When to plant Onion in Collier County, FL
For Onion in Collier County, the safe spring window opens around December 22 and closes around January 12. Last expected frost is January 1, first fall frost December 31, giving a 365-day growing season. A second sowing from February 18 to March 4 extends the harvest into fall.
When to Plant Onion in Collier County, FL
Top priorities for Collier County, Florida gardeners in June
Here's what deserves your attention in Collier County, Florida this month. Everything below is tailored to Zone 10b and timed around your local frost dates.
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Collect onion at their peak
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
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.
Collier County, Florida is in USDA Zone 10b. The average last spring frost is January 12 and the first fall frost is April 15, giving you a growing season of approximately 93 days.
At an elevation of 185 feet, Collier County receives approximately 61.3 inches of rainfall annually with predominantly sand soil. Summer highs average 85°F, providing good warmth for Onion during the growing season. 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.
Collier County Soil Profile
Soil Type
Sand
Soil pH
5-6.2
Drainage
Well Drained
Soil Compatibility in Collier County
How your county's soil matches Onion's growing requirements.
Soil pH
Your soil pH (5.0–6.2) is more acidic than Onion prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Collier County warms quickly in spring but drains fast. Onion will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Onion.
Organic Matter
Organic matter is low (1.3%). Add 2-3 inches of compost before planting Onion.
How to Plant Onion
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Onion Water Budget
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" | 2.8" | 1.5" | 💧 Light watering |
| Feb | 4.3" | 3.3" | 1" | 💧 Light watering |
| Mar | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Apr | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| May | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jun | 4.3" | 7.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 10" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 9" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jan–Oct in Collier County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion 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.
Onion Planting Timeline — Collier County, FL
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 15 | Dec 15 – Dec 29 |
| Transplant Outdoors | January 12 | Jan 12 – Jan 26 |
| Direct Sow | December 22 | Dec 22 – Jan 12 |
| Harvest | April 13 | Apr 13 – Jun 1 |
| Fall Sowing | February 18 | Feb 18 – Mar 4 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Fall Sowing |
| March | Fall Sowing |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | Start Indoors Direct Sow |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 10b
📆 Growing Season
93 days in Collier County
Growing Tips for Onion in Collier County
Direct sow Onion outdoors after January 12 in Collier County when soil has warmed and frost danger has passed.
Sandy soil in Collier County dries quickly — mulch Onion with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
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 Collier County, FL?
Collier County is in Zone 10b with an average last frost of January 12. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Collier County, FL?
Collier County, Florida is in USDA Hardiness Zone 10b. The average last spring frost is January 12 and first fall frost is .
When should I plant Onion in Collier County, FL?
In Collier County, FL, plant Onion after the last frost (around January 1) and before the first frost (around December 31). Best results when soil holds above 50°F.
What growing zone is Collier County, FL for Onion?
Collier County sits in USDA Zone 10b. Onion grows reliably in zones 3a through 10b, so it's a good fit here.
Can Onion grow in Collier County's climate?
Yes — Onion grows well in Collier County's temperate climate. Collier County averages a 365-day frost-free season, with last frost around January 1 and first frost around December 31.
Your Collier County Garden Planner — Free
A 22-page printable planner built for Collier County (Zone 10b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.