The Science Behind Using Sugar as a Soil Amendment for Weed Control

Origin

Horticulturist Howard Garrett (Dirt Doctor) recommended dry molasses; table sugar is a close substitute. The author tried it 8 years ago—weeds vanished.

Personal Results

• 8 years of only sugar on lawn → thick, green, weed-free.
• Asthma improved 90%.
• Roses: baking soda spray (spring/rainy) controls black spot; lizards eat aphids.
• Indoor herbs repel cockroaches, ants, silverfish.

Why It Works (Theory)

Sugar = carbon energy for soil bacteria. Bacteria explode, digest organic matter, release nutrients, improve soil structure. Healthy soil = healthy plants = fewer pests/diseases. No peer-reviewed papers, but results speak.

Dry Molasses vs. Sugar

Dry molasses has minerals but is heavier (40-lb bags). Sugar is cheaper, easier, and worked better for this gardener.

Try it. You'll like it.