Source: The Castaic, CA weather data displayed above is derived from the NOAA (National Oceanic and Atmospheric). Air quality and pollution data is derived from the EPA (United States Environmental Protection Agency). Air quality and pollution levels measured in a particular area may not be representative of the entire county.
Plant fescues when fall temperature reach about 75 F. The next best time to plant fescue seeds is when rising temperatures in spring reach 60 F. Summer isn't a good time to plant fescue lawns, because fescue grass tends to go dormant during periods of high temperature.
Now is the Time to Seed Tall Fescue By Mary Helen Ferguson, Extension Agent, Horticulture While we can grow other turfgrasses in this area (e.g., bermudagrass, zoysiagrass, etc.), tall fescue is probably the most popular one. Now, during the first half of September, is the best time to seed tall fescue in our part of the state. It is also a good time to seed blends of tall fescue with Kentucky bluegrass. (NC State turfgrass specialists do not recommend planting Kentucky bluegrass by itself in the Piedmont, since it is not heat tolerant enough. However, when planted with tall fescue, it can help fill in thin spots, since it spreads by rhizomes, or underground stems, whereas tall fescue does not.)