When to plant Onion in Dunklin County, MO
Dunklin County's spring Onion window runs March 13 through April 3. most warm-season crops establish quickly once soil holds above 60°F. A second sowing from August 24 to September 7 extends the harvest into fall.
When to Plant Onion in Dunklin County, MO
What to do in July
If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.
-
Basket week: onion
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Coming up in August — start thinking about
- First harvests: onion
- Fall sowing: onion
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.
Dunklin County, Missouri is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is November 2, giving you a growing season of approximately 220 days.
At an elevation of 1,344 feet, Dunklin County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Onion during the growing season.
Dunklin County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-7.1
Drainage
Well Drained
Onion 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 Dunklin County
How your county's soil matches Onion's growing requirements.
Soil pH
Your soil pH (5.6–7.1) overlaps with Onion's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Dunklin County is excellent for Onion — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Onion.
How to Plant Onion
Fall planting: Sow 10 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Apr | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Dunklin 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 — Dunklin County, MO
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 20 | Feb 20 – Mar 6 |
| Transplant Outdoors | March 27 | Mar 27 – Apr 10 |
| Direct Sow | March 13 | Mar 13 – Apr 3 |
| Harvest | June 26 | Jun 26 – Aug 14 |
| Fall Sowing | August 24 | Aug 24 – Sep 7 |
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 | Fall Sowing Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
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: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
220 days in Dunklin County
Growing Tips for Onion in Dunklin County
Direct sow Onion outdoors after March 27 in Dunklin County when soil has warmed and frost danger has passed.
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
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 Dunklin County, MO?
Dunklin County is in Zone 7b with an average last frost of March 27. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dunklin County, MO?
Dunklin County, Missouri is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is November 2.
When should I plant Onion in Dunklin County, MO?
In Dunklin County, MO, plant Onion after the last frost (around March 27) and before the first frost (around November 2). Best results when soil holds above 50°F.
What growing zone is Dunklin County, MO for Onion?
Dunklin County sits in USDA Zone 7b. Onion grows reliably in zones 3a through 10b, so it's a good fit here.
Can Onion grow in Dunklin County's climate?
Yes — Onion grows well in Dunklin County's temperate climate. Dunklin County averages a 220-day frost-free season, with last frost around March 27 and first frost around November 2.
Your Dunklin County Garden Planner — Free
A 22-page printable planner built for Dunklin County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.