Once your new St. Augustine sod takes hold and starts growing, you will need to begin feeding it. But before heading to the garden supply store to grab a bag of fertilizer, you will have to grab your calculator and calendar first. Even though your new St. Augustine sod needs to be fed, you still have to follow the rules set in place by your State, County, and City. So, before you rush into fertilizing, let’s look at all the different elements that make up a fertilizing schedule and what considerations you need to make.
When to Fertilize New St Augustine Sod? (The Short Answer)
Fertilizing new St. Augustine sod should be done no earlier than 30 days after planting. Before fertilizing, you need to make sure that the new sod has rooted into the soil and is in good health. Additionally, you must follow City, Country, and State regulations, including location, blackout dates, and annual fertilizer limits.
Fertilizing Schedule Restriction for New St. Augustine Sod
The first thing you need to do when working out a fertilizing schedule is to check the rules and limitations set in place by your local and state authorities. This means that your new St. Augustine sod needs to fit into an ongoing annual schedule. So, let’s take a closer look at the items that determine your new fertilizing schedule.
Which Rules to Follow, City, County, or State
Once you start looking for which sets of rules to follow, you’ll see that there are different regulations for city, county, and state. So which do you follow? Well, you will likely see that the state is more lenient than the city since individual cities increase restrictions to best suit their local ecosystems. I recommend checking all of the regulations, but you will probably find the city is the same as the state or stricter.
Blackout Date
Fertilizers containing nitrogen and phosphorus in places such as Florida can’t be used during certain parts of the year. This blackout date is roughly between June 30th to October 1st due to the rainy season. Daily rain or near-daily rain washes the surface and deposits any chemical pollutants such as nitrogen and phosphorus into the waterways, causing extensive damage to aquatic ecosystems.
So, if new St. Augustine sod needs to be fed during these blackout periods, you can’t use a fertilizer that contains nitrogen or phosphorus. Unfortunately, a fertilizer with nitrogen and phosphorus is what your new sod wants. But don’t worry, I will tell you a way to work around this.
Nitrogen Annual Limit
The next restriction you’ll have to account for is the amount of nitrogen you can apply to any singular space within one calendar year. For example, some areas in Florida have a limit of 4lbs of nitrogen per 1000 square feet in one calendar year.
Nitrogen Content Application Limit
To make things even more complicated, local authorities limit the amount of nitrogen content within the fertilizer you use. Using Florida again as an example, some areas limit the nitrogen content in fertilizer to 20%. So, if you pick up a bag of fertilizer N-22 written on the side, then you will be breaking the law if you use it because the 22% nitrogen content is over the city’s restriction.
Total Nitrogen Application per Single Application Limit
The following restriction deals with how much nitrogen you can use at one time. Again, local authorities limit how much nitrogen you can spread per 1000 square feet in a single application. So, you could face limits such as 1lb per 1000 square feet.
Total Nitrogen Application per Year
You’re probably starting to think that there are a lot of rules when it comes to fertilizing your lawn. Unfortunately, there are still a lot more rules that will determine your fertilizing schedule for your new St. Augustine sod. The next restriction limits how many times you can actually fertilize in the year during non-blackout periods.
So, using this same example:
- 4lb/1000ft2 per year
- 1lb/1000ft2 per application
This means you can use a total of four applications to completely spread the 4lb annual limit. But you will likely find that your city has a limit of more applications per year than just four. So, all you need to do is divide the max nitrogen per year limit by the applications per year, and you will find out how much you can spread per application. Here is an example:
- 4lb/1000ft2 per year ÷ 6 maximum application per year = 0.66lb/1000ft2 per application.
This example indicates you can have between 4 and 6 applications and still stay within the requirements. I told you you would need a calculator.
Slow Release Fertilizer Nitrogen Minimum
Slow release fertilizer (SRF) is fertilizer that releases its content over a long period. Usually, it can take up to two months or so for the granular fertilizer to dissolve completely. This means you can still fertilize the lawn even during the blackout dates. Within the city fertilizing ordinance, you’ll see a requirement such as a 50% slow-release minimum, meaning that half of the fertilizers you need to use are slow-release.
Phosphorus Limits
Just like nitrogen limits, phosphorus is also limited. So, if you see that the phosphorus limit in your area says 2% phosphorus, you’ll need to make sure that the fertilizer you use doesn’t exceed this maximum.
Factors that May Affect When You Should Fertilize Your New St. Augustine Sod
Now that you are aware of the unavoidable restrictions set in place by local authorities, you’ll see that you have several months available to fertilize. But, there are still some additional considerations you should be aware of. Let’s take a look at what these are.
