When To Fertilize Centipede Grass

Knowing when to fertilize centipede grass is the single most important factor for keeping it healthy and green. If you get the timing wrong, you can actually harm your lawn instead of helping it. This guide will walk you through the optimal growth timing, step by step, so you can have a beautiful, low-maintenance yard.

Centipede grass is unique. It’s known for being low-fuss, but that means it has specific needs, especially with fertilizer. Too much or the wrong kind can cause iron chlorosis (yellowing), thatch buildup, and make it vulnerable to cold. The goal is to support its natural growth cycle, not force it.

This is the golden rule for centipede grass: fertilize only once or twice a year, and always after it has fully greened up in the spring. The most critical application is in late spring to early summer. A second, lighter feeding might be done in mid-summer if the lawn shows it needs it, but often, one feeding is plenty.

The Ideal Fertilization Window

The best time to apply fertilizer is when the soil is consistently warm, and the grass is actively growing. For most of its growing range (USDA zones 7-9), this window is typically between late April and early June. Watch your lawn, not just the calendar.

Soil Temperature is Key: Wait until soil temperatures at a 4-inch depth reach about 70°F. You can find local soil temp data online or use a simple soil thermometer.
Visual Cue: Your centipede grass should be completely out of winter dormancy and fully green. If it’s still patchy or pale, wait.
Never Fertilize in Fall: This is a common mistake. Fall feeding promotes tender new growth that can be killed by the first frost, damaging the whole lawn.

Why Timing Matters So Much

Centipede grass has a slow growth habit and relatively low nitrogen needs. Fertilizing too early in spring shocks the grass before its roots are active. Fertilizing too late risks winter injury. The right timing ensures the nutrients are used for steady, strong growth and root development, not just a quick, weak burst of green.

Choosing the Right Fertilizer

Not just any lawn fertilizer will do. You need a product that matches centipede grass’s specific preferences.

Nutrient Ratio: Look for a complete lawn fertilizer with a ratio like 15-0-15 or 16-4-8. The key is that the first number (Nitrogen) and last number (Potassium) are balanced or nearly so.
Includes Iron: A fertilizer that includes iron (often listed as “with iron” or “Fe”) is excellent for centipede grass. It promotes greening without the excessive growth that high nitrogen causes.
Slow-Release Nitrogen: This is highly recommended. It feeds the grass gradually over 6-8 weeks, preventing burn and providing consistent nutrition.
What to Avoid: Stay away from “weed and feed” products unless you have a confirmed, significant weed problem. They often contain herbicides that can stress centipede grass.

A Note on Soil Testing

Before you fertilize, consider a soil test. It’s the only way to know exactly what your soil lacks. Your local cooperative extension office offers cheap kits. The results will tell you your soil’s pH (centipede likes 5.0 to 6.0) and precise nutrient levels, so you don’t guess.

Step-by-Step Fertilization Process

Mow First: Mow your lawn to its normal height (about 1.5 to 2 inches) a day or two before applying fertilizer. This ensures the granules reach the soil.
Check the Spreader: Use a broadcast (rotary) or drop spreader. Calibrate it according to the fertilizer bag’s settings to avoid over-application. This step is crucial.
Apply Evenly: Walk at a steady pace, slightly overlapping your passes to prevent striping. If possible, apply half the product walking north-south and the other half walking east-west for super even coverage.
Water It In: Lightly water the lawn after application. This washes the fertilizer off the grass blades and into the soil, preventing burn and starting the feeding process. Don’t flood it; a quarter-inch of water is fine.

What to Do After You Fertilize

Your job isn’t quite done after the spreader is put away. Proper post-application care ensures the fertilizer works correctly and your lawn stays healthy.

Resume Regular Watering: Centipede grass is drought-tolerant but needs about 1 inch of water per week from rainfall or irrigation, especially after feeding.
Mow Regularly: Keep mowing at the recommended height. Never cut more than one-third of the grass blade at once. This prevents stress.
Observe: Watch for a gradual improvement in color and density over the next 3-5 weeks. If you see yellowing, it might indicate an iron deficiency, which can be adressed with a separate iron supplement.

Common Mistakes to Avoid

Even with good intentions, its easy to make errors. Here are the big ones to steer clear of.

Over-fertilizing: This is the #1 mistake. It leads to thatch, pest problems, and a weak root system. More is not better.
Using High-Nitrogen Fertilizers: Products with a very high first number (like 30-0-0) cause rapid, weak growth that centipede grass cannot sustain.
Fertilizing at Dormancy: Applying fertilizer when the grass is brown (in winter or early spring) is a total waste and can pollute waterways.
Ignoring Soil pH: If your soil pH is too high (alkaline), centipede grass can’t absorb nutrients, even if they’re present. A soil test will reveal this.

Seasonal Care Calendar for Centipede Grass

Fertilization is just one part of the yearly cycle. Here’s a quick overview of what to do and when.

Late Spring (May-Jun): Primary fertilization time. Apply fertilizer and iron if needed. This is also a good time for pre-emergent herbicide if you have crabgrass issues.
Summer (Jul-Aug): Monitor for drought stress. Water deeply but infrequently. Only apply a second, very light fertilizer feeding if the lawn appears pale and a soil test suggests a need.
Early Fall (Sep-Oct): No fertilizer. This is the time for core aeration if thatch is over ½ inch thick. You can also overseed bare spots if necessary.
Late Fall/Winter (Nov-Feb): The lawn is dormant. Keep leaves raked off to prevent smothering. This is the ideal time to get your soil test done.

FAQ: Your Centipede Grass Questions Answered

Can I fertilize centipede grass in the fall?

No, you should not fertilize centipede grass in the fall. It stimulates new growth that will be damaged by frost, weakening the plant before winter. The last feeding should be done by mid-summer at the absolute latest.

What is the best month to fertilize centipede?

The best month varies by climate, but it’s typically May or early June. Wait until the grass is fully green and actively growing after winter dormancy.

How often should you really fertilize centipede grass?

For most lawns, once per year is sufficient. Some may benefit from a second light feeding in summer, but this is not a requirement. Over-fertilization is a far more common problem than under-fertilization with this grass type.

Why is my centipede grass yellow after fertilizing?

Yellowing after fertilizing can be caused by a few things. The most likely is iron deficiency, which is common in centipede grass, especially if the soil pH is high. An application of iron sulfate or chelated iron can correct this. It could also be fertilizer burn from uneven application or not watering it in properly.

Is milorganite good for centipede grass?

Milorganite is an organic, slow-release fertilizer that can be a good option. It’s low in nitrogen and contains iron, which fits centipede’s needs well. However, because it’s low-nutrient, you may need to apply a bit more volume compared to a synthetic fertilizer to meet the lawn’s needs.

Getting the timing right for when to fertilize centipede grass simplifies your lawn care immensely. By feeding it just once, at the right moment with the right product, you work with its natural habits. This approach saves you time, money, and effort while giving you a thick, green lawn that’s resilient against heat, drought, and wear. Remember, the key to a great centipede lawn is often less, not more. Pay attention to its cues, and you’ll be rewarded with a beautiful yard that doesn’t demand constant work.