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When to plant Zinnia in Morgan County, IL

Plant Zinnia in Morgan County after April 14; the prime window is April 21–May 12.

When to Plant Zinnia in Morgan County, IL

Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Morgan County, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 1,348 feet, Morgan County receives approximately 39.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Zinnia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Morgan County, IL (Zone 6a) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Morgan County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Zinnia Planting Timeline — Morgan County, IL

Zinnia Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 21 Apr 21 – May 12
Bloom June 30 Jun 30 – Oct 6

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

186 days in Morgan County

Growing Tips for Morgan County

Direct-sow after last frost when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Morgan County, IL?

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

What planting zone is Morgan County, IL?

Morgan County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 17.

When should I plant Zinnia in Morgan County, IL?

In Morgan County, IL, plant Zinnia after the last frost (around April 14) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Morgan County, IL for Zinnia?

Morgan County sits in USDA Zone 6a. Zinnia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zinnia grow in Morgan County's climate?

Yes — Zinnia grows well in Morgan County's temperate climate. Morgan County averages a 186-day frost-free season, with last frost around April 14 and first frost around October 17.

🌱

Your Morgan County Garden Planner — Free

A 22-page printable planner built for Morgan County (Zone 6a). 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 Morgan County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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