Keeping a lawn lush and vibrant requires more than regular mowing and watering. Fungus often strikes even the most well-groomed lawns. At Lawn Doctor, we’re experts in treating fungal infections and protecting your lawn from further damage. Knowing how often and when to apply fungicide on lawns makes all the difference. Whether you want to prevent lawn disease or address a specific issue, we’re here to help you navigate the process.

What Causes Lawn Disease?

High humidity, damp soil, and warm temperatures create the perfect breeding ground for fungi, which can lead to lawn disease. Even common lawn care practices, such as overwatering or cutting grass too short, weaken grass blades and make them more vulnerable to infection.

Other factors, including heavy foot traffic and dense thatch buildup, prevent water and nutrients from reaching the roots, which stresses the grass and increases the risk of fungal growth.

Different fungi attack grass in specific ways and under particular conditions. For example:

• High temperatures and humidity spikes
• Low levels of nitrogen in your lawn
• Limited airflow and shady areas

When you know the cause, you can create a proactive plan that reduces the need for reactive fungicide treatments.

What Does Fungicide Do?

Fungicides attack the fungal cells that cause disease. They either inhibit spore growth, block infection pathways, or disrupt the fungi’s cell structures. Applying fungicide to a lawn forms a protective layer over your lawn or penetrates deep into the grass, eradicating fungi at the source.

Fungicide treatments come in liquid or granular forms, each with its own application techniques. Liquid fungicides offer quick absorption and treat severe fungal issues right away. Granular fungicides release active ingredients slowly, providing long-term protection.

By stopping the disease cycle, fungicides prevent further damage and allow grass to recover and fill in bare patches. However, applying them properly is essential to avoid overuse, which can damage healthy grass and soil microbes.

Is Fungicide the Right Treatment for Your Lawn?

Not all lawn issues require fungicide. If your lawn has patches of discoloration, thinning grass, or visible mold-like growths, a fungus may exist. For mild cases, adjusting basic lawn care practices may resolve the problem without fungicide.

More severe cases often require fungicide treatment. These include:

• Large, irregular patches, sometimes with rings of dead grass
• Discolored blades, often showing streaks, spots, or powdery coatings
• A musty or rotting smell
• Slimy or moldy coatings
• Wilting despite watering
• Fungal threads (mycelium) visible when dew is present

Our team at Lawn Doctor can evaluate your lawn’s condition and recommend whether fungicide is the right course of action and when to apply fungus control for lawns.

Types of Fungicide

There are two main categories: contact and systemic fungicides.

Contact Fungicides

These fungicides remain on the surface of the grass and act as a protective shield. They may need reapplication after rain or heavy watering, as they don’t penetrate the grass tissue. Contact fungicides work well for proactive lawn care, especially when fungi are most active.

Systemic Fungicides

These are absorbed by the grass, treating fungus from the inside out. This type is ideal for treating active fungal infections, as it reaches the roots where many diseases take hold. Systemic fungicides can remain effective longer than contact types and provide extended protection.

When to Apply Lawn Fungicide

Applying at the right time can prevent the need for repeated treatments. Due to warm, moist weather, spring and summer are high-risk periods for fungal growth. We recommend applying fungicide in early spring to create a protective barrier and reduce the chances of disease later. 

Preventative vs. Curative

Preventative treatments are most effective when applied before fungi take hold. When to apply preventative fungicide includes when there’s a forecast of prolonged rain or humidity. Curative fungicide, on the other hand, should be used at the first sign of disease to stop its spread.

Best Time of Day to Apply Fungicide

Applying fungicide in the early morning or late evening helps minimize stress on the grass. Fungicides work best when the lawn is damp but not soaked, so early morning with light dew is ideal.

Frequency

Depending on the severity of the infection and the type of fungicide, applications may need to be repeated every two to three weeks. Preventative fungicide generally requires fewer treatments, while active fungal issues may need a more aggressive schedule.

How to Apply Fungicide to Lawn for Best Results

1. Prepare the Lawn: Mow your grass to a standard height and remove any excess thatch; this allows fungicide to penetrate the grass blades and soil more effectively.
2. Apply Fungicide Evenly: Using a spreader for granular fungicide or a sprayer for liquid, cover the entire area and avoid windy days that can lead to uneven application.
3. Water Appropriately: Follow product labels, but avoid overwatering, as excess moisture can encourage fungi.
4. Monitor Lawn Health: If symptoms persist, consider a follow-up application or consult us for further assessment.

Conclusion

Knowing when to put fungicide on your lawn and applying fungicide properly helps keep lawn disease at bay and ensures your yard stays healthy year-round. If you’re uncertain about applying fungicide or need help assessing your lawn, our team is here to support you. Contact Lawn Doctor today for expert advice and personalized lawn care solutions.