Weed Barrier Under Artificial Turf, Do You Need It and Where Does It Go?

This page is for homeowners and DIYers deciding whether to buy weed barrier fabric for a turf install, and if so, which kind and where it goes. You will be able to make the call for your soil and weed pressure, and avoid the drainage problems that a poorly placed fabric can cause. It fits into step 9 of our full installation guide.

Do you need a weed barrier under artificial turf?

Weeds reach turf two ways: from below (perennial roots and rhizomes left in the soil) and from above (airborne seeds that land in the infill and sprout). A barrier only helps with the first. Seeds that land on top are a maintenance issue covered in weeds through turf.

A well compacted 3 to 4 inch crushed base is itself a strong barrier. Most annual weeds cannot push through it, and turf backing blocks light. That is why many professional installers skip fabric on ordinary sites. The cases where fabric earns its cost are specific.

Should weed barrier go above or below the base?

Below the base is the stronger position in most installs. Laid directly on the compacted sub-grade, geotextile performs two jobs at once: it blocks rhizomes from below, and it separates the soil from the base rock. That separation matters. Without it, on soft clay, rock gradually presses into the soil and fines pump up into the rock, so the base loses thickness and drainage capacity over a few years.

Above the base (directly under the turf) is common in some regions and in big-box DIY instructions. It catches the occasional weed that germinates in the base itself, and gives a clean surface to lay on. But it has real downsides:

• Drainage: a fabric with a low flow rate becomes a second layer water must pass through, and fine silt from infill can clog it over time.
• Odor: in pet areas, urine can sit on the fabric surface rather than flushing into the base, a known cause of turf smells.
• Movement: turf nailed through fabric can shift slightly on the smooth layer, and the fabric can wrinkle under the backing, showing as ridges.
• Little added benefit: turf backing already blocks light, so seeds in the base rarely survive.

Our rule: if you only put fabric in one place, put it under the base. Use fabric on top only when there is a specific reason, such as a very thin base over weedy soil, and choose a high-flow non-woven product.

Woven vs non-woven: which fabric should you use?

Geotextiles come in two main types, and the difference matters for drainage.

Non-woven fabric is usually the better choice under turf because it lets water pass through freely while still keeping soil out of the base. Woven fabric is stronger and useful where soft ground needs reinforcement, but its tighter structure passes water more slowly.

Avoid thin "landscape fabric" sold for flower beds, plastic sheeting, or anything perforated with small holes only. Plastic sheeting is impermeable and will turn your turf into a shallow pond. Spun-bonded bed fabrics are often too light to survive compaction without tearing.

How to install weed barrier below the base

1. Excavate and compact the sub-grade, shaping the drainage slope into the soil. See base preparation for compaction targets, and the base material calculator for the rock that goes on top.
2. Treat or remove aggressive weeds (see the herbicide section below).
3. Roll out the fabric across the slope direction, overlapping adjacent sheets by 12 inches. On slopes, lap the uphill sheet over the downhill sheet.
4. Pin it with landscape staples every 3 to 5 ft and at all overlaps.
5. Run it up the edges a few inches against bender board or curbs so no gap is left at the perimeter.
6. Dump base onto the fabric from the edge and spread forward, rather than driving wheelbarrows directly on bare fabric, which can tear or bunch it.

When does weed barrier hurt drainage?

Fabric hurts drainage when it is the wrong type, in the wrong place, or clogged.

• Wrong type: woven or very dense fabric directly under turf on a flat site.
• Wrong place: fabric on top of a base made of dense road base, creating two slow layers.
• Clogged: fine dust from DG, rock dust or infill gradually seals the fabric surface. This is more likely with fabric on top of the base.
• Wrinkled: folds in fabric under turf create small dams and ridges.

Diagnostic: if you have puddling on turf that was installed over fabric, pull back a corner after rain. Water sitting on top of the fabric, with drier base beneath, points to the fabric. Our standing water page has the full diagnosis, and testing drainage explains how to measure flow.

Should you use herbicide before installing turf?

Herbicide pre-treatment makes the most sense where perennial grasses or sedges are established. Bermuda grass and nutsedge regrow from underground parts that survive excavation, and turf installed over them can see shoots appear at seams and edges within one season.

• Timing: apply a systemic, non-selective herbicide to actively growing weeds 1 to 2 weeks before excavation, so it moves down into roots before you dig. Follow the label for re-entry and wait times.
• Repeat if needed: for heavy Bermuda, a second application after regrowth gives better control.
• Pre-emergent: some installers apply a granular pre-emergent on the sub-grade. It reduces seed germination but does nothing for established rhizomes.
• Non-chemical options: solarizing under clear plastic for 4 to 6 weeks in hot summer weather, or thorough mechanical removal of runners.

Always follow product labels, keep products away from water features and drainage paths, and consider pets and children. If you want to avoid chemicals, a below-base non-woven fabric plus careful runner removal is the main alternative. Environmental tradeoffs of turf more broadly are discussed in environmental impact.

Frequently asked questions

Can weeds grow through artificial turf?

Weeds rarely grow up through the backing itself. They usually emerge at drainage holes, seams and edges, or sprout from seeds that blow into the infill. Most are shallow-rooted and pull out easily. Persistent shoots from below usually mean rhizomes were left in the soil and the base or barrier is thin at that spot.

Does weed barrier stop turf from smelling?

No, and placed on top of the base it can make odor worse in pet areas by holding urine at the surface. Odor control depends on drainage through the base, regular rinsing and enzyme cleaning, and infill choice. For dog areas, keep fabric below the base or omit it, and see pet odor prevention.

How long does geotextile last under turf?

Buried under base and turf, a quality polypropylene or polyester geotextile is shielded from sunlight and typically outlasts the turf, often for decades. Degradation comes mainly from UV exposure during installation, so cover it with base promptly and do not leave it in the sun for weeks.

Can I reuse old landscape fabric under new turf?

Usually not. Old fabric is often torn, clogged with fines and wrinkled, and much of it is light bed fabric rather than a proper geotextile. Remove it during excavation. If it is a heavy geotextile in good condition below an existing base you are keeping, it can stay in place.