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When to plant Begonias in Douglas County, IL

Plant Begonias in Douglas County during the brief April 21–May 5 window. With 186 frost-free days, fall plantings can't mature before October 17.

When to Plant Begonias in Douglas County, IL

Douglas County, Illinois Zone 6a June

What to do in June

Each item below is timed to Douglas County, Illinois's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 14
Avg. first frost October 17
Soil temp (4") 68°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs
  1. Fire up the seed-starting tray: begonias

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Harvest begonias as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Before July arrives, get these ready
  • 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.

Douglas 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 1,036 feet, Douglas County receives approximately 30.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Begonias during the growing season.

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

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Begonias Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Jan 29 Transplant: Apr 16 🌸 Bloom: Jun 25 – Sep 24
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Feb 3 Transplant: Apr 21 🌸 Bloom: Jun 30 – Sep 29
Safe Start (90%) ✓ Fits season (18 days to spare)
Start indoors: Feb 17 Transplant: May 5 🌸 Bloom: Jul 14 – Oct 13

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 Douglas County

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

Soil pH

Your soil pH (6.2–7.2) is more alkaline than Begonias prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Begonias will thrive.

How to Plant Begonias

8"
Between Plants
10"
Between Rows

Succession Planting Begonias

3
successive plantings in your 186-day season

Sow every 8 weeks. Last sowing by Jul 19 to harvest before frost.

Begonias Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 600 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 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 3.6" 0.7" 💧 Light watering
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Douglas 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 ~1,220 GDD — county provides 2,836 GDD Excellent fit

Begonias Planting Timeline — Douglas County, IL

Begonias Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 – Feb 17
Transplant Outdoors April 21 Apr 21 – May 5
Bloom June 30 Jun 30 – Sep 29

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6a

📆 Growing Season

186 days in Douglas County

Growing Tips for Begonias in Douglas County

Direct sow Begonias outdoors after April 14 in Douglas 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 Douglas County, IL?

Douglas County is in Zone 6a 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 Douglas County, IL?

Douglas 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 Begonias in Douglas County, IL?

In Douglas County, IL, plant Begonias 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 Douglas County, IL for Begonias?

Douglas County sits in USDA Zone 6a. Begonias grows reliably in zones 2a through 11b, so it's a good fit here.

Can Begonias grow in Douglas County's climate?

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

🌱

Your Douglas County Garden Planner — Free

A 22-page printable planner built for Douglas 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 Douglas 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.