← Back to Garden Insights

How-To Guide

How to Fix Common Lawn Problems in San Diego (Brown Patches, Weeds, Thatch)

Brown patches in San Diego lawns are often watering, thatch, or compaction — not a mystery fungus. Diagnose before you spray.

San Diego lawn with brown patches

Look Past the Color

UC IPM urges checking irrigation, mowing, fertilizer, drainage, insects, and thatch before assuming disease. Warm-season grasses common here (bermuda, kikuyu, St. Augustine) have their own patterns.

San Diego lawn with brown patches

Materials Required

  • Soil probe
  • Mower with sharp blade
  • Dethatching rake or verticut rental if thatch >1/2 in
  • Irrigation flags for broken heads

Step by Step

  1. Rule out abiotic causes

    Check dog urine spots, fuel spills, dull-mower scalp, and broken sprinklers. Sudden widespread damage is often cultural, not one pathogen.

  2. Measure thatch

    Up to about 1/2 inch can help; thicker thatch holds moisture against crowns and favors disease. Verticut heavy thatch producers like bermuda and kikuyu.

  3. Water deeply, early

    Irrigate pre-dawn or early morning to shorten leaf wetness. Water to several inches depth when needed — not nightly light sprays.

  4. Watch Rhizoctonia patterns

    Large/brown patch on warm-season turf is favored by poor drainage, thick thatch, long wet leaves, low mow height, and excess nitrogen.

  5. Decide: repair or replace

    Chronic problem lawns in unused areas may be better as mulched beds or groundcovers that match your water goals.

San Diego Tips

  • Inspect weekly in transition seasons.
  • Avoid lush, soft growth from heavy nitrogen before cool wet weather.

Want help getting this done right? Gardens of Gold designs and installs water-smart landscapes across San Diego County. Get a quote.