Plastic Sheeting For Weeds: How To Prevent Garden Weeds With Plastic

Rows Of Vegetalbes In The Garden Covered With Plastic Sheeting
(Image credit: poteco)

So you want to start a new garden space but it is so covered in weeds you don’t know where to begin. If you want to be a good steward of the earth chemicals aren’t an option, so what can you do? You’ve heard of using plastic sheeting for weeds, but can you kill weeds with plastic? It makes sense that you could prevent garden weeds with plastic, but can you kill existing weeds with a plastic tarp? Keep reading as we investigate how to kill weeds with plastic sheeting. 

Can you Kill Weeds with Plastic? 

You may have heard of or even have in your landscape, plastic sheeting laid under bark mulch or gravel; one way to prevent garden weeds with plastic, but can you kill existing weeds with plastic sheeting? 

Yes, you can kill weeds with plastic. The technique is called sheet mulching or soil solarization and is a terrific organic (yes, the plastic is environmentally unfriendly but it can be saved for reuse over and over) and no fuss way to rid a potential garden space of weeds. 

How does Plastic Sheeting for Weeds Work? 

The plastic is laid down during the hottest months and left for 6-8 weeks. During this time the plastic heats the soil to such an extent that it kills any plants beneath it. At the same time the intense heat also kills some pathogens and pests while inducing the soil to release any stored nutrients as organic matter breaks down. 

Solarization can also occur in the winter, but will take longer. 

As to whether you should clear or black plastic sheeting for weeds, the jury is somewhat out. Generally black plastic is recommended but there is some research that says that clear plastic works well too. 

How to Kill Weeds with Plastic Sheeting

All you have to do to kill weeds with plastic sheeting is to cover the area with the sheeting; black polythene plastic sheeting or the like, flat on the ground. Weight or stake the plastic down. 

That’s it. If you like you can poke some small holes in the plastic to allow air and moisture to escape but it isn’t necessary. Allow the sheeting to stay in place for 6 weeks to up to 3 months. 

Once you remove the plastic sheeting, grass and weeds will have been killed off and all you need to do is add some organic compost into the soil and plant!

Amy Grant

Amy Grant has been gardening for 30 years and writing for 15. A professional chef and caterer, Amy's area of expertise is culinary gardening.