When to plant Corn in Marshall, CA
For Corn in Marshall, the safe spring window opens around March 5 and closes around March 26. Last expected frost is February 26, first fall frost November 26, giving a 274-day growing season.
When to Plant Corn in Marshall, CA
This month in Marin County, California
A quick July briefing for Marin County, California gardeners — what's urgent, what's next, and what can wait.
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It's harvest week for corn
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
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.
Marshall, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.
At an elevation of 302 feet, Marin County receives approximately 36 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 81°F, so choose short-season varieties of Corn to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Corn will need more frequent watering and organic matter to retain nutrients.
Marshall Soil Profile
Soil Type
Sandy Loam
Soil pH
6-6.9
Drainage
Well Drained
Corn Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Marshall
How your county's soil matches Corn's growing requirements.
Soil pH
Your soil pH (6.0–6.9) is within Corn's preferred range (6.0–7.0).
Soil Texture
Sandy soil in Marin County warms quickly in spring but drains fast. Corn will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Corn.
How to Plant Corn
Succession Planting Corn
Sow every 6.9 weeks. Last sowing by Aug 18 to harvest before frost.
Corn Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Corn
Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Corn Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 7.2" | 0" | ❄️ Dormant |
| Feb | 6.5" | 6.5" | 0" | ✅ Rainfall sufficient |
| Mar | 6.5" | 6.2" | 0.3" | 💧 Light watering |
| Apr | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| May | 6.5" | 1" | 5.5" | 🚿 Regular watering |
| Jun | 6.5" | 0.2" | 6.3" | 🚿 Regular watering |
| Jul | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Aug | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Sep | 6.5" | 0.4" | 6.1" | 🚿 Regular watering |
| Oct | 6.5" | 1.4" | 5.1" | 🚿 Regular watering |
| Nov | 6.5" | 3.5" | 3" | 💧 Light watering |
| Dec | — | 6.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Marin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Corn Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Corn Planting Timeline — Marshall, CA
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 5 | Mar 5 – Mar 26 |
| Harvest | May 7 | May 7 – Jul 2 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
60–100 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
273 days in Marin County
Growing Tips for Corn in Marshall
Direct sow Corn outdoors after February 26 in Marin County when soil has warmed and frost danger has passed.
Sandy soil in Marin County dries quickly — mulch Corn with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Common pests for Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.
General growing tips
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
When should I plant Corn in Marshall, CA?
In Marshall, CA, plant Corn after the last frost (around February 26) and before the first frost (around November 26). Best results when soil holds above 50°F.
What growing zone is Marshall, CA for Corn?
Marshall sits in USDA Zone 9b. Corn grows reliably in zones 3a through 11b, so it's a good fit here.
Can Corn grow in Marshall's climate?
Yes — Corn grows well in Marshall's temperate climate. Marshall averages a 274-day frost-free season, with last frost around February 26 and first frost around November 26.
Your Marin County Garden Planner — Free
A 22-page printable planner built for Marin County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.