What's the function/purpose of the waterproof tarp a few inches beneath the ground in my yard?

Question

When I tried to plant some plants and dug up a hole in my front yard, it appeared that there is a waterproof, at least it appeared to me so, tarp under the soil and mulch mixture, and it extends to a very large area, probably as large as most of my yard. The material of the tarp looks similar to this.

Source

What is it called? What is its function/purpose? When planting perennial plants, should I dig through this tarp or not? If not, the depth of the soil/mulch does not seem deep enough for the plants to develop a large root system.

This yard is located in Pacific Northwest which alternates between a rainy fall-winter season and a dry summer season.

Answer 1

That is most likely landscaping fabric designed to block or inhibit weed growth.

If the soil layer is too thin where you intend to plant perennials, feel free to cut out a circle of the fabric and plant appropriately.

Answer 2

Get rid of it! Talk about destroying even a tiny bit of a natural soil system...landscape fabric was made only to put below gravel on top of soil so that the large rocks don't sink and the soil come up causing your rock/gravel to disappear. It is not meant for weed control. Pull it up.

In no way does this fabric provide any benefits whatsoever. In fact it causes many problems...and I could go on. Don't run out and plant in that few inches of soil that is cut off from the entire body of your garden soil and ecosystem.

Answer 3

Apparently this may be a strategy to control local ground surface water. Are there water control or drainage issues on this property? In the PNW I can image either or both. Is there a french drain at the lowest point of the property?

Removing it without knowing more about the purpose and reasons may have unintended and possibly undesirable consequences. That doesn't look like landscape/weed control fabric to me.