When to plant Onion in Modoc County, CA
Modoc County's spring Onion window runs May 17 through June 7. time plantings around the expected last-frost window for best survival. A second sowing from July 13 to July 27 extends the harvest into fall.
When to Plant Onion in Modoc County, CA
Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.
Modoc County, California is in USDA Zone 6b. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.
At an elevation of 2,205 feet, Modoc County receives approximately 28.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Onion to ensure they mature before fall.
Modoc County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Onion Planting Timeline — Modoc County, CA
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 26 | Apr 26 – May 10 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Harvest | August 30 | Aug 30 – Oct 18 |
| Fall Sowing | July 13 | Jul 13 – Jul 27 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
113 days in Modoc County
Growing Tips for Modoc County
Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Modoc County, CA?
Modoc County is in Zone 6b with an average last frost of May 31. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Modoc County, CA?
Modoc County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 31 and first fall frost is September 21.
When should I plant Onion in Modoc County, CA?
In Modoc County, CA, plant Onion after the last frost (around May 31) and before the first frost (around September 21). Best results when soil holds above 50°F.
What growing zone is Modoc County, CA for Onion?
Modoc County sits in USDA Zone 6b. Onion grows reliably in zones 3a through 10b, so it's a good fit here.
Can Onion grow in Modoc County's climate?
Yes — Onion grows well in Modoc County's temperate climate. Modoc County averages a 113-day frost-free season, with last frost around May 31 and first frost around September 21.
Your Modoc County Garden Planner — Free
A 22-page printable planner built for Modoc County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.