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10 Best Fertilizers for St Augustine Grass in Winter 2026

August 4, 2026
Written By jamesmathew

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The biggest mistake people make with winter lawn care is treating their grass like it is still in the middle of a summer growth spurt. St. Augustine grass enters a dormant phase when temperatures drop, meaning it needs a different nutritional approach than it does in July.

Selecting the Best Fertilizers for St Augustine Grass in Winter requires focusing on root development rather than pushing green, leafy growth. Using the wrong formula now can leave your lawn weak and prone to damage when spring finally arrives. Keep reading to see which products actually help your lawn survive the cold.

Key Takeaways

  • Prioritize formulas with lower nitrogen levels to avoid stimulating tender, frost-sensitive growth during cold snaps.
  • Check the label for potassium content, as this mineral helps grass improve its stress tolerance against freezing temperatures.
  • Look for slow-release granules if you want consistent nutrient delivery over several weeks without causing a sudden, unhealthy growth spike.
  • Avoid applying weed control products during peak winter dormancy unless specific weeds are actively growing and causing a nuisance.
  • Consider liquid applications if you need faster absorption, but ensure the soil is not completely frozen when you apply them.

Our Top Best Fertilizers For St Augustine Grass In Winter Picks

Best Overall Choice Sunniland St. Augustine Weed and Feed Sunniland St. Augustine Weed and Feed Dual action weed control Formulated for St. Augustine Convenient all-in-one formula View on Amazon Read Review
Reliable General Maintenance Scotts Turf Builder Lawn Food Scotts Turf Builder Lawn Food Builds deep roots Versatile for any grass Reliable nutrient delivery View on Amazon Read Review
Targeted Winter Nitrogen Sunniland St. Augustine Lawn Fertilizer Sunniland St. Augustine Lawn Fertilizer Slow release nitrogen Phosphorus free formula Designed for St. Augustine View on Amazon Read Review
Heavy Duty Weed Fighter Fertilome St. Augustine Weed and Feed Fertilome St. Augustine Weed and Feed Contains active Atrazine Dual weed control Effective on stubborn weeds View on Amazon Read Review
Best For Color Fertilome High Iron Lawn Fertilizer Fertilome High Iron Lawn Fertilizer High iron content Balanced 15-0-15 ratio Slow release nitrogen View on Amazon Read Review
Fast Absorption Liquid Simple Lawn Solutions Balanced Fertilizer Simple Lawn Solutions Balanced Fertilizer Rapid nutrient delivery Easy spray application Balanced NPK ratio View on Amazon Read Review
Spot Treatment Expert Scotts EZ Patch Repair Mix Scotts EZ Patch Repair Mix Includes mulch and fertilizer Excellent for spot repair Easy to manage View on Amazon Read Review
Best For Runners Liquid St. Augustine Lawn Food Liquid St. Augustine Lawn Food Promotes new runners Fast nutrient delivery High nitrogen boost View on Amazon Read Review
Soil Health Booster Superior Humic and Seaweed Fertilizer Superior Humic and Seaweed Fertilizer Includes humic acid Contains fish and seaweed Integrated sprayer included View on Amazon Read Review
Dandelion Control Specialist Scotts Turf Builder Weed and Feed Scotts Turf Builder Weed and Feed Kills dandelions Eliminates clover Feeds the lawn View on Amazon Read Review

More Details on Our Top Picks

  1. Sunniland St. Augustine Weed and Feed

    Sunniland St. Augustine Weed and Feed

    Best Overall Choice

    View on Amazon

    This is your go-to solution for lawns that need a dual-action approach during the winter transition. It tackles weed control and fertilization in one application, which saves you a significant amount of time in the yard.

    Because it is formulated specifically for St. Augustine, it minimizes the risk of burning your grass. Just keep in mind that this is primarily for established lawns, so avoid using it on freshly laid sod or very young grass.

    • Brand Name:Sunniland
    • Product Type:Weed and Feed
    • Coverage Area:5,000 sq ft
    • Application Form:Granular
    • Additional Feature:Pre-emergent weed protection
    • Additional Feature:Post-emergent weed control
    • Additional Feature:Easy to spread evenly
  2. Scotts Turf Builder Lawn Food

    Scotts Turf Builder Lawn Food

    Reliable General Maintenance

    View on Amazon

    If you prefer a steady, dependable feeding for your lawn, this is a solid choice. It focuses on building strong root systems, which is exactly what St. Augustine needs to survive colder temperatures.

    It covers a generous area, making it efficient for standard suburban yards. Since it is designed for all grass types, it lacks the specific weed-fighting punch of specialized products, so plan accordingly if your weeds are currently out of control.

