Lawn care calendar for California: when to fertilize and seed

Dates shift with the weather; follow the signs in the text.

Which grasses grow where in California

UC IPM divides lawn grasses in two. Cool-season grasses such as tall fescue, perennial ryegrass and Kentucky bluegrass do best in northern and coastal California, although they are grown throughout the state. Warm-season grasses such as bermudagrass, buffalograss, kikuyugrass, St. Augustinegrass and zoysiagrass grow best in southern California and the Central Valley, where summers are hot and dry and winters mild.

Warm-season grasses go dormant when soil temperature drops below 52 F and green up as it rises. Cool-season grasses need about 25% more water than warm-season grasses in the same place.

Frost dates from NOAA

Dates are the NOAA 1991-2020 normals for the last spring and first fall 32 F freeze at 50% probability. At Redding Municipal Airport the average last spring frost is March 3 and the average first fall frost is November 21. At Sacramento Metropolitan Airport the dates are February 22 and November 24, and at Fresno Yosemite International Airport January 14 and December 14.

San Francisco International lists December 29 for the last spring freeze and December 26 for the first fall freeze, a few days apart in the same week of winter, so there is no frost-free season to count there. NOAA publishes no 32 F date for Los Angeles International or San Diego International.

Spring

Begin a feeding program about 6 weeks after planting a new lawn, and use no more than 1 pound of actual nitrogen per 1,000 square feet in each application. Seeded bermudagrass takes 2 to 4 pounds of nitrogen a year, hybrids 4 to 6 pounds and tall fescue 3 to 6 pounds.

Weed prevention starts in spring. Use a preemergence herbicide before weeds emerge, and remember that overseeding may be impossible for weeks or months afterward. If you aerate, do it first, because the herbicide would be removed from the soil surface with the cores. Aerate in spring while the grass is actively growing, not in summer heat. Seeded bermudagrass is mowed at 1 to 1.5 inches, hybrids at 0.5 to 0.75 inch and tall fescue at 1.5 to 3 inches. Never go below 1.5 inches on fescue, and remove no more than a third of the blade at a time.

Summer

Water deeply and infrequently, enough to wet the soil 6 to 8 inches down, and water again when the top 2 inches have dried out. The best hours are between 2 and 8 in the morning. UC IPM warns that frequent light watering gives crabgrass a competitive edge and keeps roots shallow.

Several California counties limit watering to one day a week or to set days by address, so check your county before setting a timer. Warm-season grasses are in their active season and need frequent mowing, and tall fescue may slow in extreme heat.

Fall

Fall is the second planting season for cool-season grasses and the start of the second feeding window for tall fescue, which runs from September through December. Seed tall fescue at 8 to 10 pounds per 1,000 square feet.

Bermudagrass lawns get their last feeding in September and then go dormant. UC IPM advises that the last fertilizer application come 6 to 8 weeks before the likely first frost. Remove thatch that is more than a half inch thick. Traffic on dormant bermudagrass can damage it and let weeds in.

UC IPM and UC ANR

UC IPM, part of the University of California Agriculture and Natural Resources division, publishes the UC Guide to Healthy Lawns and a set of Pest Notes. For help with a specific lawn it points readers to their local Cooperative Extension office.