Weed-and-Feed Timing for St. Augustine Grass Near Dallas

When to Apply Weed-and-Feed on a Mixed St. Augustine Lawn

A homeowner 60 miles southeast of Dallas has a half St. Augustine, half "sticker" (weedy) lawn and wants to know the best time to apply weed-and-feed.

St. Augustine Green-Up Cues

St. Augustine is a warm-season grass that greens up when night temperatures consistently reach the mid-50s°F. In the Dallas area, this typically coincides with safe tomato planting time outdoors. Do not fertilize until active growth is visible—applying to dormant grass wastes product and risks fungal disease.

Weed-and-Feed Caveats

• Follow label directions exactly—these are salt-based formulas.
• "Too little is better than too much"—over-application burns or kills grass.
• Weed-and-feed products vary: some contain pre-emergent (prevents seed germination), others post-emergent (kills existing weeds). Know which you have.
• For existing weeds, separate fertilizer (ammonium nitrate) from targeted post-emergent herbicide for better control.

Long-Term Strategy

Once weeds are controlled, switch to regular pre-emergent applications to stop new weeds from seed. This is the most efficient, cost-effective path to a weed-free lawn.