Artificial grass has become a top choice for homeowners and commercial property owners who want a clean, green, and low-maintenance outdoor space. But one question often comes up in landscaping & gardening with artificial turf: Does mold grow under artificial grass?
The short answer: Yes, it can—but only under certain conditions. Let’s dig into the reasons why mold may grow, how to prevent it, and what to do if you spot it.
What Causes Mold Under Artificial Grass?
Mold thrives in damp, dark, and poorly ventilated areas. While artificial turf is designed to be water-resistant and well-draining, it can still create an environment for mold if the installation or maintenance is not done correctly.
1. Poor Drainage
Artificial grass sits on a sub-base, typically made of crushed rock or gravel. If the sub-base doesn’t allow water to drain efficiently, moisture can collect beneath the turf. Over time, stagnant water becomes a breeding ground for mold.
2. Organic Debris
Leaves, soil, and other organic materials can fall onto the turf and break down, especially if left for too long. These materials feed mold and bacteria. Combine that with trapped moisture, and you’ve got the perfect mold habitat.
3. Shaded Areas
Mold prefers dark or shaded areas where sunlight can’t dry out excess moisture. Turf areas that don’t get enough sun, especially in corners or near walls, are more prone to mold growth.
How to Prevent Mold Growth Under Artificial Turf
Proper installation and regular maintenance are the two key defenses against mold.
✅ Use the Right Base Materials
Choose a high-quality sub-base like crushed granite or decomposed granite. Avoid compacted soil as a base—it holds water and encourages mold. A professional turf installer will make sure the sub-base is compacted correctly and graded to allow runoff.
✅ Install a Weed Barrier
A weed barrier layer beneath the turf helps block organic materials and minimize the chance of mold. Bonus: it also keeps weeds from sneaking through.
✅ Ensure Proper Drainage
Modern artificial turf often includes perforations or drainage holes that allow water to flow through. Make sure your turf has proper drainage built in and that the base material promotes quick water dispersion.
✅ Clean the Surface Regularly
Use a leaf blower, stiff brush, or hose to clean off organic debris like leaves, twigs, and pet hair. The longer debris stays on the turf, the higher the risk of mold growth.
✅ Use Antimicrobial Infill
Silica sand or rubber infill can trap moisture, but antimicrobial infills help prevent mold and bacteria buildup. Choose infill options designed to resist microbial growth for added protection.
Signs of Mold Under Artificial Grass
You likely won’t see mold directly unless you pull back the turf, but there are telltale signs:
- Unpleasant Odors: A musty or sour smell may indicate mold or mildew below the surface.
- Discoloration: Dark patches or black spots on the turf can be signs of mold trying to break through.
- Soggy Spots: If parts of your lawn stay wet long after it rains, the drainage could be blocked, leading to mold issues below.
How to Treat Mold Under Artificial Turf
If mold has already started to form, quick action is crucial.
1. Surface Cleaning
Start by cleaning the turf surface with a hose and stiff brush. Use a mild detergent or a turf-safe mold cleaner. Avoid harsh chemicals like bleach unless the turf manufacturer explicitly approves it.
2. Disinfect
Mix a solution of equal parts white vinegar and water. Spray it on the affected areas and let it sit for 30–60 minutes before rinsing thoroughly. Vinegar is a natural mold killer that’s safe for most synthetic grass products.
3. Lift and Air Out
In serious cases, you may need to lift a section of the turf to allow the area underneath to dry. If necessary, consult your installer or a turf professional for proper reinstallation.
Proactive Tips for Mold-Free Turf
- Rinse pet areas frequently to avoid ammonia buildup.
- Trim overhanging trees to let more sunlight in.
- Avoid placing heavy outdoor furniture in one place for too long—it can trap moisture beneath.
- Schedule a seasonal deep cleaning to keep your artificial lawn in top shape.
Mold under artificial turf is not a common issue—but it can happen if the grass is poorly installed or neglected. Landscaping & gardening with artificial turf comes with many benefits, including lower maintenance and water usage, but it still needs attention.
By ensuring proper drainage, cleaning regularly, and using quality materials, you can enjoy a lush, green, mold-free lawn all year round.
Need help with your turf installation or maintenance in California?
At Cal Pro Artificial Turf, we specialize in premium turf solutions that look natural, last longer, and drain effectively. Contact us for a free estimate today.