Weather During Allowed Fertilizing Periods
Knowing when to fertilize new St. Augustine sod in Texas has the same varying factor as knowing when to fertilize new St. Augustine sod in Florida. This common factor is the weather difference from the north to the south.
Texas stretches nearly 1000 miles from top to bottom, whereas Florida stretches almost 450 miles. For example, if you are in Corpus Christi in Southern Texas, you rarely get a frost, whereas in Amarillo, in Northern Texas, frost rolls in mid-November. This is very similar in Florida. Key West stays pretty warm throughout the year, whereas Tallahassee experiences a significant temperature drop and commonly faces frosts during winter.
So, if you live in the Northern areas of these states, you need to plan and lay your last fertilizer at least six weeks before the first frost. You shouldn’t fertilize if you have new St. Augustine sod during the frost cut-off.
Because of these considerations, your fertilizing schedule needs to be very specific to where you live. Using a generic schedule can end up doing more harm than good.
Waiting for the Grass to be Active
One thing you don’t want to do is spread fertilizer on dormant grass or new sod. So, you must wait for the grass to grow and complete the first few cuts. In the case of sod, you need to wait until it has rooted and is growing. Once you look at your schedule, you’ll quickly notice that a lot of the year is blacked-out because of city rules, frost, waiting for the grass to become active, and waiting for new sod to root.
Gap Between Applications
The next consideration on the list is how long you should wait between applications. Fertilizers with slow release should last between 6-8 weeks. So, leaving a gap of two months between applications should work fine. Also, overfertilizing weakens and stunts plants, making them susceptible to disease and pests. So if you have the sod on ground that’s already been fertilized, you could risk over-fertilizing.
Fertilizing Schedule for New St. Augustine Sod
With all this information, you can finally start to put together your schedule and figure out when to fertilize new St. Augustine sod. Here is an example I’ve used to show how to put together a fertilizing schedule. In this example, I have chosen to use Sanibel, Florida.
Schedule for Fertilizing New St. Augustine Sod
First, cross out the periods when you can’t and don’t want to fertilize. This includes the dates when regulations say you can’t and when weather and growing patterns say you shouldn’t. Then you need to work out how to spread the applications over the available period.
So, let’s look at Sanibel.
As Sanibel is only restricted by city regulations and not the weather, the blackout period is only between June 30th and October 1st. This equals 13 weeks of blackout and 39 weeks of available fertilizing time. In addition, Sanibel has a single application limit of six applications, which means you can fertilize every eight weeks (two months) apart from your last application before the blackout starts. This fits in the available period, and the slow release will keep feeding the St. Augustine all year, apart from the five weeks at the end of the cutoff.
So, after gathering all this information and making your calculations, you’ll see that if you already follow a proper fertilizing schedule, there is no need to fertilize your new sod because the soil already has the necessary nutrients available. However, if you’re not already following a schedule, then as long as you’re not in the blackout period, wait at least four weeks before fertilizing your new St. Augustine sod.
Here’s what this example would look like in table form:
| Month | Blackout Periods | When to Apply |
|---|---|---|
| January | Fertilizer Application January 22nd | |
| February | ||
| March | Fertilizer Application March 19th | |
| April | ||
| May | Fertilizer Application May 14th | |
| June | Fertilizer Application June 29th | |
| July | Blackout | |
| August | Blackout | |
| September | Blackout | |
| October | Fertilizer Application October 2nd | |
| November | Fertilizer Application November 27th | |
| December |
Advice for Fertilizing New St. Augustine Sod
I’m a firm believer in taking the guesswork out of any situation; this includes whether you should fertilize new St. Augustine sod. So, here are a few tips for fertilizing your new sod.
Soil Testing
The easiest way to determine what fertilizer you need or even how much to use is to have your soil tested. A comprehensive soil test will tell you exactly what your lawn needs and if it has too much of something. So, before you spend your money on fertilizer, check what you actually need.
Have A Fertilizing Schedule Before You Lay Sod
Calculating a schedule is a good idea if you haven’t already laid your sod or have just done it. A fertilizing schedule will answer any questions regarding whether or not you should or shouldn’t fertilize. Also, making a schedule with a soil test in hand will help you figure out when to fertilize.
Apply for a Special Fertilizing Permit
Now, if you find that you really need to fertilize your new St. Augustine sod and you’re within the restricted period, then you could try to call your local city and ask if they offer a special fertilizing permit. A number of states provide fertilizing permits that will get you around the restrictions.
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