Best Fertilizers for St Augustine Grass in 2026 [Top Expert Picks]

Scotts Turf Builder Southern Lawn Food is a classic go-to for anyone looking to feed southern grass types like St Augustine. It’s pesticide-free, making it safer for pets and kids, and covers a generous 10,000 square feet in one application. What stands out is its formulation with Scotts All-in-One Particles that help build deep, strong roots, which is essential for heat and drought resistance.

I’ve found this fertilizer performs especially well when applied during the growing seasons of spring and summer. The instructions to lightly water it in right after application really make a difference in quick nutrient absorption. Compared to some slow-release options, Scotts gives a faster green-up, which is great if you want visible improvements without waiting weeks.

While it covers a large area, it’s perfect for medium to large lawns where you want a reliable, straightforward lawn food without any complex additives. It’s definitely a solid foundation fertilizer if you’re just starting a lawn care regimen.

If rich, deep green color is what you’re after, SeedRanch’s 24-2-11 formula with 6% iron really shines. This fertilizer is tailored for St Augustine lawns and offers a balanced nutrient profile that promotes vibrant turf appearance alongside healthy growth.

In my experience, the iron content noticeably enhances the lawn’s color, especially during the growing season when your grass needs that extra boost. It covers 12,000 square feet, so it’s a great value for larger lawns. Compared to other fertilizers without iron, this one gives the lawn a lushness that’s hard to miss.

It’s also straightforward to apply and works well when combined with regular watering. If your lawn is looking a little dull, this fertilizer could be just what it needs to bring back that eye-catching green.

Slow-release nitrogen is a game-changer for steady lawn feeding, and Sunniland’s 20-0-6 fertilizer nails this with 50% slow-release nitrogen. Designed specifically for St Augustine grass, it supports consistent growth and a healthier appearance throughout the season.

I liked how the phosphorus-free formula caters to lawns that don’t need a phosphorus boost, reducing the risk of over-fertilizing. The even granular spread made application easy with my drop spreader, and since it covers 5,000 square feet per bag, the two-pack is handy for multiple treatments or larger yards.

This one felt gentler on the lawn compared to fast-release options, meaning less chance of burning and more even growth. If you prefer a low-maintenance feeding schedule, this fertilizer is a solid choice.

For those who want quick, visible results, liquid fertilizers like this 32 oz product from TPS NUTRIENTS offer fast absorption and a noticeable boost in lawn color and thickness. It’s designed to promote new runners and richer green shades, which is fantastic for a lively lawn.

I found that the liquid format allowed for targeted application, which is handy for spotting areas that need extra help. It also helps build stronger roots, enhancing the turf’s resistance to heat and wear. Compared to granular fertilizers, this one works faster but requires more frequent application.

If you prefer a liquid feed that’s easy to use and want your lawn to look vibrant quickly, this is a great pick. Just keep in mind it’s more of a supplementary fertilizer than a full-season solution.

This liquid fertilizer offers a balanced 16-4-8 NPK ratio enriched with seaweed and fish emulsion, which adds organic matter to your soil. I appreciated this because it not only feeds your grass but also improves overall soil health, something that granular fertilizers often miss.

It’s suitable for St Augustine and many other grass types, making it versatile. During my trials, I noticed it encouraged vigorous growth and lush green color without overdoing nitrogen. The inclusion of potassium helps with drought and temperature stress, which is a big plus for southern lawns.

While it’s a liquid fertilizer like the TPS NUTRIENTS product, this one felt more comprehensive for ongoing lawn maintenance and boosting both root and shoot growth.

Preparing your St Augustine lawn for winter is crucial, and The Andersons’ 24-0-14 formula is designed just for that. It combines quick, intermediate, and slow-release nitrogen with iron to boost deep greening and strength before dormancy.

I found this fertilizer especially effective in late fall, helping my lawn store nutrients and recover from summer stress. The iron component adds a rich green color even as temperatures drop. It’s also safe for all turf types, which is reassuring if you have mixed grasses.

Compared to summer fertilizers, this one feels more focused on resilience and winter prep, so keep it in your rotation for seasonal care.

This premium granular fertilizer from The Andersons offers a perfect 16-4-8 NPK ratio with added humic substances for enhanced nutrient uptake and soil vitality. The super-fine particles ensure even application, which I noticed makes a visible difference in uniform lawn health.

It includes both quick- and slow-release nitrogen, giving immediate greening effects while sustaining growth for up to eight weeks. The added iron and micronutrients support rich color and overall turf vigor, making it a great choice if you want high-performance results.

While it’s on the pricier side and not available in California, this fertilizer feels like a professional-grade product that can really elevate your St Augustine lawn care routine.