Controlling Moss and Algae from Lake Water Irrigation

Moss in Lawn Fed by Algae-Rich Lake Water

Moss thrives in damp, shady conditions. If your sprinkler system pulls algae-laden lake water, it may inoculate the lawn with algae and moss spores.

Treatment Options

• Fungicide/algicide: Spray affected areas with a labeled product.
• Baking soda spray: Dissolve 1–2 tbsp per gallon water; apply to moss. Safe for pets and beneficial insects.
• Vinegar or diluted bleach: Spot-treat on hardscapes (patio slabs), but avoid grass.
• Increase sunlight: Prune overhanging limbs to reduce shade.

Expert Help

Contact your county agricultural extension agent (listed under county government) for a site-specific diagnosis and treatment plan. They can test water and soil and recommend approved controls.

Addressing shade and moisture is key to long-term prevention.