SOD 101: The Turfgrass Library For Beginners, Lawn Geeks, and Pros

From lawn care basics to pro level sod, SOD101 helps you choose, grow, and maintain the right turf for your yard. Whether you’re trying to fix brown patches, choose the right grass for your climate, or just want to understand how sod really works, we’re here to help. At SOD101, we blend real world testing with clear guidance to support both beginners and seasoned pros.

  • Real World Test Results: Cobalt vs CitraBlue vs Palmetto vs Harmony Shade St Augustine in Texas

    When it comes to shade tolerant grasses in Texas, there is no shortage of options, but real world results are what matter.

    At SOD101, we tested four different St Augustine varieties side by side: Cobalt, CitraBlue, Palmetto, and a generic Harmony shade tolerant variety (available at Lowe’s and Home Depot).

    We all know that CitraBlue and Cobalt are relatively new to the St Augustine market, and that is exactly why they deserve a closer look. At SOD101, we have a passion for St Augustine turf, although we enjoy experimenting with other grasses as well. We are committed to testing newer strains in real soil, real conditions, and real weather to give homeowners and pros honest results that do not come from a brochure.

    What follows are our results, including heat, drought, growth, and appearance in a test area that receives about 6 hours of sun daily.

    Test Environment

    All four varieties were planted in partial shade on a Texas property. The soil is a typical sandy loam with a slightly acidic pH.

    A basic soil test revealed the following:

    • pH: 6.1
    • Nitrogen: Moderate
    • Potassium: High
    • Phosphorus: Low

    Each patch received equal mowing and maintenance, but irrigation was varied during peak heat to simulate drought stress.

    Drought Resistance Results

    Cobalt St Augustine showed the strongest drought performance.

    We withheld water for several days during peak summer. Cobalt held its color and density better than all other varieties, with little to no browning or thinning.

    CitraBlue held up well too, though it began to fade sooner than Cobalt.

    Palmetto and Harmony showed signs of stress first, with more browning and thinning under the same conditions.

    Top drought performer: Cobalt
    Close runner up: CitraBlue

    Spread and Growth Rate

    • Harmony was the fastest spreader. It covered ground quickly and filled in gaps aggressively.
    • Cobalt spread at a moderate pace, steady but not aggressive.
    • CitraBlue was the slowest to spread, showing minimal outward growth during the trial period.
    • Palmetto spread faster than CitraBlue but slower than Harmony or Cobalt.

    Fastest spreader: Harmony
    Most consistent: Cobalt
    Slowest: CitraBlue

    Side-by-side visual comparison of St Augustine grass varieties Cobalt, CitraBlue, Harmony, and Palmetto showing differences in stolon thickness and runner structure on a white background

    Blade and Stolon Comparison

    In terms of structure and density:

    • Cobalt had the largest stolons of any variety. Thick, prominent runners allowed it to hold its shape and fill in steadily over time.
    • CitraBlue featured the largest and densest blades. Its leaves were broader and more tightly packed than any other variety in this test, creating a lush and premium appearance.
    • Palmetto and Harmony had the traditional St Augustine look—with finer blades, thinner runners, and a lighter feel underfoot.

    As for color:

    • Cobalt had a bright light green tone that stood out in shade and sun.
    • CitraBlue had a deep dark green with bluish undertones, offering excellent curb appeal.
    • Palmetto and Harmony carried the classic St Augustine green most homeowners recognize.
    Side-by-side comparison of St Augustine grass blades showing CitraBlue with the widest, densest blades, followed by Cobalt, Palmetto, and Harmony shade variety
    Side-by-side stolon comparison of Cobalt, CitraBlue, Palmetto, and Harmony showing Cobalt with the thickest and most vigorous runners

    Thatch Development

    We also evaluated thatch buildup over the season:

    • Cobalt developed virtually no thatch.
    • CitraBlue had very light thatch, barely visible.
    • Palmetto and Harmony had a moderate amount of thatch that may require occasional dethatching or vertical mowing over time.

    Best for thatch control: Cobalt and CitraBlue

    Height and Mowing Frequency

    • Cobalt remained very low to the ground throughout the trial. It had a vertical growth habit but did not grow tall, resulting in very few mowing needs.
    • CitraBlue also maintained a low crawling growth habit, spreading slowly and staying compact.
    • Palmetto grew taller and faster, requiring moderate mowing and spreading at a fair pace.
    • Harmony was the tallest of the four. It required the most mowing and had the most aggressive horizontal spread.

    If low maintenance and mowing are a concern, Cobalt and CitraBlue lead the way.

    Spot Plugging Results in Established Lawns

    We also tested how well each grass performed when plugged into an existing St Augustine lawn.

    • Cobalt and CitraBlue were the slowest to establish in bare patches. They survived well but were slow to send out runners and fill gaps.
    • Palmetto and Harmony were much faster to fill in, especially Harmony, which sent out stolons quickly and closed gaps with ease.

    Cobalt and CitraBlue may be worth the patience, but for quicker results and visual recovery, a full sod makeover would be the better option when using these varieties.

    Final Takeaways for Texas Lawns

    Based on everything we observed, here are our takeaways:

    • Cobalt: Best overall performer. Top drought resistance, lowest thatch, stayed short, spread consistently, and had the strongest stolons. Its balanced growth habit and minimal maintenance needs make it ideal for many Texas lawns.
    • CitraBlue: Excellent blade density and deep color. Second best for drought and thatch, with a low-growing form that looks premium, but slow to spread.
    • Palmetto: Grows tall with moderate spread. Solid performer but edged out by the newer varieties in most categories.
    • Harmony Shade Variety: Fastest spreader and most aggressive grower. Taller, needs frequent mowing, and builds moderate thatch. Good for quick fixes or budget patches.

    We will continue monitoring performance throughout the seasons to track winter recovery, long term durability, and how each variety ages.

    Want More Real Grass Trials?

    Follow us here at SOD101 as we post ongoing updates, side by side comparisons, and personal insights from real testing—not marketing hype. Whether you are new to turfgrass or a pro who just wants results that make sense, we’re here to help you choose with confidence.