When to plant Onion in Pinellas County, FL
For Onion in Pinellas County, the safe spring window opens around January 4 and closes around January 25. Last expected frost is January 25, first fall frost December 16, giving a 326-day growing season. A second sowing from October 21 to November 4 extends the harvest into fall.
When to Plant Onion in Pinellas County, FL
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.
Pinellas County, Florida is in USDA Zone 10a. The average last spring frost is January 25 and the first fall frost is December 16, giving you a growing season of approximately 325 days.
At an elevation of 246 feet, Pinellas County receives approximately 58.1 inches of rainfall annually with predominantly sand soil. Summer highs average 102°F, so Onion may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Onion will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.
Pinellas County Soil Profile
Soil Type
Sand
Soil pH
5.1-6.2
Drainage
Well Drained
Monthly Watering Guide for Onion
Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Onion Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Feb | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Mar | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Apr | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 7.6" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 8.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.7" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 7.1" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Dec | 4.3" | 2.6" | 1.7" | 💧 Light watering |
Water needs are for active growing months only (Jan–Dec in Pinellas County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion Planting Timeline — Pinellas County, FL
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 28 | Dec 28 – Jan 11 |
| Transplant Outdoors | January 25 | Jan 25 – Feb 8 |
| Direct Sow | January 4 | Jan 4 – Jan 25 |
| Harvest | April 26 | Apr 26 – Jun 14 |
| Fall Sowing | October 21 | Oct 21 – Nov 4 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Transplant Outdoors Direct Sow |
| February | Transplant Outdoors |
| March | — |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | Fall Sowing |
| December | Start Indoors |
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 10a
📆 Growing Season
325 days in Pinellas County
Growing Tips for Pinellas 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
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Check more plant combinations with our Companion Planting Checker →
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Pinellas County, FL?
Pinellas County is in Zone 10a with an average last frost of January 25. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pinellas County, FL?
Pinellas County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is January 25 and first fall frost is December 16.
When should I plant Onion in Pinellas County, FL?
In Pinellas County, FL, plant Onion after the last frost (around January 25) and before the first frost (around December 16). Best results when soil holds above 50°F.
What growing zone is Pinellas County, FL for Onion?
Pinellas County sits in USDA Zone 10a. Onion grows reliably in zones 3a through 10b, so it's a good fit here.
Can Onion grow in Pinellas County's climate?
Yes — Onion grows well in Pinellas County's temperate climate. Pinellas County averages a 326-day frost-free season, with last frost around January 25 and first frost around December 16.
Your Pinellas County Garden Planner — Free
A 22-page printable planner built for Pinellas 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.