Should You Treat for Winter Fungus in Florida Lawns?

Understanding Large Patch Fungus in Florida Lawns

If you have St. Augustine grass or Zoysia, large patch fungus is likely showing up in early winter (November/December). In early stages, affected areas often have an orange or pink cast. The patches are irregular and typically follow the flow of water across the lawn.

Why You Should NOT Apply Fungicide for Winter Large Patch

We do NOT recommend applying fungicides this time of year. In fact, using them during fall and winter can actually slow recovery and keep brown patches visible longer.

Here’s why:

• Florida lawns are already growing slowly due to shorter days, reduced sunlight, and cooler temperatures. You’re probably only mowing every 7-10 days.
• Most fungicides used against large patch are growth regulators. They control the fungus by slowing its growth, but they also slow your turf’s growth as a side effect.

Brown patches don’t turn green overnight. Recovery happens when rhizomes and stolons push new blades to replace damaged ones. With growth already limited by weather, adding a growth regulator makes regrowth even slower, meaning those brown spots linger longer.

Better Approach: Feed with Nitrogen to Speed Recovery

Instead of fungicide, continue fertilizing with nitrogen to encourage faster regrowth. Cold weather and short days will naturally keep growth in check, so there’s no risk of it getting out of control. Nitrogen simply helps the grass repair itself more quickly.

Recommended products while the lawn is still active:

• Apply 24-0-6 Flagship or 20-0-2 Derby Green every 30 days
• Continue using Compaction Cure to support stronger regrowth

Once the lawn goes fully dormant, pause applications and resume in spring.

Why “Stop Feeding with Fungus” Advice Doesn’t Apply Here

You might see advice in Facebook groups to “stop fertilizing when fungus is present because it makes it worse.” That guidance usually applies to summer fungus when lawns are growing rapidly. Most people giving that advice aren’t from Florida.

Florida lawn care is different,  especially in the southern part of the state where grass rarely goes fully dormant. Feeding carefully through winter helps recovery without long-term issues.

Alternative: Do Nothing and Wait for Spring

You can also simply let it be. Large patch causes no permanent damage. Come spring, warmer temperatures and longer days will trigger full regrowth, and the lawn will fill in naturally.

Final Takeaway on Winter Fungus in Florida

Skip the fungicide for large patch this season. Focus on nitrogen feeding (while active) to promote faster recovery, or just wait it out. Either way, your St. Augustine or Zoysia will bounce back strong in spring.