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When to Plant Scallions in Whiteside County, IL

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.

Whiteside County, Illinois is in USDA Zone 5a. The average last spring frost is April 16 and the first fall frost is October 16, giving you a growing season of approximately 183 days.

At an elevation of 682 feet, Whiteside County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Scallions to ensure they mature before fall.

Whiteside County, IL (Zone 5a) Moderate season
183 days
Last Spring Frost April 16
183 growing days
First Fall Frost October 16

Whiteside County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (100 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 3
Recommended (50%) ✓ Fits season (99 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Jul 9
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 27 – Jul 25

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 500 gal / 100 sq ft
Scallions needs ~780 GDD — county provides 2,379 GDD Excellent fit

Scallions Planting Timeline โ€” Whiteside County, IL

Scallions Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 2 Apr 2 โ€“ Apr 23
Fall Sowing August 7 Aug 7 โ€“ Aug 21
Harvest June 11 Jun 11 โ€“ Jul 9

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“70 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

183 days

Growing Tips for Whiteside County

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

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Frequently Asked Questions

When should I plant Scallions in Whiteside County, IL?

Whiteside County is in Zone 5a with an average last frost of April 16. Plan your Scallions planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Whiteside County, IL?

Whiteside County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 16 and first fall frost is October 16.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Whiteside County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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 Whiteside County, IL. Local conditions may vary. Last updated: April 2026.