What is the the Best Soil pH for St Augustine Grass?

St. Augustine grass is different from ordinary grass due to the presence of its flat, broad blades. St. Augustine grass (Stenotaphrum secundatum) is a lawn grass that emits a dark green hue. This grass is widespread in many states along the Gulf Coast because it can withstand heat and drought. Are you getting ready to spruce up your landscaping with some St. Augustine grass? Like any plant, soil pH is very crucial even for growing grass.

Thus, if you are wondering what is the best soil pH for St Augustine grass? then we have already done the research and have compiled all the necessary information here in this article, below.  

What is the Best Soil pH for St Augustine Grass?

What is the Best Soil for St.Augustine Grass

St. Augustine grass mostly requires sandy, well-drained soil with a pH of 5 to 6.5. However, the worst kind of soil for this grass is a soggy type of compacted clay soil.

Nevertheless, St. Augustine grass thrives best in sandy soil with a slightly acidic pH. Due to poor oxygen flow, this grass does not grow well on compacted clay soil, and this grass must have access to enough oxygen to enable its growth. Sandy soil is perfect for St. Augustine grass since it has a loose texture and good airflow.

However, some properties of sandy soil may require that you make accommodations. This soil’s looseness makes it easy for water and nutrients to swiftly seep away. Regularly check to make sure your lawn is receiving enough nutrients and water. Sandy soil doesn’t provide a lot of nutrients by itself for your plants or grass. Ensure that your lawn is receiving the fuel it needs to continue growing for another reason.

How do you Raise pH in St. Augustine Grass?

What soil pH is best for St Augustine grass

For St. Augustine grass, a pH of 5.0 to 7.0 is ideal. Phosphorus, a crucial component in the soil, becomes easily accessible within this slightly acidic range. But a well-drained soil type, such as sandy soils, must be paired with the pH range. The nutrients can circulate between the spreading grassroots due to the water movement in the soil pockets, allowing quick absorption.

 A pH metre should be used to check the soil’s pH before sowing or putting St. Augustine seed. Ground Lime should be applied to the soil if the pH is very acidic. Soil acidity will be closer to neutral due to reactions between the lime and soil, allowing nutrients like magnesium to be utilised by the grass. A sulfate-based mixture, such as aluminium sulphate, needs to be added to an alkaline soil, which has a pH level above 7.0. The grass will continue to grow for many years after becoming established in the soil if the pH is brought into the proper range.

So, the easy remedies if your grass displays symptoms of low pH. By applying crushed agricultural limestone to your grass, you can increase the pH level of your lawn. Although slower, dolomitic lime is better for grassroots. Very early spring is also acceptable, fall is the greatest season for spreading lime.

Spread at a rate of 50 lbs. per 1,000 sf of grass, this should raise your pH level by one entire point. Keep in mind that your lawn requires a different pH than your landscape areas, so keep away from areas with trees, bushes, and flowers.

Interesting Tip: Consider spreading lime in the spring and again in the fall if you need to boost that pH by more than one point.

What Fertiliser do I Use on St Augustine Grass? 

For every 1000 square feet of turf, St. Augustine grass lawns should receive 2 to 4 pounds of real nitrogen each growing season. Those planting St. Augustinegrass on sandy soils may opt for the greater pace, while those cultivating lawns on clay soils may opt for the lower rate. In between fertiliser applications, a soluble iron product, such as iron sulphate or commercial chelated iron, can be applied to improve the green colour without promoting growth. As suggested below, St. Augustine grass needs to be fertilised three times during the summer.

  • Early Summer (May):

After the lawn has fully greened up, apply 1/2 to 1 pound of actual nitrogen per 1,000 square feet in early May. The rate is affected by the kind of soil. The need for phosphorous-containing fertiliser can be ascertained through a soil test. To find out how much granular fertiliser should be used, go to the section below on fertiliser calculations.

  • Mid-summer (June through July):

Depending on the soil type, fertilise with 12 to 1 pound of real nitrogen per 1,000 square feet using a strong potassium fertiliser like 15-0-15. In sandy soils, this fertiliser might be very crucial. Only when advised by a soil test can the addition of phosphorus, the middle quantity in the fertiliser analysis, be made.

  •  Late Summer (August): 

Use a high potassium fertiliser, such as 15-0-15, before August 15 to fertilise with 1/2 to 1 pound of real nitrogen per 1,000 square feet, depending on the type of soil. A soil test will be required to ascertain the addition of phosphorous, the middle figure in the fertiliser analysis. Late in the growing season, as the grass enters dormancy, potassium is required for increased disease resistance and winter hardiness. When there is little possibility of a late frost and three weeks after the grass turns green, start fertilising. Apply 1 pound of soluble nitrogen or 11/2 pounds of slow-release nitrogen per 1,000 square feet of lawn every eight weeks or every ten weeks.

  1. Test your soil to see if your grass needs any more fertilisers. Use a complete fertiliser with a 3-1-2 ratio of nitrogen, phosphorus, and potassium if you haven’t had the soil evaluated. Examples are 15/5/10, 21/7/14, etc. (The nutritional analysis is printed on each bag of fertiliser.)
  2. Divide 100 by the first value in the fertiliser analysis to get the amount of fertiliser required to produce 1 pound of nitrogen for every 1,000 square feet. For instance, 6.6 pounds are required per 1,000 square feet if you are using a 15-5-10 fertiliser. (Substitute 150 for 100 to get the amount needed to apply 11/2 pounds per 1,000 square feet.) 100 /15 = 6.6, and (5,000 /1,000) x 6.6 = 33 pounds of fertilizer then figure out how big the area that needs fertilising is. 33 pounds of 15-5-10 fertiliser are needed for a 5,000-square-foot lawn.

How do you Revive St Augustine Grass?  

How do you Revive St Augustine Grass

Giving your lawn 1-1.5 inches of water every week, feeding your soil the right nutrients, and getting rid of any pests or other animals that might be harming your St. Augustine grass are the best ways to revitalise it. There is no reviving your St. Augustine grass if it is dead. Start again, rake up the debris, and plant fresh seeds if you want a healthy lawn. However, it’s possible for your grass to only appear dead for a few weeks while still alive. You may be able to restore these St. Augustine lawns, depending on the cause.

 Determine the cause of the problems your St. Augustine grass is experiencing before you start coming up with solutions. Pests like chinch bugs and grubs, turf diseases like brown patches and grey leaf spots, poor soil quality, and overuse of fertiliser are the main causes.

 There are a few ways to bring your suffering lawn back to its former glory. They are :

  •       Do not disturb your grass by playing on it, parking on it, or letting your dog urinate on it.
  •       Improve The Soil
  •       Proper watering techniques go a long way
  •       Be sure to set your lawn mower in its highest or second-highest setting.


Thus, sandy, loose soils with enough aeration are ideal for St. Augustine grass. The best time to sow this grass is during the warm months, well before the first frost of the year. Before you lay down your sod, your soil needs to be properly prepared and tested.