Achieve a healthy lawn: The best fertilizers for St. Augustine grass
St. Augustine is a warm season agricultural grass scientifically known as Stenotaphrum secundatum. It has a unique lush, vibrant green color and dense growth and can grow well in humid places. Its leaf structure is flattened and wide, often known as “boat-shaped leaves,” covered with a wiry texture that gives it a coarse appearance. This vigorously growing grass makes a dense carpet like mat in the lawn, which is thick and uniform, making it an ideal choice to enhance the aesthetic appeal of any house lawn.
St. Augustine grass is a resilient choice that stays year-round green and fresh with minimal fertilization. It is a budget-friendly option, especially for beginner growers on a limited budget who wish their lawns looked superb. Well-drained and fertile soils rich in nutrients can multiply the growth of this grass, bringing a sudden but significant change in a lawn through eye-catching greenery, charming views, and a pleasant underfoot cushion.
Without proper fertilization, the grass loses its thickness and beauty, turning its lush green color into yellow, so a stable amount of nitrogen fertilizers is needed to grow this grass with optimal results. Besides fertilizers, regular thatch buildup removal also plays a crucial role in its growth, preventing pest production, nutrient deficiencies, soil fertility, light requirements, and fungal diseases.
Growcycle plays a crucial role in helping the St. Augustine grass growers with specialized tools, products, and high-quality sods and plugs to grow the St. Augustine grass. They guide the optimal soil conditions for the best growth and provide customized fertilizers to maintain the soil conditions suffering from nutrient deficiencies, pH issues, drainage problems, and erosion issues. They also offer multiple sprays tailored to different pests and diseases to ensure St. Augustine grass's health and steady growth.
St. Augustine Grass Nutritional Needs
St. Augustine needs balanced nutrients to grow and prevent pests and disease attacks. These nutrients contribute to its leaf growth and help it thrive during growth. The following are major nutrients for robust growth:
Nitrogen, Potassium, and Phosphorus are fundamental and essential nutrients for grass growth because their role is significant in plant growth and stability. These nutrients improve the drainage properties of soil and prevent loss in waterlogging situations. The deficiency of essential nutrients leads to weak roots and discoloring in grass or leaves of other plants.
The secondary nutrient requirement is less in grass or other plants. Still, their role in growth cannot be minimized as they help in enzyme activation and make the structure of the cell wall healthy, which plays a critical role in chemical reactions. Magnesium is a secondary nutrient, but it plays a significant role in chlorophyll production; sulfur is also a secondary nutrient but a key component of amino acids, active participants in protein synthesis.
Like other grass types, St. Augustine has seasonal variations in nutrient needs, and a comprehensive understanding of these needs helps to improve the required deficiency, which results in optimal growth. This warm-season grass needs rich spring and summer nitrogen for greening up and development; an adequate potassium supply fosters growth and prevents root stress. The supply of nitrogen should be reduced during the fall months. Magnesium and Potassium are helpful for winter preparation because fertilization should stop in cold months, and maximum focus should be on lawn care.
Types of Fertilizers for St. Augustine Grass
Depending upon the grass type, soil condition, nutrient requirements, PH, and climate conditions, multiple fertilizer types can enhance grass growth and improve soil conditions. Some of the top varieties commonly used are the following:
1. Nitrogen Rich Fertilizers
Ammonium sulfate contains 21% nitrogen, and sulfur helps treat alkaline soils and boost grass greenery. It also prevents diseases, especially turf diseases, including take-all root rot. It can be used maximally three times a year, applying one pound of fertilizer per 1000 square feet, but it should be avoided in grass dormant conditions because it is most suitable for the active growing seasons.
Urea has a 46% nitrogen content, a highly concentrated amount that makes it an ideal nitrogen fertilizer for a quick green-up boost for the lawn. It promotes vigorous growth and can be used in granular and liquid forms depending on soil and plant conditions and slow and fast release requirements. Compared to other nitrogen fertilizers available in the market, this one is very budget-friendly and effective.
2. Balanced NPK Fertilizers
Diammonium Phosphate (DAP) is a water-soluble fertilizer rich in nitrogen and phosphorus, with 18% nitrogen and 46% phosphorus. Its neutral nature makes it suitable for broad plants, and its use in St.Augustine grass promotes root health to improve overall health.
Potassium Nitrate has 44% potassium, which helps in enzyme activation, photosynthesis, and water regulation, and 13% nitrogen, which promotes leafy development. In St. Augustine grass, both components help in balanced growth by improving root health foliage and are beneficial for stress conditions.
3. Slow-Release Fertilizers
Polymer-coated urea has a thin layer of polymer that maintains its slow-releasing process. It provides 40% nitrogen that is gradually supplied to the plant. These slow-releasing formulas reduce frequent applications and minimize nutrient leaching. One application in St. Augustine grass can provide a 2-6 month steady nutrition supply.