    • Brand Name:Scotts
    • Product Type:Lawn Food
    • Container Weight:12.5 lbs
    • Coverage Area:5,000 sq ft
    • Application Form:Granular
    • Additional Feature:Promotes lawn thickening
    • Additional Feature:Improves nutrient absorption
    • Additional Feature:Works in all seasons
  3. Sunniland St. Augustine Lawn Fertilizer

    Sunniland St. Augustine Lawn Fertilizer

    Targeted Winter Nitrogen

    View on Amazon

    This product stands out because it offers a slow-release nitrogen source. This is vital in winter because you want the nutrients to feed the soil gradually, rather than dumping them all at once and risking leaching.

    The phosphorus-free formula is a great choice if your local soil regulations are strict or if you simply want to avoid excess runoff. The two-pack setup provides enough volume for larger properties, though it requires a bit of storage space.

    • Brand Name:Sunniland
    • Product Type:Lawn Fertilizer
    • Nutrient Ratio:20-0-6
    • Container Weight:40 lbs total
    • Coverage Area:10,000 sq ft
    • Application Form:Granular
    • Additional Feature:Encourages steady growth
    • Additional Feature:Environmentally conscious composition
    • Additional Feature:Granular delivery method
  4. Fertilome St. Augustine Weed and Feed

    Fertilome St. Augustine Weed and Feed

    Heavy Duty Weed Fighter

    View on Amazon

    When you have a major weed infestation threatening your turf, this granule-based fertilizer is your best friend. The inclusion of Atrazine gives it the muscle needed to kill both emerging and established broadleaf weeds.

    It is particularly effective at maintaining a clean, weed-free appearance through the winter months. Just be careful with your application, as the active ingredient is potent and requires careful spacing to avoid affecting nearby landscape plants.

    • Brand Name:Fertilome
    • Product Type:Weed and Feed
    • Nutrient Ratio:15-0-4
    • Container Weight:12.8 lbs
    • Application Form:Granular
    • Additional Feature:Pre-emergent control
    • Additional Feature:Post-emergent control
    • Additional Feature:Safe for warm-season grasses
  5. Fertilome High Iron Lawn Fertilizer

    Fertilome High Iron Lawn Fertilizer

    Best For Color

    View on Amazon

    Sometimes your grass is healthy but looks a little washed out during the winter. This high-iron formula works wonders to restore a deep, rich green color to your lawn without forcing an unhealthy amount of top growth.

    The 15-0-15 ratio provides a balanced diet of nitrogen and potassium. It acts as a tonic for tired soil, though it will not solve problems related to invasive weed populations.

    • Brand Name:Fertilome
    • Product Type:Lawn Fertilizer
    • Nutrient Ratio:15-0-15
    • Container Weight:16 lbs
    • Application Form:Granular
    • Additional Feature:Deepens grass color
    • Additional Feature:Supports root health
    • Additional Feature:Formulated for warm-season grass
  6. Simple Lawn Solutions Balanced Fertilizer

    Simple Lawn Solutions Balanced Fertilizer

    Fast Absorption Liquid

    View on Amazon

    Liquid fertilizers are perfect for when you need a quick nutrient boost before a cold snap. This balanced NPK formula is easy to spray, allowing for a more uniform application than you might get with a heavy spreader.

    The concentrated spray is incredibly versatile and works well on any grass type. Because it is a liquid, you will need to reapply more frequently than you would with granular options to maintain the same level of soil richness.

    • Brand Name:Simple Lawn Solutions
    • Product Type:Liquid Fertilizer
    • Nutrient Ratio:16-4-8
    • Container Weight:32 ounces
    • Application Form:Liquid
    • Additional Feature:Highly concentrated spray
    • Additional Feature:Works for any grass
    • Additional Feature:Simple hose-end application
  7. Scotts EZ Patch Repair Mix

    Scotts EZ Patch Repair Mix

    Spot Treatment Expert

    View on Amazon

    Winter is the time when you notice those bare patches that survived the summer. This mix is a combination of mulch and fertilizer, designed to help you repair small areas quickly and effectively.

    It is perfect for high-traffic zones or corners where your St. Augustine has worn thin. You should not use this for an entire lawn application, as it is strictly designed for localized repairs in smaller square footage.

    • Brand Name:Scotts
    • Product Type:Repair Mix
    • Container Weight:3.75 lbs
    • Coverage Area:170 sq ft
    • Application Form:Granular mix
    • Additional Feature:Promotes rapid recovery
    • Additional Feature:Pre-mixed for convenience
    • Additional Feature:Ideal for thin grass
  8. Liquid St. Augustine Lawn Food

    Liquid St. Augustine Lawn Food

    Best For Runners

    View on Amazon

    If you are looking to encourage new runners and thicker growth, this concentrated liquid is the right tool. The high nitrogen formula is designed to provide immediate fuel to the grass blades, helping your lawn fill in gaps.

    Its compact size makes it very easy to store, especially if you have a small tool shed. While it excels at boosting surface growth, keep in mind that it provides a short-term burst rather than the long-term sustainability of slow-release granules.

