Using Sugar as an Organic Lawn Treatment for St. Augustine Grass

Introduction

Many homeowners struggle with weeds, pests, and invasive grasses like Bermuda in their St. Augustine lawns. An organic approach using ordinary white sugar can transform soil health, suppress weeds, and encourage beneficial wildlife—all without synthetic chemicals.

How Sugar Works

Sugar doesn't kill weeds or insects directly. Instead, it feeds beneficial soil microbes that work continuously to enrich the soil. Weeds thrive in poor soil; as the soil becomes richer, weeds weaken and disappear. A healthy, microbe-rich soil also supports toads, lizards, and grass snakes that consume harmful insects such as chinch bugs, grubs, and sod webworms.

Application Guidelines

• Rate: 1 pound of sugar per 250 square feet of lawn and garden.
• Timing: Apply in spring and fall; in extreme heat, a summer application can help stressed microbes.
• Method: Broadcast by hand or spreader, then water deeply (at least 6 inches) to dissolve the sugar and activate microbes.
• Critical Rule: Do not use chemical fertilizers, herbicides, or pesticides—they kill the microbes sugar supports.

Addressing Common Issues

Weeds (Crabgrass, Broadleaf, Bermuda Grass)

Existing weeds begin dying within a few mowings after the first sugar application. Over 2–3 years, weed pressure drops dramatically. Bermuda grass is crowded out by vigorous St. Augustine in rich soil. For persistent Bermuda, plug St. Augustine and maintain organic practices.

Pests (Ants, Chinch Bugs, Grubs, Webworms)

Sugar watered in well does not attract ants. Beneficial predators (toads, lizards, snakes) naturally control pests. Create toad houses and avoid chemicals that drive these allies away.

Fungal Diseases

Baking soda (1/4 cup per gallon of water) sprayed on affected areas works better than chemical fungicides for brown patch and dollar spot. Corn gluten also suppresses fungus while adding nutrients.

Additional Organic Practices

• Deep, infrequent watering (once weekly to 6-inch depth) encourages deep roots and prevents thatch.
• Mow high (3+ inches) and leave clippings to recycle nutrients.
• Use cedar bark mulch around foundations to deter termites and fleas.
• Plant lavender and rosemary to repel household insects.

Conclusion

Switching to a total organic program—sugar, deep watering, proper mowing, and zero chemicals—creates a self-sustaining lawn that stays thick, green, and weed-free with minimal effort. For deeper knowledge, explore Howard Garrett's resources at dirtdoctor.com.