Lawn Fertilizer Schedule by Season and Grass Type
A reliable fertilizer schedule matches nitrogen delivery to the active growth periods of your grass type. The wrong timing, applying to dormant grass, fertilizing in summer heat, or skipping the fall window for cool-season turf, reduces the benefit of each application and can actively damage the lawn. This schedule covers the full year for both cool-season and warm-season grasses with specific timing windows, recommended NPK ratios, and nitrogen rates for each application.
Cool-Season Grass Fertilizer Schedule
Cool-season grasses. Kentucky bluegrass, tall fescue, fine fescue, and perennial ryegrass, have two active growth periods: spring (roughly March through May) and fall (September through November). Summer is a period of reduced growth and stress for these grasses. The fertilizer schedule reflects this pattern.
Spring Application (Mid-Spring. April to May)
When: Once the lawn has fully greened up and been mowed two to three times. Soil temperature should be above 50 degrees Fahrenheit.
Why: Supports the spring growth flush without driving excessive shoot growth at the expense of root development. Applying too early (before the lawn is actively growing) wastes product. Applying too late in spring, as summer approaches, risks applying nitrogen when the turf is about to enter heat stress.
Recommended NPK: 24-0-6 or 28-0-3. Moderate nitrogen, no phosphorus (unless a soil test confirms deficiency), low to moderate potassium.
Nitrogen rate: 0.5 to 0.75 pounds of actual nitrogen per 1,000 square feet.
Nitrogen type: Slow-release (50% or higher slow-release content). Avoids the flush-and-crash growth pattern of quick-release spring applications.
Late Spring / Early Summer (Optional. May to June)
When: Only if the lawn is actively growing and visibly nitrogen-deficient. Skip this application if the spring application used a slow-release product and the lawn is still green and growing.
Why: Some homeowners on a four-application schedule include a light late-spring feeding, but for most cool-season lawns this application is not necessary and increases summer growth at a time when the lawn benefits from slowing down.
If applying: Use a light rate, 0.25 to 0.5 pounds of actual nitrogen per 1,000 square feet with a slow-release source.
Summer (June through August). Generally Skip
Recommendation: Do not apply high-nitrogen fertilizer to cool-season turf during the heat of summer. Heat-stressed turf cannot effectively use nitrogen, and soluble nitrogen salts at the root zone increase drought stress.
Exception: A very light application of organic nitrogen (Milorganite at half the normal rate) can be made during summer if the lawn is well-irrigated and not showing heat stress. This provides enough nutrition to maintain color without forcing the growth surge that synthetic nitrogen would produce.
Early Fall (September. Most Important Application)
When: Early to mid-September in most cool-season regions. Soil temperature should be dropping below 75 degrees Fahrenheit, and daytime temperatures should be regularly below 85 degrees Fahrenheit.
Why: This is the single most important fertilizer application of the year for cool-season turf. Grass recovering from summer stress is entering its most active root growth period of the year. Nitrogen applied now drives root development, thickens the turf canopy, and builds carbohydrate reserves for winter survival. Lawns that receive a strong fall application green up earlier and more vigorously the following spring.
Recommended NPK: 28-0-10 or 32-0-10. Higher potassium than the spring application to support winter hardiness and root development.
Nitrogen rate: 0.75 to 1.0 pounds of actual nitrogen per 1,000 square feet.
Nitrogen type: Combination slow-release and quick-release. A portion of quick-release nitrogen ensures the lawn benefits before temperatures drop further. The slow-release fraction continues feeding through October.
Late Fall (October to November. Winterizer)
When: After the lawn’s growth rate has slowed significantly but before the ground freezes. Typically October to early November in the northern US.
Why: The late-fall or “dormant” application delivers nitrogen that is taken up by turf roots even as top growth slows. The nitrogen is stored as amino acids and proteins in root tissue and crowns, providing the fuel for the initial spring green-up when soil temperatures rise. Lawns that receive a late-fall application green up faster and more evenly in spring than lawns that skip this step.
Recommended NPK: 32-0-6 or similar, quick-release nitrogen acceptable here since the goal is uptake for storage rather than driving growth.
Nitrogen rate: 0.5 pounds of actual nitrogen per 1,000 square feet. Light rate only, no benefit to a heavy application when growth has slowed.
Warm-Season Grass Fertilizer Schedule
Warm-season grasses. Bermuda, Zoysia, St. Augustine, and Centipede, grow actively from late spring through summer and go dormant in fall and winter. Their fertilizer schedule is the seasonal inverse of cool-season timing.
Early Spring. Do Not Fertilize
Wait until the grass has fully broken dormancy and is at least 50% green before applying any fertilizer. Applying nitrogen to dormant or partially dormant warm-season turf pushes top growth before the root system is active enough to support it, and can increase vulnerability to a late frost on the new growth.
Late Spring (First Application. May to Early June)
When: Lawn is fully green and actively growing. Daytime temperatures consistently above 70 degrees Fahrenheit.
Recommended NPK: 20-0-8 or 24-0-10. Moderate nitrogen, higher potassium than a cool-season spring product.
Nitrogen rate: 0.5 to 1.0 pounds of actual nitrogen per 1,000 square feet depending on grass type (Bermuda at the high end; Centipede at the low end).
Summer (Second and Optional Third Application)
When: Six to eight weeks after the spring application, when the lawn shows the color and growth rate response fading from the previous application.
Bermuda: Can tolerate two additional summer applications. Total annual nitrogen for Bermuda should not exceed 5 to 6 pounds per 1,000 square feet.
Zoysia: One summer application is generally sufficient after the spring feeding.
St. Augustine: One to two summer applications. Avoid high-nitrogen applications in periods of intense heat (above 95 degrees Fahrenheit).
Centipede: Often only one application per year is needed (late spring). Do not apply in summer unless the lawn shows clear nitrogen deficiency. Centipede is prone to “Centipede decline” from excess nitrogen.
Fall. Do Not Fertilize
Do not apply fertilizer to warm-season grasses in fall. As these grasses approach dormancy, they cannot effectively use nitrogen, and late-season nitrogen delays dormancy entry, increases susceptibility to frost damage, and can weaken the lawn over winter.
If weeds are present in fall, address them with a targeted spot-spray herbicide rather than a weed and feed product that would also deliver nitrogen.
Fertilizer Schedule Summary Table
| Grass Type | Spring | Summer | Early Fall | Late Fall |
|---|---|---|---|---|
| Kentucky bluegrass | 0.75 lbs N | Skip or very light | 1.0 lbs N | 0.5 lbs N |
| Tall fescue | 0.5 lbs N | Skip | 1.0 lbs N | 0.5 lbs N |
| Fine fescue | 0.5 lbs N | Skip | 0.5 lbs N | Optional light |
| Perennial ryegrass | 0.75 lbs N | Skip or light | 1.0 lbs N | 0.5 lbs N |
| Bermuda grass | 1.0 lbs N (late spring) | 1.0 lbs N x2 | Do not apply | Do not apply |
| Zoysia | 0.75 lbs N (late spring) | 0.5 lbs N | Do not apply | Do not apply |
| St. Augustine | 0.75 lbs N (late spring) | 0.75 lbs N | Do not apply | Do not apply |
| Centipede | 0.5 lbs N (late spring) | Skip | Do not apply | Do not apply |
All nitrogen rates in pounds of actual nitrogen per 1,000 square feet.
Related Guides
For watering timing in relation to fertilizer application, see should you fertilize before or after rain. For a full explanation of how to calculate actual nitrogen per application from the NPK label, see lawn fertilizer basics.