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When to plant Begonias in Monroe County, IL

Plant Begonias in Monroe County during the brief April 14–April 28 window. With 193 frost-free days, fall plantings can't mature before October 24.

When to Plant Begonias in Monroe County, IL

Monroe County, Illinois Zone 7a June

Your June gardening checklist

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

Avg. last frost April 14
Avg. first frost October 24
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Get begonias seeds going inside

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

  2. Harvest begonias as they ripen

    If you can't use it all right away, check the food-preservation section of your planner.

To set up a strong July, finish these tasks
  • First harvests: begonias

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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.

Monroe County, Illinois is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.

At an elevation of 1,278 feet, Monroe County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Begonias during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Monroe County, IL (Zone 7a) Moderate season
193 days
Last Spring Frost April 14
193 growing days
First Fall Frost October 24

Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Begonias Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Jan 26 Transplant: Apr 6 🌸 Bloom: Jun 15 – Oct 5
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Feb 3 Transplant: Apr 14 🌸 Bloom: Jun 23 – Oct 13
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Feb 14 Transplant: Apr 25 🌸 Bloom: Jul 4 – Oct 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 Monroe County

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Begonias's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Begonias will thrive.

How to Plant Begonias

8"
Between Plants
10"
Between Rows

Succession Planting Begonias

3
successive plantings in your 193-day season

Sow every 8 weeks. Last sowing by Jul 26 to harvest before frost.

Begonias 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 527 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Begonias

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

Month Begonias Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Begonias 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.

Begonias needs ~1,280 GDD — county provides 3,088 GDD Excellent fit

Begonias Planting Timeline — Monroe County, IL

Begonias Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 – Feb 17
Transplant Outdoors April 14 Apr 14 – Apr 28
Bloom June 23 Jun 23 – Oct 13

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

193 days in Monroe County

Growing Tips for Begonias in Monroe County

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

General growing tips

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 Monroe County, IL?

Monroe County is in Zone 7a with an average last frost of April 14. Plan your Begonias planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, IL?

Monroe County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.

When should I plant Begonias in Monroe County, IL?

In Monroe County, IL, plant Begonias after the last frost (around April 14) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Monroe County, IL for Begonias?

Monroe County sits in USDA Zone 7a. Begonias grows reliably in zones 2a through 11b, so it's a good fit here.

Can Begonias grow in Monroe County's climate?

Yes — Begonias grows well in Monroe County's temperate climate. Monroe County averages a 193-day frost-free season, with last frost around April 14 and first frost around October 24.

🌱

Your Monroe County Garden Planner — Free

A 22-page printable planner built for Monroe 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 Monroe County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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