When to Plant Sorrel in Humboldt County, CA
This month in Humboldt County, California
A quick April briefing for Humboldt County, California gardeners — what's urgent, what's next, and what can wait.
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Pick sorrel
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
A few tasks this April that'll pay off in May
- First harvests: sorrel
Sorrel is a perennial herb with tangy, lemon-flavored arrow-shaped leaves. It is one of the first greens to emerge in spring and is used in soups and salads.
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 Sorrel during the growing season. Sandy soil warms quickly in spring — great for early planting — but Sorrel 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
Plant 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 Sorrel's growing requirements.
Soil pH
Your soil pH (6.2–6.8) is within Sorrel's preferred range (5.5–7.0).
Soil Texture
Sandy soil in Humboldt County warms quickly in spring but drains fast. Sorrel 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 Sorrel.
How to Plant Sorrel
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Sorrel
Sow every 4.6 weeks. Last sowing by Sep 29 to harvest before frost.
For a dedicated fall crop, sow by Oct 03.
Plant Water Budget
Monthly Watering Guide for Sorrel
Sorrel needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sorrel Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.8" | 0" | ❄️ Dormant |
| Feb | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Mar | 4.3" | 3.3" | 1" | 💧 Light watering |
| Apr | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| May | 4.3" | 0.5" | 3.8" | 🚿 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" | 0.3" | 4" | 🚿 Regular watering |
| Oct | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Nov | 4.3" | 1.9" | 2.4" | 🚿 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.
Sorrel 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.
Sorrel Planting Timeline — Humboldt County, CA
Sorrel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 30 | Jan 30 – Feb 13 |
| Transplant Outdoors | February 20 | Feb 20 – Mar 6 |
| Direct Sow | February 6 | Feb 6 – Feb 27 |
| Harvest | April 3 | Apr 3 – Jun 5 |
| Fall Sowing | October 3 | Oct 3 – Oct 17 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
274 days in Humboldt County
Growing Tips for Sorrel in Humboldt County
Direct sow Sorrel outdoors after February 27 in Humboldt County when soil has warmed and frost danger has passed.
Sandy soil in Humboldt County dries quickly — mulch Sorrel with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Your generous 275.0-day season in Humboldt County allows multiple plantings of Sorrel. Sow every 20.0 days for continuous harvest.
Humboldt County receives only 22" of rain annually. Sorrel needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow in early spring or fall. Remove flower stalks promptly to encourage leaf production. Divide clumps every 3-4 years. Young leaves have the best flavor.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Sorrel in Other Locations
Frequently Asked Questions
When should I plant Sorrel in Humboldt County, CA?
Humboldt County is in Zone 9b with an average last frost of February 27. Plan your Sorrel 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.
Your Humboldt County Garden Planner — Free
A 24-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.