Sulfur Coated Urea has has 46% nitrogen, and sulfur coating around the granules allows the gradual release of nitrogen to provide steady growth. These fertilizers are ideal for sandy soils, and their application for St. Augustine is productive, requiring continuous nitrogen for better growth.
4. Organic Options
Blood Meal has 12-15% nitrogen, which promotes lush green growth in St. Augustine and improves the overall health of the grass. Still, other nutrients are low in blood meal, so growers must use additional fertilizers to amend the remaining nutrients. The organic structure of blood meal improves water retention, soil structure, and microbial activity.
Feather Meal contains 11-15% nitrogen, released slowly to provide steady growth and prevent nitrogen leaching. Its slow-releasing property and organic nature make it ideal for sandy soils and areas with heavy rainfall. As a nitrogen-rich source, feather meal improves nitrogen availability and provides amino acids, which are the building blocks of proteins.
5. Micronutrient Fertilizers
Iron Sulfate is crucial in St. Augustine for having 20% iron, which helps in photosynthesis reaction and enhances overall growth by making it resilient to disease and pest attacks. Completing the iron needs improves chlorophyll production, and grass gives a pleasant green color. It fights with iron chlorosis, a common disease in alkaline soil, and causes the yellow color of grass.
The leaf tissues between veins turn yellow while the remaining leaf remains green. This situation occurs due to manganese deficiency, which can be restored by manganese sulfate fertilizer. It contains 24-30% manganese, which helps in chlorophyll production and restores the green color. It also helps in metabolic reactions and resists disease in plants; the application in the active season gives more vibrant results than in the dormancy period.
Best Fertilizers for St. Augustine Grass
To ensure optimal growth for St. Augustine grass, it's essential to understand its needs and specific variety before choosing a fertilizer. Here are the top five fertilizers that cater to all types of St. Augustine grass, promoting healthy growth and maintaining soil quality.
1. HiYield 4# Ammonium Sulfate
Hi-Yield 4 Ammonium Sulfate contains 21% nitrogen and 24% sulfur. Nitrogen provides a growth flux that boosts the plant's growth and thickness, making it fuller and healthier in a relatively short time. It also enhances photosynthesis and yields a lush green color.
At the same time, sulfur is essential for soil pH balance and nutrient uptake from roots to shoots. In short, this fertilizer is a quick trick to boost lawn greenery with healthy and resilient plants that survive throughout the year regardless of pests or disease impacts. Spring and summer are the best seasons to apply this fertilizer; it should be used moderately but avoided during plant dormancy.
2. Espoma 4# Urea
Espoma 4 Urea contains a high amount, 45 %, of nitrogen, so besides providing the more profound green color boost microbial activities, it can significantly enhance the health and appearance of St. Augustine grass. It's a quick-release fertilizer that shows immediate results and improves the plant's recovery from environmental stress.
The fertilizer is quite flexible to use, and in addition to St Augustine grass, it can also significantly impact the health and growth of vegetables and flowers. Most importantly, Espoma 4 Urea can be used throughout the growing season, but an optimal fertilizing dose should be no more than 1 lb per 1,000 sq. ft; otherwise, it will negatively impact the grass. This fertilizer is produced eco-friendly and is pure from any filler or impurity, making it a unique and effective product.
3. HiYield 8# Blood Meal 12-0-0
Hi-Yield 8# Blood Meal 12-0-0 is a natural and high-nitrogen fertilizer that can significantly boost plant growth and health for a longer period because of its slow-release effect. This fertilizer reduces the risk of plant burn, which mainly occurs due to sudden quick-release impacts.
It organically boosts soil health, adding more nutrients and strengthening the plant root system when applied no more than 2 lbs per 100 sq. ft. This fertilizer enhances the act of acting as a natural repellent against rabbits and deer and preventing a wide range of diseases. Blood Meal 12-0-0 is very cost-effective, and it is possible to have a lonely and steady nutrient for supernutrient lawn grass.
4. Down To Earth 4# Feather Meal 12-0-0
Down to Earth, 4 Feather Meal 12-0-0 is a specialized organic fertilizer that reduces the nutrients leaching from the soil, leading to nutrient-rich that helps provide steady nutrition to the plant, causing healthy and fast growth. It also enhances microbial activity, which sustains the nitrogen cycle crucial to maintaining a healthy presence of nitrogen in the atmosphere.
It also increases the soil water retention capacity, which is important to store moisture for extended aeration in the soil, which reduces the required water frequency and saves the cost. As this fertilizer is derived from hydrolyzed, dried, and ground poultry feathers, it is a sustainable source of organic fertilizer as a part of the poultry industry. It is also a cost-effective source that ensures long-lasting lawn grass.
5. HiYield 4# Iron Sulfate
Hi-Yield 4# Iron Sulfate is highly effective in treating cirrhosis, a common iron deficiency that leads to leaf yellowing. The iron sulfate fertilizer shows quick results, mostly within a few days, improving the leaf's color and plant health while maintaining the optimal pH levels for St. Augustine grass.