    • Brand Name:Generic
    • Product Type:Liquid Fertilizer
    • Container Weight:8 oz
    • Application Form:Liquid
    • Additional Feature:Supports root growth
    • Additional Feature:Encourages green color
    • Additional Feature:Easy mix and feed
  9. Superior Humic and Seaweed Fertilizer

    Superior Humic and Seaweed Fertilizer

    Soil Health Booster

    View on Amazon

    This liquid fertilizer does more than just feed the blades; it focuses on the underlying soil health. By including humic acid, fish, and seaweed, it helps the soil retain nutrients and moisture during the leaner winter months.

    It is a fantastic all-season product that keeps the biology of your lawn active even when growth slows down. The attached sprayer makes it very user-friendly, though you should ensure your hose pressure is consistent for an even distribution.

    • Brand Name:Simple Lawn Solutions
    • Product Type:Liquid Fertilizer
    • Nutrient Ratio:15-0-15
    • Container Weight:32 ounces
    • Application Form:Liquid
    • Additional Feature:Improves soil structure
    • Additional Feature:Enhances nutrient uptake
    • Additional Feature:Suitable for all grass
  10. Scotts Turf Builder Weed and Feed

    Scotts Turf Builder Weed and Feed

    Dandelion Control Specialist

    View on Amazon

    For homeowners who struggle with dandelion and clover taking over their lawn in the winter, this is a very effective solution. It balances standard fertilizing with targeted weed killers that are safe for most established grasses.

    It covers a large area, which is great for those who want to get the job done in a single afternoon. Be aware that this product is not intended for use on all ornamental landscape plants, so keep the spray away from your flower beds.

    • Brand Name:Scotts
    • Product Type:Weed and Feed
    • Container Weight:14.29 lbs
    • Coverage Area:5,000 sq ft
    • Application Form:Granular
    • Additional Feature:Thickens the turf
    • Additional Feature:Fast-acting weed control
    • Additional Feature:Simple application process

Factors to Consider When Choosing Best Fertilizers For St Augustine Grass In Winter

Nutrient Ratios For Dormancy

St. Augustine grass enters a dormant phase when temperatures drop, meaning it needs very little nitrogen. You should look for a low nitrogen formula, as pushing growth during a cold snap can shock the roots. Prioritize products with higher potassium levels to help the grass survive frost and resist disease.

Potassium For Winter Hardiness

Think of potassium like a winter coat for your lawn. This nutrient regulates the internal water balance of the grass blades, which prevents them from freezing solid when the mercury dips. Choose a fertilizer where the last number on the bag is the highest, such as a 0-0-20 or 5-0-20 blend.

Slow Release Versus Quick

Fast acting fertilizers are a bad idea during the winter because they trigger a growth spurt that the plant cannot sustain. Always opt for slow release nitrogen sources like sulfur coated urea. These release nutrients over several weeks, ensuring the plant receives a steady, gentle feeding rather than a massive dump of chemicals.

Granular Versus Liquid

Granular fertilizers are usually the best choice for winter applications. They sit in the soil and provide a consistent source of nutrients as they break down over time. Liquid fertilizers are often too quick to absorb, which risks burning the lawn if a sudden freeze occurs shortly after application.

Soil pH Compatibility

St. Augustine grass thrives when the soil pH sits between 6.0 and 7.5. If your soil is too acidic or alkaline, the grass cannot absorb the fertilizer you spread. Use a simple test kit to check your levels before applying any product, or your investment might just wash away with the rain.

Application Timing

You want to get your final winter treatment down about four to six weeks before your area usually experiences its first hard frost. This window allows the grass to soak up the potassium and store it in the crown. If you wait until the ground is already frozen, the roots will be too dormant to take up the nutrients.

Frequently Asked Questions

Should I fertilize my St. Augustine grass if it is already brown?

If your lawn is fully dormant and brown, stop applying fertilizer immediately. The grass has effectively shut down its metabolic processes and will not take up any nutrients. Adding more product at this stage will only result in wasted money and potential runoff into the water supply.

Will winter fertilizer make my grass grow faster?

It should not. The goal of winter fertilization is root health and stress tolerance, not top growth. If you see your grass shooting up tall, green blades in the middle of winter, you used a product with too much nitrogen.

How much fertilizer do I actually need to apply?

Follow the application rate listed on the bag for your specific square footage. Most manufacturers suggest applying roughly 0.5 to 1 pound of nitrogen per 1,000 square feet for a winterizing dose. Always calibrate your spreader correctly so you do not leave streaky patches of over-fertilized grass.

Can I use a weed and feed product in the winter?

Avoid using weed and feed products during the cooler months. The herbicides in these mixes often require the grass to be actively growing to work effectively. You are better off applying a dedicated winterizer now and waiting until the spring to address any broadleaf weeds.

Is it safe for my pets if I fertilize in the winter?

Most fertilizers are safe for pets once the granules have been watered into the soil. Check the label for specific waiting times, but usually, a light irrigation cycle will clear the residue from the blades. If you are worried, keep your pets off the lawn until the first heavy rainfall occurs.