I have encountered a curious situation I'm hoping someone can solve.

When I started digging a hole to plant a young bush in my front yard, I saw 1-2 inches of wood chip mulch, then a black landscaping fabric, then soil, then TWO MORE layers of landscaping fabric, then finally a blue tarp that looks thick and possibility slightly water proof.

My question: What is the function of this tarp?

There are trees and other bushes just a few feat from where I dug. I can't imagine these plants rest above the blue tarp. So the tarp can't be sealing off that whole area. But could it be there to control/guide the surface water?

We are in upstate New York, in a forested area on the slop of a rocky hill. The landscaped yard is higher on the slope than the house. There's a french drain right below the area, before the house. Here are pictures:

the big view of the area:

Closeups of the hole and the tarp: closeups

In case it helps, something similar was asked here before and everyone said remove the tarp but someone suggested it may have been put there to control the surface ground water. Here is the conversation: What's the function/purpose of the waterproof tarp a few inches beneath the ground in my yard?

I appreciate all help and clues! We moved here recently and I can't find out who did the landscaping. It's possible that it all was done many years ago.

  • The tarp will inhibit gas transfer and various other good things within the soil. It's not a good thing to have. Likely it was installed as a cheap landscape cloth (which has its own problems).
    – Reid
    Apr 25, 2021 at 3:42

1 Answer 1


My neighbour does this and it works as a weed suppressor for a while. Tarp is not very porous to water to it keeps the mulch or soil on top moister than usual which encourages weed growth. The edges tend to stick up and get caught if you use a weed whacker.

For your situation the least work is just to cut the tarp out with an area for the bush and plant away.

A more thorough investigation is to do some sample digging and figure out how large the area the tarp covers.

As far as water control if you mulch and have shrubs they will soak up water. I don't see a significant slope in the photos which would be needed to send the water to the french drain. The tarp actually prevents water from soaking in. Unless there is a source of a significant amount of water coming into the planting area the tarp is not doing much

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