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When to Plant Scallions in Franklin County, WA

Franklin County, Washington Zone 7a May

Your May planting checklist for Franklin County, Washington

May is a pivotal month for Franklin County, Washington gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 13
Avg. first frost October 23
Soil temp (4") 66°F
Watering Critical
Pest pressure Moderate
Daylight 14.8 hrs
  1. Indoor seed-starting week for scallions

    Label every cell. You will absolutely forget which is which otherwise.

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.

Franklin County, Washington is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 23, giving you a growing season of approximately 193 days.

At an elevation of 1,556 feet, Franklin County receives approximately 15.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Scallions during the growing season. With low rainfall, drip irrigation is essential for growing Scallions successfully. Mulch heavily to conserve soil moisture.

Franklin County, WA (Zone 7a) Moderate season
193 days
Last Spring Frost April 13
193 growing days
First Fall Frost October 23
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Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Feb 25 Transplant: Apr 1 🍅 Harvest: May 27 – Jun 24
Recommended (50%) ✓ Fits season (109 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 8 – Jul 6
Safe Start (90%) ✓ Fits season (97 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jul 5 – Aug 2

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 Franklin County

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

Soil pH

Your soil pH (5.6–6.6) overlaps with Scallions's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) — Scallions will thrive.

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 193-day season

Sow every 5.7 weeks. Last sowing by Aug 14 to harvest before frost.

For a dedicated fall crop, sow by Aug 14.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,131 gal / 100 sq ft

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 2.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 0.6" 3.7" 🚿 Regular watering
Jul 4.3" 0.2" 4.1" 🚿 Regular watering
Aug 4.3" 0.3" 4" 🚿 Regular watering
Sep 4.3" 0.6" 3.7" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 2.2" 0" ❄️ Dormant
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Franklin 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 ~1,050 GDD — county provides 3,377 GDD Excellent fit

Scallions Planting Timeline — Franklin County, WA

Scallions Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 30 Mar 30 – Apr 20
Harvest June 8 Jun 8 – Jul 6
Fall Sowing August 14 Aug 14 – Aug 28

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
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

193 days in Franklin County

Growing Tips for Scallions in Franklin County

Direct sow Scallions outdoors after April 13 in Franklin 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.

Franklin County receives only 16" of rain annually. Scallions needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Franklin County, WA?

Franklin County is in Zone 7a with an average last frost of April 13. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, WA?

Franklin County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 23.

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Your Franklin County Garden Planner — Free

A 24-page printable planner built for Franklin 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Franklin County, WA. 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.