When To Fertilize Bermuda Grass In Oklahoma

Getting your Bermuda grass lawn thick and green in Oklahoma starts with knowing when to fertilize. Timing your applications correctly is the single most important factor for success. This guide will walk you through the optimal schedule and methods to get the best results from your turf.

For optimal growth results, your fertilization schedule must follow the natural growth cycle of Bermuda grass. This warm-season grass wakes up in late spring, grows vigorously all summer, and goes dormant after the first hard frost. Feeding it at the wrong time can waste product, harm the grass, or help weeds.

Understanding Bermuda Grass Growth Cycles

Bermuda grass thrives in heat. Its root system starts absorbing nutrients once soil temperatures consistently reach about 55°F. Growth really takes off when soils hit 65–70°F. In Oklahoma, this typically happens from late April to mid-May, depending on if you’re in the cooler panhandle or the warmer southern regions.

The grass remains actively growing through the hot summer months. Growth slows as nights cool in late September, and the grass begins its transition into winter dormancy. Fertilizing outside this active window is ineffective and can be detrimental.

The Optimal Fertilization Schedule

Follow this general timeline for a healthy, resilient lawn. Always adjust based on your specific location and that year’s weather patterns.

1. Spring Green-Up (Late April to Early May)

This is your first and most critical application. Apply fertilizer as the grass exits dormancy and begins consistent green growth. Look for the lawn to be about 50% green. Using a quick-release nitrogen source here gives it a strong start.

What to use: A balanced fertilizer with a higher nitrogen (N) ratio, like a 20-5-10 or 15-5-10.
Key Tip: Do not fertilize too early! If a late frost hits after feeding, it can damage tender new growth.

2. Late Spring (Early to Mid-June)

About 4-6 weeks after your first feeding, give your lawn a second boost. This supports the rapid growth phase and helps it thicken up and outcompete summer weeds.

What to use: A fertilizer high in nitrogen. You can continue with a similar product to your spring application.

3. Peak Summer (Mid-July)

This application sustains the grass through the stress of peak Oklahoma heat. Ensure your lawn is receiving adequate water during this time to prevent burn.

What to use: A slow-release nitrogen formula is excellent here. It feeds the grass gradually over several weeks.

4. Late Summer / Early Fall (Late August to Early September)

This is your last nitrogen application for the year. It helps the grass recover from summer stress and build energy reserves in its roots for the winter ahead. It’s crucial to get this timing right.

What to use: Apply a balanced fertilizer or one with a slightly lower nitrogen content.
Critical Rule: Do not fertilize with nitrogen after September 15th in most of Oklahoma. Late feeding promotes tender growth that can be severely damaged by early frosts.

5. Late Fall (October to November)

After the grass has stopped growing but before the ground freezes, consider a “winterizer” application. This is not a nitrogen feed.

What to use: Apply a fertilizer high in potassium (K), the last number in the N-P-K ratio (e.g., 0-0-60 or a 10-0-20). Potassium strengthens cell walls and improves winter hardiness and drought resistance for the next year.

Choosing the Right Fertilizer

Reading the bag is essential. Look for the three-number N-P-K ratio, which stands for Nitrogen-Phosphorus-Potassium.

Nitrogen (N): Promotes lush, green blade growth. Bermuda grass lawns need regular nitrogen inputs.
Phosphorus (P): Supports root development. Most Oklahoma soils have adequate phosphorus, so a high middle number isn’t always necessary unless a soil test shows a deficiency.
Potassium (K): Aids in overall plant health, stress tolerance, and disease resistance. Important for summer heat and winter cold.

A soil test through the OSU Extension service is the best way to know exactly what your lawn needs. It can save you money and prevent over-application of certain nutrients.

Step-by-Step Application for Best Results

Mow First: Mow your lawn at your regular height before fertilizing. This removes debris and allows granules to reach the soil.
Check the Weather: Apply when rain is not expected for at least 24-48 hours, but while the grass is still moist. If rain isn’t forecast, water the lawn lightly a day before.
Calibrate Your Spreader: Whether using a broadcast or drop spreader, set it to the rate recommended on the fertilizer bag. This prevents striping and burning.
Apply Evenly: Walk at a steady pace, slightly overlapping your passes to ensure full coverage. Be careful not to overlap to much, which can cause over-application.
Water It In: Lightly water the lawn after application. This washes the fertilizer off the grass blades and into the soil, where roots can access it. About 1/4 inch of water is sufficient.

Common Mistakes to Avoid

Fertilizing Too Early in Spring: This feeds winter weeds, not your dormant grass.
Fertilizing Too Late in Fall: This is the most common error, leading to winter kill and disease.
Using Weed & Feed at the Wrong Time: Pre-emergent weed & feed products must be applied much earlier (March) to stop weed seeds. Using them in summer is ineffective for weeds and can stress the grass.
Overapplying: More is not better. It leads to excessive growth (more mowing), thatch buildup, pollution from runoff, and increased disease risk.
Ignoring Soil Health: Fertilizer feeds the plant, but healthy soil supports it. Core aeration in late spring can greatly improve results.

FAQ: Fertilizing Bermuda Grass in Oklahoma

When should I put out pre-emergent on my Bermuda lawn?

Timing for pre-emergent herbicides is separate from fertilization. Apply pre-emergent in early March to target spring weeds like crabgrass. A second application in early June can help with summer weeds.

Can I fertilize Bermuda grass in the winter?

No. Do not fertilize dormant, brown Bermuda grass with nitrogen. The only late-year application should be the potassium-only “winterizer” after growth has stopped.

How often should I fertilize Bermuda grass in summer?

Typically, two summer applications are plenty: one in early June and one in mid-July. Under high-maintenance programs (like for a golf course), it might be fed every 4-6 weeks, but this requires much more water and mowing.

What is the best fertilizer for Bermuda grass in Oklahoma?

There’s no single “best” product. A soil test will tell you what your lawn specifically needs. A general-purpose lawn fertilizer with a 3-1-2 or 4-1-2 ratio (like 15-5-10 or 20-5-10) is often a good, simple choice for the growing season.

Is it okay to fertilize a dry lawn?

No. Fertilizing a drought-stressed lawn can burn the grass. Water the lawn thoroughly a day or two before application if conditions are dry, and always water the fertilizer in after applying.

Should I bag my clippings after fertilizing?

It’s not necessary if you mow regularly. Leaving the clippings returns some nutrients to the soil. Just ensure you mow so that clippings are short and don’t clump, smothering the grass beneath.

By following this Oklahoma-specific schedule, you give your Bermuda grass exactly what it needs, exactly when it needs it. The result is a dense, green, and hardy lawn that can handle our state’s tough summers and winters. Remember, consistency is key—mark your calendar each year for these important feeding times to maintain your lawn’s optimal health.