We’ve used landscaping fabric with varying degrees of success in our yard over the last ten years, so is it fully porous or not?

Landscape fabric is designed to let water through and stop it from evaporating out of the ground. It comes with a non-porous coating to help roll it out more easily, but after 24-48 hours this degrades and the fabric becomes fully porous. Heavy rain on landscape fabric seeps through in under a minute.

Let’s dig down (pun intended) into the topic of landscape fabric in more detail, and discover its waterproof properties and usage in many different areas of the yard…

How Fast Does Water Go Through Landscape Fabric?

We’ve used landscape fabric in our garden for years and once tested it with a bucket of water when laying it down. Water hardly pools on it at all.

In under a minute, all the water had seeped through. That’s because most landscape fabrics have lots of holes. Thousands of holes. 

Does Water & Rain Flow Through Landscape Fabric?

Yes, landscape fabric is designed to allow water to seep through it, so any plant roots growing under it will still get water. Billions of holes, right? 

The problem is, years down the road, those billions of holes can get clogged up. In spots where the holes get clogged up, water will start to pool. 

Here’s a good resource with pros and cons of landscape fabric.

Should I Use Landscape Fabric in My Flower Bed? (Before Planting)

Most experts say you should avoid using landscape fabric in flower beds. Why? Because while landscape fabric may hold weeds at bay for a while, landscaping fabric also acts as a barrier to all those soil-dwelling critters that keep your garden beds healthy.

Landscaping fabric is marketed as a weed barrier. The problem is, landscaping fabric doesn’t guarantee that you won’t have weeds. Weeds can grow on top of the fabric and their roots can push through it. 

Flower beds and vegetable beds need the best soil possible. Landscaping fabric is a barrier for oxygen and all those critters that we want burrowing in the soil.

And, if you rely on perennials to reseed your flower beds, landscape fabric isn’t for you. Although seeds may start above the fabric, they won’t be happy growing there for long.

Do You Put Soil on Top of Landscape Fabric?

Not usually. Weeds need some dirt to grow in, so if you are trying to avoid weeds, you won’t want to put soil on top of your fabric. Most experts recommend laying down mulch on top, not soil.

Layering some nice shredded bark or gravel mulch on top of landscape fabric will look beautiful. After a season or so, though, your beautiful bark mulch will begin to break down. 

After a season, your old bark mulch won’t be looking so bueno, thanks to blown-in sand, weeds, sticks and leaves. You’ll dump more mulch on top of the old to freshen it up and all those things you’ve buried will start decomposing.

After several seasons, you will have successfully made a lovely rich soil layer on top of the landscape fabric. Your weeds will love you for it.

Can I Use Landscape Fabric for a French Drain?

While a landscape fabric can help weed control, it is not suitable for engineering application or using it for a drainage application. A permeable geotextile would be more suited as a pours material to stop substances from going into the drainage system.

Then, check with your HOA or area planning permission. The drained water will have to go somewhere else – make sure it doesn’t flood your neighbors flower beds.

Then, dig the drain trench. Make sure to create enough slope, so that gravity will help you drain the water away from your wetlands. 

Line the trench with permeable geotextile. Using a permeable geotextile in the French drain trench will help separate the soil from the drain rocks. Experts say to choose a heavy (4 to 6 ounce) non-woven landscape fabric. 

This fabric is like a heavy felt. Make sure to cut the fabric so that it can completely wrap around the drain rocks and the pipe, like an enchilada.

Add the drain rocks. Experts say to use natural, round rocks. Then, set your drain pipe in the trench, making sure the drain holes are facing down. Cover the drain pipe with more drain rock. Then, wrap the excess fabric to cover the pipe. Finally, cover with the soil or a drainage grate.

Here’s WikiHow on planning and building a French drain.

Should I Put Landscape Fabric Under Rocks?

The majority of landscapers say that this is the landscape fabric application they like best. 

Let’s say you are xeriscaping a large area and plan on having a “riverbed” of cobble-sized rocks winding through it. To prevent the cobbles from sinking into the soil after a few rains, you can first put down landscape fabric in the riverbed, then cover it with the cobbles.

Should Landscape Fabric Go Under Gravel?

Putting fabric under gravel is a way to stabilize the gravel, so it doesn’t sink into obscurity. Experts recommend burying the fabric no deeper than three inches.

Experts say that another useful way to use landscape fabric is for something they call gravel regret – yup, that’s a thing. On your gravel pathway, simply move a line of gravel to the side and cut the fabric. You’ll want to cut a wide strip. 

Then, pull up the edges of the fabric so you can grab a handful of fabric. Carefully drag the fabric with the gravel on top to its new home.

Can I Put Landscape Fabric Over Weeds?

Yup. You can put landscape fabric over weeds and even grass. Landscape fabric blocks sunshine, so anything with leaves will die.

Is It Better to Use Landscape Fabric or Plastic?

If you are trying to kill, or smother, everything in an area, then plastic will work. Plastic will block sunshine and water.

If you are trying to stabilize soil under a layer of heavy rocks, then use landscape fabric. Landscape fabric will allow some water to drain through.

Can I Use Two Layers of Landscape Fabric?

Experts say not to use two layers of landscape fabric. 

One layer of landscape fabric should allow water to drain through. Two probably won’t. Even one layer of landscape fabric can inhibit oxygen transfer to the soil. Two definitely will.

Why Shouldn’t I Use Landscape Fabric?

Big box stores sell it and many landscapers use it. It’s billed as a weed barrier. But the truth is, it’s not good for your plants and it’s really not good for the soil – which, in turn, isn’t good for your plants. And, while it may block weeds at first, eventually the weeds will grow on top of it and through it.

It’s not good for the soil. Let’s face it, soil is the single most important thing in a garden. If you have sick soil, you will have sick plants.

Healthy soil should have an amazing mix of life: organic matter, fungi, bacteria, protozoa, mites, and nematodes. It is literally crawling with worms, ground beetles, ants, millipedes, centipedes and spiders.

All the creepy crawlies in your soil produce nutrients that your plants need. Weed fabric inhibits the creepy crawlies you need to keep your soil healthy.

Conclusion: What Can I Use Instead of Landscape Fabric?

Instead of using a landscape barrier to prevent weeds, try using a biodegradable one. Or try to outsmart weeds with some stiff competition.

Instead of landscape fabric or plastic, try a layer of cardboard or newspapers instead. They will also suppress weeds for a while and both biodegrade. When they biodegrade, they will actually help the soil. We’ve experimented with all these methods in our garden and they all work pretty well.

Plants don’t like competition. They need their fair share of sunshine, water and nutrients. So, if you want to discourage weeds from growing in your gardens, crowd them out. Give them some competition. Plant ground covers.

This video on landscape fabric pros, cons and alternatives is definitely worth your time.