to move or otherwise get rid of them? Could they, in fact, be chopped and dropped?

In the event that the weed pressure is so high that you need that light barrier layer, is there another option for a light barrier layer that doesn't nuke the soil life? Maybe like a six inch layer of woodchips? I am not a personal fan of newspaper and cardboard, but those, at least, won't nuke the soil life, and they are viable, water and oxygen-permeable biodegradable options, and if you go with any amount of wood chips, having the fungal life in the soil to sequester heavy metals and toxic gick from the inks and adhesives will address problems from that direction.

Personally, I liked what happened in my hugelbeet when I dropped a three inch layer of woodchips on top of the soil, and then the butternut squash took off. I couldn't really see the wood chips for the squash leaves, and the fruit themselves had lots of airflow, sitting on top of them.

Upon reflection, I know what sort of choice I would make.

-CK

In my case, if I didn't use roofing material to kill the existing quack grass, I would have to till, and the quack comes back 1000 times worse when you chop the roots up.  Improving the soil alone doesn't make quack grass leave.  It makes it happy.  The best soil I have is quickly overrun by quack if I leave it alone.  The crop that is planted in the area doesn't seem to matter.  The only way I can establish perennials is to put down the roofing material, wait for months for the quack to die, and then plant it immediately upon moving the roofing, or by covering the now-bare soil with a heavy layer of wood chips and planting in "holes" I make in the chips.  The soil life appears to bounce back much more quickly than the quack grass does.  The quack still comes in from the sides if I don't leave a barrier of roofing or comfrey around any area cleared.  Quack that does invade again is pulled easily from areas that have been wood chipped heavily for a couple years, so unless I neglect an area totally, the roofing material only treatment only needs to be done once.  Also, I don't care about a weed-free garden.  I care about an area I can plant in that isn't overrun with quack to the point nothing else has a chance.  The compost, wood chips, biochar, and other organic material I pile on every year is working to optimize my soil.  I am working to be able to grow something other than quack grass in that soil.

hau Kola Todd, I agree that in your case eradication needs to come first and that is best done with your methods, I believe we have talked about that.

I'm working long distance with a friend that has the same problem and what he is doing is what I term Thermo Nuclear War Fare. We are laying out his growing spaces and triple tarping them for a full year, thus we are making dirt out of soil but this is rather necessary since he had already tried everything short of poisons.
Once we have dirt down to about 12 inches, we should be able to raise lazarus from this dead state with two applications of compost (rotted manured straw) and two applications of compost extract. Then he will plant a Lucerne, yellow clover, daikon, turnip, buckwheat mix for his first chop crop.
Then he wants to add a second round of compost extract. I already know he has a good microscope so I suggested he do an assay of the organisms before he adds that second round of extract so he can determine just which organisms he needs to make additions to.

This will work for anyone fighting quack (Bermuda) grass rhizome infestation.

Redhawk

Thank you for posting that Redhawk.  I think I will follow that exact plan on a large new area I am starting this spring.

Hey Todd,

Sounds like yours calls for the nuclear option. I have had to deal with that stuff. I liked it even less than Japanese knotweed.

Mine was easier, though, I guess. I needed access to my new hugelbeet, and more soil volume, so I dug a path two feet deep around it and filled the depression with wood chips.

The grass I pulled, incidentally, got tossed into a black contractor grade garbage bag to cook in the sun with the aforementioned knotweed. By the time I looked at the bag again, it had largely liquefied.

And while my weed DMZ was a little more work, I got a soil life bioreactor out of the deal, too.

But I guess some stuff needs eradication so it doesn't overtake everything. I suppose that's why we have light barrier techniques in the permaculture tool shed.

-CK

My bindweed is rather like quack grass, only more so, since it climbs the plants and mowing won't stop seed set. (I have quack grass too, and Canada Thistle to boot!)

And yes, I haven't found that soil improvement really helps much. It does make the soil softer so that they are easier to pull, but the root systems are just too established.

I have a large area covered with black plastic at the moment, 20m by 20m worth, In the spring that will come off and it will get moved down to the next patch that needs clearing.  I have not found it does anything bad to the soil, the voles and worms love it under there, due to the nature of my field even being covered in that large an area of waterproof cover it doesn't dry out, on the scale I need to clear mulch is a no go, the shear amount would be horrifically expensive. there's no large  quantities of free stuff here, it all goes to power production.  I want some wood-chips for around my rhubarb and paths.. but at $30 per m2 plus delivery, I may have to give that a miss.

I also do not want to have large quantities of mulch lying around as it retains water, cools the soil and encourages slugs and snails! (yes yes I know the first two are normally considered a good thing, not by me)

What I'm doing for my no-till plantings is this: Early in spring (first part of Sept if I'm on the ball) I put down weedmat directly over the section of pasture that I'm going to plant. The material I'm using is woven polyethylene, which is permeable to water and air but blocks sunlight. When I pull it up, normally 6-7 weeks later, all the pasture biomass above the surface is gone and in its place is a complete coverage of worm castings. By this sign I'm assured that the soil life isn't taking too much of a beating. I then harrow ever so lightly with a rake and plant directly with corn, beans, pumpkin, sunflower and other grains or cover crops as time or space allows (buckwheat went into one patch this year). I then scythe some part of the paddock that is long and rank (like around an alpaca dung spot) and broadcast that over the entire plot. The seedlings come up through the mulch and if they're not too badly browsed by birds and bunnies they quickly overtop whatever germinated at the same time from the seed bank already in the soil and wasn't deterred by the mulch layer. Oh, and the dandelion and dock just laugh and resprout from their taproots. That's fine, since they're welcome in my pasture (although I pull a lot of the dock before I cut my hay because the dry tops play hell with turning and baling and no one wants to eat them).

This system is working pretty well for me. I used to use old carpeting, but the work and vehicle travel involved in procuring the stuff, plus the fact that I only got one or two seasons out of it at best, made the decision to switch to plastic a lot easier. I'm continually using different sections of the paddocks for cropping and planting directly into grass-dominated pasture gets nowhere, so some means of suppression is required. Someday I'd like to try undersowing a cover crop that could actually outcompete the pasture over winter and then be undersown, chopped and dropped without the need for weedmat. So far I haven't found the grail. Meanwhile, I try to take care of the plastic sheets and hope to get at least a decade out of them (on year three now and looking good).

This topic would be better discussed in the cider press. Locking this thread to further discussion. Those of you that have sufficient apples, feel free to continue this conversation in Toxic Gick.