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When to Plant Scallions in Henry County, MO

Henry County, Missouri Zone 6b May

This month in Henry County, Missouri

Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 14
Avg. first frost October 22
Soil temp (4") 63°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Sow scallions in trays indoors

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Coming up in June — start thinking about
  • First harvests: scallions

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Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.

Henry County, Missouri is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 22, giving you a growing season of approximately 191 days.

At an elevation of 1,388 feet, Henry County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Scallions during the growing season.

Henry County, MO (Zone 6b) Moderate season
191 days
Last Spring Frost April 14
191 growing days
First Fall Frost October 22

Henry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (106 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 1
Recommended (50%) ✓ Fits season (107 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: Jun 9 – Jul 7
Safe Start (90%) ✓ Fits season (104 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 26 – Jul 24

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 Henry County

How your county's soil matches Scallions's growing requirements.

Soil pH

Your soil pH (5.7–6.6) overlaps with Scallions's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Henry County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Scallions.

How to Plant Scallions

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Scallions

4
successive plantings in your 191-day season

Sow every 5.7 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Aug 13.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 196 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Scallions

Scallions needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Scallions Needs Rainfall You Supplement Action
Jan 1.9" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 5.1" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Henry County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Scallions 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.

Scallions needs ~825 GDD — county provides 2,626 GDD Excellent fit

Scallions Planting Timeline — Henry County, MO

Scallions Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 14 Apr 14 – Apr 28
Direct Sow March 31 Mar 31 – Apr 21
Harvest June 9 Jun 9 – Jul 7
Fall Sowing August 13 Aug 13 – Aug 27

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

191 days in Henry County

Growing Tips for Scallions in Henry County

Direct sow Scallions outdoors after April 14 in Henry County when soil has warmed and frost danger has passed.

Common pests for Scallions in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Scallions in Henry County, MO?

Henry County is in Zone 6b with an average last frost of April 14. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henry County, MO?

Henry County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 22.

🌱

Your Henry County Garden Planner — Free

A 24-page printable planner built for Henry County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Henry County, MO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.