- Lime and fertilizer called for by a soil test belong in the soil before the sod goes down, mixed into the top few inches.
- LSU AgCenter recommends up to 0.5 pound of nitrogen per 1,000 square feet once the new sod has rooted into the soil.
- Rooting can take 30 to 60 days depending on conditions, so a gentle tug test tells you when it’s time.
- For established St. Augustine, LSU caps each application at 1 pound of nitrogen per 1,000 square feet.
- Avoid nitrogen late in the season, since LSU links late feeding with more brown patch in the fall.
- Before the sod: fertilize the soil, not the grass
- After the sod: wait for roots
- How to tell the sod is ready
- How much fertilizer to use
- Step-by-step: the first feeding
- Timing through the Louisiana year
- Why feeding too early causes problems
- Common fertilizing mistakes with new sod
- Pale sod isn't always hungry sod
- The first year of feeding
- Frequently asked questions
The new sod looks a little pale after the first couple of weeks, and the bag of lawn fertilizer in the garage is tempting. Feeding too early can burn tender roots and push soft growth that invites disease, while feeding at the right moment helps the lawn knit in and thicken. The timing depends less on the calendar than on what’s happening under the sod.
At TurnKey Lawn Care, sod installation and the feeding that follows are part of the work we do across the metro. If you’ve just put in a new lawn, request a free estimate and we’ll plan the first year of feeding with you.
This guide covers what goes into the soil before sod, when the first feeding should happen, how much to use, the seasonal timing that matters in Louisiana and the mistakes that set new sod back.
Before the sod: fertilize the soil, not the grass
The first feeding for a new lawn happens before any sod arrives. An LSU AgCenter article on starting a southern lawn advises adding fertilizer and lime as indicated by a soil test after the topsoil is spread and graded, and thoroughly mixing them into the top 3 inches. Clemson Extension gives similar advice, recommending that fertilizer and lime based on soil test results be worked into the upper 4 to 6 inches before installation. Placing nutrients in the soil puts them where the new roots will grow. Scattering fertilizer on top of freshly laid sod doesn’t do the same job, because the roots haven’t reached the soil yet.
After the sod: wait for roots
Once the sod is down, the priority is water, not fertilizer. The LSU AgCenter home lawn series recommends watering one to two times a day for the first 10 to 14 days while the sod roots in. The same series recommends applying up to 0.5 pound of nitrogen per 1,000 square feet when the turfgrass has rooted into the soil. That’s a light feeding, about half the maximum LSU allows for a single application on established St. Augustine. LSU notes that roots may appear within 30 to 60 days depending on conditions. That range is why the tug test matters more than a fixed number of days.
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How to tell the sod is ready
Use a gentle tug on a corner of a sod piece to judge rooting:
- Lifts freely: the roots haven’t reached the soil, so hold off on fertilizer
- Resists slightly, with white roots visible: rooting has started, so keep watching
- Holds firm across the lawn: the sod has rooted in, and a light feeding is appropriate
Check several spots, including edges and seams, which often root last. If the middle of the lawn is firm but the edges still lift, give it a little more time.
How much fertilizer to use
The first feeding on new sod should be light. Here’s how LSU’s figures compare for new and established St. Augustine:
| Situation | LSU nitrogen guidance |
|---|---|
| New sod, once rooted | Up to 0.5 pound per 1,000 square feet |
| Established St. Augustine, per application | No more than 1 pound per 1,000 square feet |
| Established St. Augustine, per year | Up to 3 pounds per 1,000 square feet |
Fertilizer bags list their nitrogen content as the first number on the label. The bag directions show how much product to spread to deliver a given amount of nitrogen, and a calibrated spreader keeps the rate even. Our guide to the best fertilizer for St. Augustine explains how to read the label and choose a product.
Step-by-step: the first feeding
- Confirm rooting. Tug-test the sod in several places, including the edges.
- Check the season. Make sure you’re not heading into late summer or fall, when LSU cautions against extra nitrogen.
- Measure the lawn. Calculate the square footage so you can apply the right amount.
- Set the spreader. Follow the bag directions to deliver no more than 0.5 pound of nitrogen per 1,000 square feet.
- Spread on dry grass. Apply when the blades are dry so granules don’t stick and burn the leaves.
- Water it in. Irrigate lightly afterward, as the label directs, to move the fertilizer into the soil.
Timing through the Louisiana year
When the sod was laid affects when the first feeding should happen. LSU’s home lawn series notes sod can be established year-round but is more prone to drying out and winter injury while dormant, from October to March.