Most importantly, this fertilizer also improves the availability of other nutrients, improves soil aeration, and boosts microbial activities, making it a high-efficiency fertilizer with long-lasting impacts. A proper dosage should not exceed 2-3 ounces per 1,000 sq. ft. to avoid iron toxicity, which is also lethal for plant growth.
When to Fertilize St. Augustine Grass?
St. Augustine's early to mid-spring months are ideal for fertilization because they are a time when grass emerges from dormancy to an active growth period, and nutrient supply improves the growth rate. Slow-release formulas can be used from late spring to mid-summer months to support ongoing growth, and rich-nitrogen fertilizers are ideal for these seasons. The fertilization schedule can be maintained from early to mid-fall because frost days in winter are unsuitable for nutrients, and advanced nourishment helps to continue healthy growth in the off-season.
Extremely hot or cold days are not acceptable for fertilizing the grass because stressed roots slow nutrient absorption, and fertilizers result in runoff. The spring season is ideal when the soil temperature is 65 degrees F and the active period of grass starts. Similarly, applying fertilizers before significant rainfall or with a constant watering schedule helps in rich absorption and prevents runoff.
The frequency of fertilizers can be adjusted according to the grass growth rate or any sign of drought or disease. The yellow or pale green color of leaves, sparse growth, and poor grass density indicate nutrient deficiency. Its result can affect the overall lawn appearance with bare and visible patches. These signs indicate the application of balanced fertilizers.
Tips for Lawn Care
Lawn care techniques vary based on individual lawn needs, but some general tips apply to all lawns, such as:
Proper Mowing
Mowing once a week is necessary to encourage growth in the growing season. The mowing height should adjust according to the grass type, and sharp blades should be used to get clean cuts; dull blades can tear and stress the grass. Preventing the same direction and wet grass for mowing is crucial to preventing disease.
Watering
Grass needs deep watering; hence, it should have 1 inch of water in a single schedule. Morning time is appropriate to prevent evaporation and help maintain deep moisture. The watering frequency should increase on hot days and decrease in cool months.
Aeration and Dethatching
Aeration holes in soil help deepen the penetration of water, air, and nutrients. The aeration process should be performed once per year. Dethatching is a critical process to remove dead roots and grass, which helps in better growth. It should be considered if the dead part exceeds ½ inches.
Custom Fertilizer Blends
When applying customized fertilizers, the fertilizers should be applied according to the lawn’s soil requirements, and the results of a soil test and packaging instructions should be followed.
Pest Management
Regular checking helps examine pest attacks and apply treatments at the right time. Suppose any sign of aphids, insects, or other diseases is found. In that case, treatment should be applied using biological, chemical, or cultural practices, and fertilizers should be used according to accurate ratios and timing.
FAQs
Can I use a general lawn fertilizer for St. Augustine grass?
A general lawn fertilizer can be used for St. Augustine grass, but a specifically formulated fertilizer can promote robust growth. Warm-seasoned grass needs extra nitrogen, so growers should choose customized fertilizers according to their lawn’s specific condition and nutrient requirements.
What should I do if I accidentally overfertilize?
Over-fertilizer can be removed from plants or soil by sweeping with a broom or diluting it by watering the lawn thoroughly. The mowing gap can be extended to allow the grass to grow longer, and it will help the roots absorb more nutrients for photosynthesis.
Are coffee grounds good for St. Augustine grass?
Coffee grounds are beneficial for St. Augustine grass in multiple ways. For example, coffee's nutritional value provides essential nutrients, and soil aeration improves when earthworms in grass roots eat coffee.
The Bottom Line
Fertilizers play a key role in St. Augustine grass growth, promoting a healthy and natural cushion with an eye-catching vibrant green color that enhances the lawn aesthetics and strongly impacts human eyesight. The fertilizers ensure a steady nutrient supply by improving the soil's microbial activities, nutrients, and water retention, leading to plant stress release caused by environmental factors or plants internal chemical reactions. Using the right and customized fertilizers is crucial to get fast and long-lasting results with zero side effects.
Growcycle is one of the top agricultural companies that customizes its services for St Augustine grass growers. They developed tools to help the growers from planting to moving and fertilizing to watering. They also build strong and effective fertilizer formulas tailored to specific grass needs at reasonable costs. Consulting them ensures a lush green lawn with a smooth texture and steady growth throughout the year.
Disclaimer: This material is for informational purposes only and should not be relied on for legal, medical, financial, or other professional advice.
About the Author
Victor Miller 
Environmental Journalist Focused on Sustainable Agriculture
Victor Miller is an environmental journalist at Growcycle, where he covers the latest news, trends, and innovations in sustainable agriculture. He has a deep passion for storytelling that emphasizes ecological balance and responsible farming practices.
Before joining Growcycle, Victor worked for several agricultural and environmental publications, reporting on significant environmental issues and interviewing key figures in the sustainability sector. His work has been featured in various industry journals and online platforms.
