Seeding Into Existing St. Augustine Lawn in Los Angeles

An LA homeowner wants to overseed 400 sq ft into existing St. Augustine, using Milorganite and cool-season seed for winter color.

Critical First Steps

1. Identify the St. Augustine variety — hybrids (Floratam, Seville, Raleigh, Palmetto) are vegetatively propagated and don't come true from seed. Seeded types are inferior. Visit your UC Cooperative Extension office for identification.
2. Soil test before fertilizing — Milorganite (6-2-0) may not address your actual deficiencies. A lab test reveals precise needs.

Overseeding Reality

Cool-season grasses (rye, fescue) can provide winter green but compete with St. Augustine in spring transition. They'll die out as temperatures rise, potentially stressing the warm-season turf. Matching St. Augustine varieties requires plugs or sod, not seed.

Recommended Path

Get the variety ID and soil test first. Then decide: plug gaps with matching variety, or accept temporary winter rye with managed spring transition.