When does pre-emergent application typically open in San Jose, CA?

Pre-emergent application typically opens in April to May for San Jose, CA, when 2-inch soil temperature reaches the 50–55°F threshold for several consecutive days. Apply earlier than that and the herbicide degrades before crabgrass germinates; apply later and weeds have already sprouted. This is informational guidance only, not a prescription. The label is the law. Consult your local Cooperative Extension office before applying any product.

What grass types grow best in San Jose, CA?

San Jose, CA is a transition zone where both cool-season and warm-season grasses are common. Cool-season grasses (tall fescue, Kentucky bluegrass, perennial ryegrass, fine fescue) thrive when 2-inch soil sits in the 50–65°F range and slow down in midsummer heat. Picking a grass family that matches the climate is the single biggest lawn-care decision; transition-zone homeowners often maintain blends and accept that neither family will look perfect year-round. This is informational guidance only, not a prescription. The label is the law. Consult your local Cooperative Extension office before applying any product.

When is the first fall frost typically expected in San Jose, CA?

In San Jose, CA, the first fall frost typically arrives around December 25. Soil temperature continues to drop through October and November, which closes the fall fertilizer window for warm-season grasses and opens the dormant-seeding window for cool-season grasses. This is informational guidance only, not a prescription. The label is the law. Consult your local Cooperative Extension office before applying any product.

How often is this schedule updated?

Recommendations recompute every 6 hours from the latest reading at Merced 23 WSW, about 56 miles from San Jose. This is informational guidance only, not a prescription. The label is the law. Consult your local Cooperative Extension office before applying any product.

What soil temperature do cool-season grasses need to germinate?

Cool-season grasses like fescue, Kentucky bluegrass, and perennial ryegrass germinate best when 2-inch soil temperature sits in the 50–65°F range for several consecutive days. Above that, summer heat stresses young seedlings; below that, germination slows or stalls. The re-entry interval (REI) on any post-emergent products you apply during establishment is on the product label; respect it before letting pets or children back on treated areas. This is informational guidance only, not a prescription. The label is the law. Consult your local Cooperative Extension office before applying any product.

Where does the soil temperature data for San Jose come from?

Soil temperature for San Jose comes from Merced 23 WSW, a station in the NOAA US Climate Reference Network (USCRN) located about 56 miles away. Daily readings at depths from 2 inches down to 40 inches feed the schedule's window-open and window-closing decisions. This is informational guidance only, not a prescription. The label is the law. Consult your local Cooperative Extension office before applying any product.

Home Locations Guides

Tools

Live Soil Temperature Map Soil Moisture MapLawn-Care Schedule4-Inch Soil Temperature Soil Temperature by Depth Growing Degree Days

Home Locations Guides Tools

Live Soil Temperature Map Soil Moisture MapLawn-Care Schedule4-Inch Soil Temperature Soil Temperature by Depth Growing Degree Days

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California
San Jose, CA
Lawn Care Schedule

Lawn Care Schedule for San Jose, CA

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Right now in San Jose

79°F at 2-inch depth · Measured in the ground · Merced 23 WSW (NOAA USCRN #93243), 56 mi E · read 2 days ago (Sep 10, 2026) · updates nightly with about a 1-day sensor lag

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Data provided by USDA NRCS SCAN Network and NOAA USCRN. Modeled fallback: modeled estimates when a current station reading is unavailable. Updated daily. For official agricultural data, visit nrcs.usda.gov (opens in new tab).

Tools Live Soil Temperature Map Soil Moisture MapLawn-Care Schedule4-Inch Soil Temperature Soil Temperature by Depth Growing Degree Days Locations Stations Guides Methodology About

Home
California
San Jose, CA
Lawn Care Schedule

Lawn Care Schedule for San Jose, CA

See another city's schedule →

Right now in San Jose

79°F at 2-inch depth · Measured in the ground · Merced 23 WSW (NOAA USCRN #93243), 56 mi E · read 2 days ago (Sep 10, 2026) · updates nightly with about a 1-day sensor lag

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Check your local rules

Marin and Sonoma counties restrict pesticide application on public and some private parcels beyond state law. Source
California drought-emergency declarations trigger watering-day restrictions enforced by local water suppliers; check your provider for current stage. Source
California requires independent product registration via the Department of Pesticide Regulation; some EPA-registered products are not legal for sale or use in CA. Source

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About this schedule

Soil at 2 inches is currently 79°F. That is 4°F above the 30-year normal for this date. Data from NOAA US Climate Reference Network (USCRN), 56 miles away at Merced 23 WSW. First fall frost typically arrives around December 25.

More for San Jose, CA

Soil temperature for this area

Soil temperature in San Jose, CA

Nearby schedules

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Related guides

Affordable lawn renovation: a new homeowner's guide
When to apply pre-emergent herbicide
Fall pre-emergent timing for poa annua
Winterizer timing: when to stop fertilizing
When to apply broadleaf weed killer (cool-season lawns)
When to apply broadleaf weed killer (warm-season lawns)
Spring overseeding for cool-season grass
Spring lawn fertilization timing

Sources

Penn State Extension: Managing Thatch in Lawns (2025)
NC State Extension: Carolina Lawns: A Guide to Maintaining Quality Turf in the Landscape (2021)
University of Maryland Extension: Maintaining an Established Lawn (2026)
Penn State Extension: Liming Turfgrass Areas (2002)
Virginia Cooperative Extension (Virginia Tech): Fall Lawn Care (2025)
Penn State Extension: Lawn Establishment (2025)
University of Maryland Extension: Starting a New Lawn (2026)
Penn State Extension: Control of Summer Annual Grass Weeds in Turfgrasses (2024)
University of Maryland Extension: Crabgrass (2023)
University of Minnesota Extension: Fertilizing Lawns (2024)
Penn State Extension: Turfgrass Fertilization: A Basic Guide for Professional Turfgrass Managers (2016)
Purdue Extension: Control of Broadleaf Weeds in Homelawns (AY-9-W) (2019)
University of Minnesota Extension: Lawn Weeds (2023)
University of Georgia Extension: Turfgrass Fertility: Understanding Fertilizer Labels, Macronutrients, and Micronutrients (2016)
Penn State Extension: The Impact of Mowing on Weed Pressure (2025)
University of Minnesota Extension: Mowing Practices for Healthy Lawns (2024)
University of Illinois Extension: Managing Lawns During Drought (2023)
Virginia Cooperative Extension: Summer Lawn Management: Watering the Lawn (2024)
Penn State Extension: White Grubs in Home Lawns (2024)
Purdue Extension Entomology: Managing White Grubs in Turfgrass (2023)
NC State Extension TurfFiles: Annual Bluegrass (2022)
University of Georgia Extension: Annual Bluegrass Control in Residential Turfgrass (2024)
Iowa State University Extension: Core Aeration of Lawns (September and April; no temperature given) (2024)
Michigan State University Extension: Improving soil conditions for turf with fall aeration (late summer to early fall; no temperature given) (2023)
Penn State Extension: Soil Testing (2026)
University of Maryland Extension: Soil Testing and Soil Testing Labs (2026)

Latest soil reading: Sep 10, 2026 (2 days ago).

Schedule last updated: 14:27 UTC-8