When to plant Corn in San Mateo County, CA
For San Mateo County, gardeners: plant Corn January 25 through February 15 once soil reads 50°F.
When to Plant Corn in San Mateo County, CA
Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.
San Mateo County, California is in USDA Zone 10a. The average last spring frost is January 18 and the first fall frost is December 12, giving you a growing season of approximately 328 days.
At an elevation of 277 feet, San Mateo County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Corn to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Corn successfully. Mulch heavily to conserve soil moisture.
San Mateo County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
Drainage
Well Drained
How Much Corn to Grow
For a family of 4, plant approximately 60 corn plants in about 120 sq ft. In San Mateo County's 328-day season, you'll have plenty of time for a full harvest. Plan your garden layout →
Monthly Watering Guide for Corn
Corn needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Corn Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Feb | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Mar | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Apr | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Oct | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Nov | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Dec | 4.3" | 2.9" | 1.4" | 💧 Light watering |
Water needs are for active growing months only (Jan–Dec in San Mateo County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Corn Planting Timeline — San Mateo County, CA
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | January 25 | Jan 25 – Feb 15 |
| Harvest | March 29 | Mar 29 – May 24 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Direct Sow |
| February | Direct Sow |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–100 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 10a
📆 Growing Season
328 days in San Mateo County
Growing Tips for San Mateo County
Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Corn in Other Locations
Frequently Asked Questions
When should I plant Corn in San Mateo County, CA?
San Mateo County is in Zone 10a with an average last frost of January 18. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Mateo County, CA?
San Mateo County, California is in USDA Hardiness Zone 10a. The average last spring frost is January 18 and first fall frost is December 12.
When should I plant Corn in San Mateo County, CA?
In San Mateo County, CA, plant Corn after the last frost (around January 18) and before the first frost (around December 12). Best results when soil holds above 50°F.
What growing zone is San Mateo County, CA for Corn?
San Mateo County sits in USDA Zone 10a. Corn grows reliably in zones 3a through 11b, so it's a good fit here.
Can Corn grow in San Mateo County's climate?
Yes — Corn grows well in San Mateo County's temperate climate. San Mateo County averages a 329-day frost-free season, with last frost around January 18 and first frost around December 12.
Your San Mateo County Garden Planner — Free
A 22-page printable planner built for San Mateo County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.