Blog

When to plant Begonias in Marshall County, IL

Marshall County's short 175-day growing season means one Begonias planting between April 28 and May 12. No fall crop in Zone 5b.

When to Plant Begonias in Marshall County, IL

Wax begonias (Begonia × semperflorens) are the workhorse shade bedding plant of American horticulture, offering continuous bloom from transplant to hard frost. Bronze or green-leaved varieties perform well from deep shade to full sun (in northern zones) and tolerate summer humidity better than most cool- season flowers. A staple of mass plantings, containers, and window boxes.

Marshall County, Illinois is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.

At an elevation of 1,177 feet, Marshall County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Begonias to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Marshall County, IL (Zone 5b) Moderate season
175 days
Last Spring Frost April 21
175 growing days
First Fall Frost October 13

Marshall County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Begonias Planting Timeline — Marshall County, IL

Begonias Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors April 28 Apr 28 – May 12
Bloom July 7 Jul 7 – Sep 29

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

175 days in Marshall County

Growing Tips for Marshall County

Start seeds indoors 10–12 weeks before last frost — seed is dust-fine; surface-sow on moist mix under lights, do not cover. Bottom heat (70–75°F) speeds germination. Transplant after frost; begonias are not direct-sown in practice. Pinch seedlings once for branching. Keep soil evenly moist; avoid waterlogged conditions. Bronze-leaf types tolerate more sun; green- leaf types prefer shade to part-sun.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Begonias in Marshall County, IL?

Marshall County is in Zone 5b with an average last frost of April 21. Plan your Begonias planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marshall County, IL?

Marshall County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 13.

When should I plant Begonias in Marshall County, IL?

In Marshall County, IL, plant Begonias after the last frost (around April 21) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Marshall County, IL for Begonias?

Marshall County sits in USDA Zone 5b. Begonias grows reliably in zones 2a through 11b, so it's a good fit here.

Can Begonias grow in Marshall County's climate?

Yes — Begonias grows well in Marshall County's temperate climate. Marshall County averages a 175-day frost-free season, with last frost around April 21 and first frost around October 13.

🌱

Your Marshall County Garden Planner — Free

A 22-page printable planner built for Marshall County (Zone 5b). 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 Marshall County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

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