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When to plant Impatiens in McDonough County, IL

In McDonough County, Impatiens is a single-season spring crop — there's no second fall window. Plant April 24–May 8 for an 60–75-day harvest, finishing well before the October 17 first frost.

When to Plant Impatiens in McDonough County, IL

McDonough County, Illinois Zone 6a July

July in McDonough County, Illinois — your action list

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

Avg. last frost April 17
Avg. first frost October 17
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Start harvesting impatiens

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Coming up in August — start thinking about
  • First harvests: impatiens

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Impatiens (Impatiens walleriana) are the go-to annual for shaded beds and containers. They produce a continuous carpet of flat-faced blooms from transplant until frost, needing little deadheading. Their preference for consistent moisture and part-shade makes them ideal under trees and along north-facing borders.

McDonough County, Illinois is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.

At an elevation of 738 feet, McDonough County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Impatiens to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly
McDonough County, IL (Zone 6a) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17

McDonough County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Impatiens Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Feb 14 Transplant: Apr 18 🌸 Bloom: Jun 27 – Oct 3
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Feb 20 Transplant: Apr 24 🌸 Bloom: Jul 3 – Oct 9
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Mar 5 Transplant: May 7 🌸 Bloom: Jul 16 – Oct 22

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 McDonough County

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

Soil pH

Your soil pH (6.2–7.3) is more alkaline than Impatiens prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Impatiens.

Organic Matter

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

How to Plant Impatiens

10"
Between Plants
12"
Between Rows

Succession Planting Impatiens

3
successive plantings in your 183-day season

Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.

Impatiens Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 723 gal / 100 sq ft

Monthly Watering Guide for Impatiens

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

Month Impatiens Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.8" 0" ✅ Rainfall sufficient
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Impatiens 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.

Impatiens needs ~878 GDD — county provides 2,379 GDD Excellent fit

Impatiens Planting Timeline — McDonough County, IL

Impatiens Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors April 24 Apr 24 – May 8
Bloom July 3 Jul 3 – Oct 9

· 10" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Transplant Outdoors
May Transplant Outdoors
June
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

60–75 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in McDonough County

Growing Tips for Impatiens in McDonough County

Direct sow Impatiens outdoors after April 17 in McDonough County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 8–10 weeks before last frost at 70–75°F; germination requires light — do not cover seeds. Transplant after last frost once nights consistently exceed 50°F. Water regularly — wilting causes bud drop and they rarely fully recover the same flush. Watch for impatiens downy mildew (IDM); consider New Guinea impatiens as a resistant alternative in affected regions. Pinch tips at planting to encourage branching.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Impatiens in McDonough County, IL?

McDonough County is in Zone 6a with an average last frost of April 17. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.

What planting zone is McDonough County, IL?

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

When should I plant Impatiens in McDonough County, IL?

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

What growing zone is McDonough County, IL for Impatiens?

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

Can Impatiens grow in McDonough County's climate?

Yes — Impatiens grows well in McDonough County's temperate climate. McDonough County averages a 183-day frost-free season, with last frost around April 17 and first frost around October 17.

🌱

Your McDonough County Garden Planner — Free

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

Sources & credits

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