When to plant Onion in Jasper County, MO
Jasper County's climate puts the Onion spring window between March 26 and April 16. most warm-season crops establish quickly once soil holds above 60°F. A second sowing from August 17 to August 31 extends the harvest into fall.
When to Plant Onion in Jasper County, MO
What to do in August
Here's what deserves your attention in Jasper County, Missouri this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
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Harvest onion as they ripen
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
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Kick off the fall garden with onion
Keep young seedlings shaded and moist in summer heat. A row of taller crops works as natural shade.
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.
Jasper County, Missouri is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 26, giving you a growing season of approximately 200 days.
At an elevation of 1,156 feet, Jasper County receives approximately 30.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Onion during the growing season.
Jasper County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.6
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 Jasper County
How your county's soil matches Onion's growing requirements.
Soil pH
Your soil pH (5.5–6.6) overlaps with Onion's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Jasper 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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| May | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Aug | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Sep | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Oct | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Jasper 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 — Jasper County, MO
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 5 | Mar 5 – Mar 19 |
| Transplant Outdoors | April 9 | Apr 9 – Apr 23 |
| Direct Sow | March 26 | Mar 26 – Apr 16 |
| Harvest | July 9 | Jul 9 – Aug 27 |
| Fall Sowing | August 17 | Aug 17 – Aug 31 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| 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 7a
📆 Growing Season
200 days in Jasper County
Growing Tips for Onion in Jasper County
Direct sow Onion outdoors after April 09 in Jasper 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 Jasper County, MO?
Jasper County is in Zone 7a with an average last frost of April 9. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jasper County, MO?
Jasper County, Missouri is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 26.
When should I plant Onion in Jasper County, MO?
In Jasper County, MO, plant Onion after the last frost (around April 9) and before the first frost (around October 26). Best results when soil holds above 50°F.
What growing zone is Jasper County, MO for Onion?
Jasper County sits in USDA Zone 7a. Onion grows reliably in zones 3a through 10b, so it's a good fit here.
Can Onion grow in Jasper County's climate?
Yes — Onion grows well in Jasper County's temperate climate. Jasper County averages a 200-day frost-free season, with last frost around April 9 and first frost around October 26.
Your Jasper County Garden Planner — Free
A 22-page printable planner built for Jasper County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.