When to plant Corn in Humboldt County, CA
For Corn in Humboldt County, the safe spring window opens around March 6 and closes around March 27. Last expected frost is February 27, first fall frost November 28, giving a 275-day growing season.
When to Plant Corn in Humboldt County, CA
What to do in June
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Humboldt County, California.
-
Collect corn at their peak
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Looking ahead to July
- First harvests: corn
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.
Humboldt County, California is in USDA Zone 9b. The average last spring frost is February 27 and the first fall frost is November 28, giving you a growing season of approximately 274 days.
At an elevation of 148 feet, Humboldt County receives approximately 22.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Corn during the growing season. Sandy soil warms quickly in spring — great for early planting — but Corn will need more frequent watering and organic matter to retain nutrients.
Humboldt County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.2-6.8
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 Humboldt County
How your county's soil matches Corn's growing requirements.
Soil pH
Your soil pH (6.2–6.8) is within Corn's preferred range (6.0–7.0).
Soil Texture
Sandy soil in Humboldt 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 20 to harvest before frost.
Corn Water Budget
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 | — | 4.8" | 0" | ❄️ Dormant |
| Feb | 6.5" | 5" | 1.5" | 💧 Light watering |
| Mar | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Apr | 6.5" | 1.7" | 4.8" | 🚿 Regular watering |
| May | 6.5" | 0.5" | 6" | 🚿 Regular watering |
| Jun | 6.5" | 0.1" | 6.4" | 🚿 Regular watering |
| Jul | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Aug | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Sep | 6.5" | 0.3" | 6.2" | 🚿 Regular watering |
| Oct | 6.5" | 0.8" | 5.7" | 🚿 Regular watering |
| Nov | 6.5" | 1.9" | 4.6" | 🚿 Regular watering |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Humboldt 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 — Humboldt County, CA
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 6 | Mar 6 – Mar 27 |
| Harvest | May 8 | May 8 – Jul 3 |
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
274 days in Humboldt County
Growing Tips for Corn in Humboldt County
Direct sow Corn outdoors after February 27 in Humboldt County when soil has warmed and frost danger has passed.
Sandy soil in Humboldt 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.
Humboldt County receives only 22" of rain annually. Corn needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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
Frequently Asked Questions
When should I plant Corn in Humboldt County, CA?
Humboldt County is in Zone 9b with an average last frost of February 27. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Humboldt County, CA?
Humboldt County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 27 and first fall frost is November 28.
When should I plant Corn in Humboldt County, CA?
In Humboldt County, CA, plant Corn after the last frost (around February 27) and before the first frost (around November 28). Best results when soil holds above 50°F.
What growing zone is Humboldt County, CA for Corn?
Humboldt County sits in USDA Zone 9b. Corn grows reliably in zones 3a through 11b, so it's a good fit here.
Can Corn grow in Humboldt County's climate?
Yes — Corn grows well in Humboldt County's temperate climate. Humboldt County averages a 275-day frost-free season, with last frost around February 27 and first frost around November 28.
Your Humboldt County Garden Planner — Free
A 22-page printable planner built for Humboldt 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.