Can weeds grow in artificial grass?

Most weeds start on top

The turf can’t grow weeds. What grows them is the layer that builds up in it.

Seeds arrive on the wind. The UK’s Sports and Play Construction Association, whose code of practice covers synthetic pitches, says weeds that turn up on the surface usually come from wind-blown seeds. They need something to root in, and a surface full of fibers collects it: dust, leaves, pine needles, tree flowers and grit.

That layer is the real problem. The Synthetic Turf Council says leaves and debris left on the surface work down into the system, where they slow drainage and compact the infill. It tells field managers to remove organic material promptly to hold back algae, weeds and moss. SAPCA describes leaves and needles rotting down into a skin that holds water. And the UC Master Gardeners put it plainly for home lawns: crabgrass and other weeds can grow in artificial turf, and leaves that aren’t cleared get ground in. UF/IFAS Extension says the same of fallen leaves: they still have to be removed from synthetic turf to prevent wear and tear.

So look where the debris gathers: under trees, along planting beds where soil and mulch spill over, and in corners where leaves pile up.

Some come up from below

Weeds from below are what a barrier is for. A fabric laid before the base goes in helps against them, but it has limits:

• Tough perennials get through. UC IPM notes that yellow nutsedge can grow through most landscape fabrics, with thicker fabrics holding it back better.
• Gaps let weeds in. UC IPM also warns that weeds grow through any gap in the fabric, so overlaps and edges matter.
• Anything on top feeds them. Washington State University’s extension horticulturist writes that soil or organic matter on top of a fabric speeds its colonization by weeds, and that weeds eventually grow on top of and through it.

That’s why clearing the ground matters more than the fabric. Existing weeds and their roots should come out before the base goes in. WSU’s own example is a bed where bindweed and horsetail roots had covered the fabric buried under the soil.

Keep the fabric covered, too. WSU notes that geotextiles can degrade in as little as a year when left in sunlight. And where wildfire is a risk, the IBHS Wildfire Prepared Home checklist lists exposed weed cloth among the combustible groundcovers to clear from the first 5 feet around a house. Fabric belongs under the base and tucked under the border, not showing at the edges.

What goes under turf where you live

• Colorado. On swelling clay, the Colorado Geological Survey discourages plastic sheeting because it traps moisture. Non-woven fabric, it says, controls weeds and slows infiltration but still lets moisture evaporate. If your base has a barrier under it, it should be non-woven fabric, not plastic.
• Florida. The state’s standard for single-family lots requires permeability through the turf, the backing and the subgrade under Rule 62-308.100. Whatever goes under the base has to let water through.
• Denver Water’s rebate. You may have read that Denver Water won’t fund weed barriers. That’s a condition of its HOA and commercial landscape program, which won’t pay for designs that include artificial turf, landscape fabrics or weed barriers. It isn’t a rule about turf. Our Colorado rebates guide covers which providers pay for what.

Getting rid of the weeds you find

• Pull them young. The Synthetic Turf Council says weeds come out easily by hand before an infestation takes hold.
• Get the whole root. SAPCA’s code stresses pulling out the full root rather than breaking it off, since some weeds come back stronger when they’re only cut at the surface.
• Deep-rooted weeds. SAPCA suggests an appropriate weed killer for those, and never an oil-based one. At home, choose a product your turf maker approves, and follow the label where kids and pets play.
• Brush out what’s left. A pulled weed leaves soil on the fibers. Brush it out and blow it off, so the next seed has nothing to root in.

Stop the seedbed forming

1. Clear debris regularly. A leaf blower on a low setting or a rake does it. Penn State’s sports surface researchers warn against blowing out the infill along with the leaves.
2. Brush. Brushing keeps the fibers upright and the infill loose, and the Synthetic Turf Council says it helps deter organic growth.
3. Hold the edges. A solid border of pavers, rock or concrete keeps bed soil and mulch off the turf.
4. Mind the trees. The Synthetic Turf Council advises against leafy trees right next to a field. At home, prune what hangs over the turf.
5. Pick up after pets. The Synthetic Turf Council says to remove organic material, animal waste included, as soon as possible to hold back weeds, algae and moss.

Moss and algae grow in the same debris, so the same routine handles them too: see moss and algae on artificial turf.

A weeds checklist

• Where are they? Record the patches and look for collected soil, leaves or seeds. Location is a clue to investigate, not proof of where the roots started.
• Pull them young, whole root and all.
• Clear leaves and debris weekly in leaf season.
• Brush as the product’s instructions and actual debris buildup require.
• Keep solid borders along planting beds, with any fabric tucked out of sight.
• Recurring or deep-rooted growth: have it assessed before lifting turf or changing the base. Ask which part of the installation needs attention and how that was established.

On the free visit we measure the space and check the ground, including what’s growing in it now, before anything is priced.