Question about weed killing plastic.


Garden Ornament
Dec 30, 2019
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I got a roll of heavy duty plastic to kill off the weeds in part of my garden. My question is, have you had better results with the ground wet or dry before putting it down?
Salt could do a job. Bring a solution of around 1 cup of salt to a boil in 2 cups of water. To kill them, pour directly on the weeds. Another equally successful way to destroy weeds is to apply salt directly to weeds or unwanted grass that comes up between patio bricks or blocks.


Garden Master
Sep 4, 2009
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East Central IL, Was Zone 6, Now...maybe Zone 5
No salt! Sorry @YourRabbitGirl . Salt is what the Romans did to destroy the agriculture in Carthage, or, at least subdue it.
Salty soil can grow many things but it will kill others and it will take a long time to leach Out of the soil where you apply it. There are other solutions that won't harm the soil, but may have some efficacy, more or less.
Boiling Water
Soapy water
Covering with a thick layer of compost works very well, although some established weeds can grow through it. You can take a paintbrush and brush the leaves of any plant that you do not want and it will soak the herbicide in and die without affecting surrounding plants.
You could try compost and cover That with plastic, too.


Garden Addicted
Oct 15, 2017
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mid-Michigan, USoA
plain cardboard and woodchip mulch on top works very well for smothering weeds in a garden bed - perennial gardens especially. if you use a few layers and overlap the seams of the cardboard you can usually get one to two years out of such a treatment. if it starts getting a lot of weeds coming through before it gets too bad scrape back the surface layer of wood chips and put down more cardboard and then put the woodchips back on the cardboard. this is often a much faster process than weeding a large area.

the bonus is what happens after some number of years. since you are not stirring the soil much you are not moving weed seeds around and causing more weeds to sprout. so you may get to the point where you have just layers of woodchips and the broken down humus from the woodchips, the cardboard will be eaten by worms and other detritovores. after 5 or more years you may have enough humus that you can harvest it and put some in the vegetable gardens (or what i do with it is use it partially in the worm buckets and eventually that goes out to the vegetable gardens as fertilizer). so you can maybe avoid having to put down new cardboard and just add more fresh wood chips on top as the rest of them get broken down.

a good sign that you have a lot of humus in your mulch is that the mulch will start sprouting more weeds (that have likely blown in on the wind). you can remove and replace the humus/partially/mostly decayed woodchips or top it off, but if there are a lot of weeds sprouting it is probably a good idea to plop some cardboard layers on top and start over again.

i wish i had time and a truck to go get some wood chips now as i'd like to smother some grass we've been mowing for a long time. it makes a mess out of every garden around it and has a huge amount of edge there which means a lot of gardens are affected by it spreading seeds and plants all the time. i have some nice large pieces of extra thick cardboard without any holes in them to use up... i'm going to have to hold it down with rocks. as it is getting too hot for heavy work i'm not enthused with the idea of doing this kind of thing right now anyways.

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