Why Does My Lawn Look Dead After a Cold Snap in Tampa Bay?

Every winter, St. Pete homeowners panic when their lush green lawn turns brown after a cold front rolls through. Before you start calling landscapers for re-sod quotes, here is what is actually happening — and why you probably do not need to do anything dramatic.

What Happens to St. Augustine Grass in the Cold

St. Augustine grass is a warm-season grass that goes dormant when soil temperatures drop consistently below 55°F. In St. Petersburg, this typically happens during cold fronts from December through February. When dormant, it stops growing and turns brown or straw-colored.

This is not dead grass. The roots and stolons are alive underground. As soon as temperatures warm — which in St. Pete often happens within days — the grass greens back up and begins growing again.

Dormant vs. Dead — How to Tell

• Dormant: Browning is uniform across the lawn; stolons are still light tan or green; turf is firm and attached; grass greens up within 1–2 weeks of warm weather.
• Dead: Stolons are dry and pull away easily from soil; turf lifts like a mat with no root resistance; damage is patchy and corresponds exactly to exposed vs. sheltered areas.

For St. Pete, true freeze damage (where roots die) only occurs after extended periods of 28°F or below — which is relatively rare. A typical overnight cold front into the low 40s will not kill established St. Augustine roots.

What NOT to Do After a Cold Snap

• Do not fertilize immediately. Applying nitrogen to dormant grass — especially before the last frost risk — can stimulate new tender growth that gets hit by the next cold front.
• Do not mow aggressively. Brown dormant grass does not need cutting. Leave the deck up.
• Do not increase irrigation. Dormant grass uses very little water. Overwatering promotes fungal disease.
• Do not re-sod yet. Wait until March or April to assess what is truly dead vs. dormant. Most homeowners who re-sod in January regret it when the old grass comes back green in March.

When to Be Concerned

If it is late March and your lawn still has not greened up while neighbors' lawns have, you may have true freeze damage. A visual inspection of the stolons and a tug test will tell you whether you need to spot-repair or re-sod sections.