- Spring sod: roots in as the weather warms, and the first light feeding usually falls in late spring or early summer
- Summer sod: grows quickly in the heat, and a light feeding once it’s rooted supports that growth
- Late summer and early fall sod: skip the nitrogen and let it root in, then feed the following spring
- Winter sod: dormant grass doesn’t use fertilizer, so wait for spring green-up
The late-season caution comes from LSU. An LSU AgCenter article on late-summer lawn care advises avoiding nitrogen fertilizer after mid-August, because it may lead to more brown patch disease. LSU’s fall lawn guidance adds that excess nitrogen late in the year stimulates tender growth when the lawn should be preparing for dormancy.
Why feeding too early causes problems
New sod has almost no roots in the soil for the first couple of weeks. Fertilizer spread on top at that stage mostly sits on the sod or washes through with the frequent watering, and a heavy dose can burn the grass. It can also push the wrong kind of growth. Nitrogen encourages soft, lush leaves, and new St. Augustine that’s being watered once or twice a day is already prone to disease. An LSU AgCenter guide to sod cautions that St. Augustine is particularly susceptible to large patch and gray leaf spot, especially with overwatering, and lush growth adds to that risk. Roots first, then a light feeding, keeps the new lawn putting its energy into anchoring rather than into soft top growth. A lawn that roots deeply in its first season is also better prepared for summer heat, dry spells and the pests that target stressed St. Augustine.
Common fertilizing mistakes with new sod
- Spreading fertilizer on the day of installation instead of mixing it into the soil beforehand
- Feeding before the sod has rooted, while it’s still being watered daily
- Using a full-strength application instead of LSU’s lighter 0.5-pound first feeding
- Using a weed-and-feed product on new sod without checking whether the label allows it
- Pushing nitrogen in late summer or fall, when LSU cautions it can increase brown patch
- Skipping the soil test and adding lime or nutrients the soil doesn’t need
Weed-and-feed products deserve their own warning. They combine fertilizer with herbicide, and many herbicide labels restrict use on newly installed turf. Check the label, and when in doubt, fertilize and control weeds separately until the lawn is established. A few weeds in new sod can be pulled by hand far more safely than a new lawn can be sprayed.
Pale sod isn't always hungry sod
A new lawn that looks a little pale in the first weeks is the most common reason people reach for fertilizer too soon. Often the color has nothing to do with nutrients. Several things make new sod look washed out:
- Stress from being cut, stacked and moved, which the grass recovers from as it roots
- Too little water at the edges and seams, where sod dries first
- Too much water, which keeps the roots short and the soil waterlogged
- Soil pH or nutrient problems that fertilizer alone won’t fix
Check the watering and the rooting before assuming the lawn needs feeding. If the soil test before installation showed a problem, correcting it in the soil matters more than adding nitrogen on top. Our post on preparing soil for sod in Louisiana covers those pre-planting steps.
The first year of feeding
After that first light feeding, new sod moves onto a normal program for its grass type. For St. Augustine, LSU recommends up to 3 pounds of nitrogen per 1,000 square feet per year, with no more than 1 pound per application, guided by a soil test. Our page on when to fertilize a lawn in Louisiana lays out the seasonal schedule, and our lawn fertilization service handles it for you if you’d rather not track it. Our posts on how often to water new sod and when to mow new sod cover the other parts of the first weeks, and our sod installation guide covers the process from start to finish.
Frequently asked questions
When should I fertilize new sod?
Once it has rooted into the soil. LSU AgCenter recommends up to 0.5 pound of nitrogen per 1,000 square feet at that point, and notes rooting can take 30 to 60 days depending on conditions, so use a tug test rather than a fixed date.
Is it better to fertilize before or after laying sod?
Both have a place. Lime and fertilizer called for by a soil test go into the soil before installation, mixed into the top few inches, and a light nitrogen feeding follows after the sod has rooted.
What is the best fertilizer to put on new sod?
A lawn fertilizer applied at a light rate, delivering no more than 0.5 pound of nitrogen per 1,000 square feet for the first feeding, as LSU AgCenter recommends. A soil test shows whether the lawn also needs phosphorus, potassium or a pH adjustment.
Can I use weed and feed on new sod?
Check the label first, since many herbicide labels restrict use on newly installed turf. The safer approach is to fertilize and control weeds separately until the new lawn is established.
Should I fertilize new sod in the fall?
Generally not with nitrogen. LSU AgCenter advises avoiding nitrogen after mid-August because it may increase brown patch, so fall-laid sod is best left to root in and fed the following spring.
Plan the first year of feeding
Tell us when your sod was laid and what grass it is. We’ll check the rooting, set up a feeding schedule that fits the season and give you a free estimate before any work starts, with the price agreed up front.
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