When to Plant Onion in Morris County, NJ
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.
Morris County, New Jersey is in USDA Zone 6b. The average last spring frost is March 29 and the first fall frost is November 12, giving you a growing season of approximately 228 days.
At an elevation of 227 feet, Morris County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Onion during the growing season.
Morris County Soil Profile
Soil Type
Silt Loam
Soil pH
5.1-6.5
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 | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Apr | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| May | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | 4.3" | 3" | 1.3" | 💧 Light watering |
| Dec | — | 2.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Morris County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion Planting Timeline — Morris County, NJ
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 22 | Feb 22 – Mar 8 |
| Transplant Outdoors | March 29 | Mar 29 – Apr 12 |
| Direct Sow | March 15 | Mar 15 – Apr 5 |
| Harvest | June 28 | Jun 28 – Aug 16 |
| Fall Sowing | September 3 | Sep 3 – Sep 17 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | — |
| 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
228 days in Morris County
Growing Tips for Morris 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 Morris County, NJ?
Morris County is in Zone 6b with an average last frost of March 29. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Morris County, NJ?
Morris County, New Jersey is in USDA Hardiness Zone 6b. The average last spring frost is March 29 and first fall frost is November 12.
Plan Your Garden with Confidence
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