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When to plant Impatiens in Hardin County, IL

Hardin County's short 210-day growing season means one Impatiens planting between April 11 and April 25. No fall crop in Zone 7a.

When to Plant Impatiens in Hardin County, IL

Hardin County, Illinois Zone 7a July

What to do in July

We've pulled the most time-sensitive tasks for Hardin County, Illinois this July and put them front and centre. Tackle them in order.

Avg. last frost April 4
Avg. first frost October 31
Soil temp (4") 79°F
Watering Moderate
Pest pressure High
Daylight 14.3 hrs
  1. Harvest impatiens as they ripen

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

Looking ahead to August
  • 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.

Hardin County, Illinois is in USDA Zone 7a. The average last spring frost is April 4 and the first fall frost is October 31, giving you a growing season of approximately 210 days.

At an elevation of 1,218 feet, Hardin County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Impatiens during the growing season.

Annual Blooms in Summer Pollinator-friendly
Hardin County, IL (Zone 7a) Long season
210 days
Last Spring Frost April 4
210 growing days
First Fall Frost October 31

Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Impatiens Planting Risk Windows

Early Start (70% safe) ✓ Fits season (19 days to spare)
Start indoors: Jan 31 Transplant: Apr 4 🌸 Bloom: Jun 13 – Oct 3
Recommended (50%) ✓ Fits season (21 days to spare)
Start indoors: Feb 7 Transplant: Apr 11 🌸 Bloom: Jun 20 – Oct 10
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Feb 20 Transplant: Apr 24 🌸 Bloom: Jul 3 – Oct 23

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 Hardin County

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

Soil pH

Your soil pH (6.2–7.2) 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 Hardin County is excellent for Impatiens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) — Impatiens will thrive.

How to Plant Impatiens

10"
Between Plants
12"
Between Rows

Succession Planting Impatiens

4
successive plantings in your 210-day season

Sow every 6.9 weeks. Last sowing by Aug 17 to harvest before frost.

Impatiens Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 740 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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.1" 1.2" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hardin 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 ~1,080 GDD — county provides 3,360 GDD Excellent fit

Impatiens Planting Timeline — Hardin County, IL

Impatiens Planting Calendar

Activity When Date Range
Start Indoors February 7 Feb 7 – Feb 21
Transplant Outdoors April 11 Apr 11 – Apr 25
Bloom June 20 Jun 20 – Oct 10

· 10" apart · Rows 12" 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

60–75 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

210 days in Hardin County

Growing Tips for Impatiens in Hardin County

Direct sow Impatiens outdoors after April 04 in Hardin 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 Hardin County, IL?

Hardin County is in Zone 7a with an average last frost of April 4. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hardin County, IL?

Hardin County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 4 and first fall frost is October 31.

When should I plant Impatiens in Hardin County, IL?

In Hardin County, IL, plant Impatiens after the last frost (around April 4) and before the first frost (around October 31). Best results when soil holds above 50°F.

What growing zone is Hardin County, IL for Impatiens?

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

Can Impatiens grow in Hardin County's climate?

Yes — Impatiens grows well in Hardin County's temperate climate. Hardin County averages a 210-day frost-free season, with last frost around April 4 and first frost around October 31.

🌱

Your Hardin County Garden Planner — Free

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

Sources & credits

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