St. Augustine grass is one of the most popular lawn types in Texas and throughout the southern United States. Known for its thick blades and rich green color, it creates a beautiful, durable lawn when cared for properly. One of the most important parts of that care is fertilization.
But knowing when and how to fertilize St. Augustine grass can make the difference between a thriving lawn and one that struggles. Here’s everything you need to know to keep your St. Augustine looking its best.
Understanding the Growth Cycle of St. Augustine Grass
Before applying any fertilizer, it’s important to understand how St. Augustine grass grows throughout the year.
As the experts at JC’s Landscaping explain:
“St. Augustine grass enters dormancy during the winter months like other warm-season grasses. Dormancy is a natural survival response triggered by shorter days and lower soil temperatures.”
Because of this natural cycle, fertilizing at the wrong time can be ineffective—or even harmful. Learning how your grass behaves in winter is key to planning a smart fertilization schedule. To better understand what happens to your lawn in the colder months, be sure to read the full guide on St. Augustine grass in winter.

When to Fertilize St. Augustine Grass
Timing is everything when it comes to lawn fertilization.
Early Spring (First Application)
The best time to begin fertilizing St. Augustine grass is in early spring—after the lawn has fully greened up. Applying fertilizer too early, while the grass is still coming out of dormancy, can encourage weed growth instead of healthy turf.
Wait until:
- Soil temperatures have warmed
- The lawn is actively growing
- There is no longer a risk of frost
For most North Texas lawns, this is typically around late March to early April.

Late Spring to Summer (Main Growing Season)
St. Augustine grass grows most actively from late spring through summer. During this period, it benefits from regular feedings to maintain color and thickness.
A good rule of thumb is to fertilize every 6–8 weeks during the growing season using a slow-release, nitrogen-rich fertilizer. This helps:
- Promote deep green color
- Encourage strong root development
- Improve overall lawn density
Fall (Final Application)
One last light fertilization in early fall can help your lawn recover from summer stress and prepare for winter dormancy.
Avoid heavy fertilizing late in the season, as pushing new growth right before winter can weaken the grass.
Winter – Skip the Fertilizer
Since St. Augustine grass goes dormant in winter, it does not need fertilizer during the colder months. Feeding a dormant lawn won’t help and can even lead to disease or unnecessary runoff.
How to Fertilize St. Augustine Grass
Applying fertilizer correctly is just as important as choosing the right time.
Choose the Right Fertilizer
Look for a fertilizer specifically formulated for St. Augustine grass or warm-season lawns. These blends are designed with the proper balance of:
- Nitrogen for green color
- Potassium for strength
- Micronutrients for overall health
Slow-release formulas are best because they feed the lawn gradually instead of all at once.
Apply Evenly
Uneven fertilizer application can lead to streaks, burned patches, or inconsistent color. Use a broadcast spreader and follow label instructions carefully.
Always:
- Measure your lawn area
- Use the recommended rate
- Avoid overlapping passes
Water After Fertilizing
Watering after fertilization helps move nutrients into the soil and prevents grass blades from burning. A light watering immediately after application is ideal.
Additional Tips for Best Results
Fertilizer works best when combined with proper overall lawn care:
- Mow at the correct height (about 3–4 inches for St. Augustine)
- Water deeply and infrequently
- Aerate compacted soil
- Address weeds and pests promptly

A well-rounded lawn care program will help your St. Augustine grass make the most of every fertilizer treatment.
When to Call the Professionals
If you’re unsure about which fertilizer to use or how often to apply it, professional lawn care can take the guesswork out of the process.
Over-fertilizing, under-fertilizing, or using the wrong product can damage your lawn. A customized fertilization plan ensures your St. Augustine grass gets exactly what it needs—at the right time of year.
JC’s Landscaping – Lawn Care Experts in North Texas
For professional fertilization and year-round lawn care services, trust the team at JC’s Landscaping.
JC’s Landscaping
Address: 6401 Eldorado Pkwy, Suite 305
McKinney, TX 75070
Phone: (972) 564-8284
Website: https://www.jclandscapingllc.com/
Their experienced lawn care specialists can help keep your St. Augustine grass healthy, green, and thriving in every season.
Fertilizing St. Augustine grass doesn’t have to be complicated. With the right timing, techniques, and a little expert help, you can enjoy a lush, vibrant lawn all year long.

