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When to plant Impatiens in Franklin County, IA

Plant Impatiens in Franklin County during the brief May 7–May 21 window. With 160 frost-free days, fall plantings can't mature before October 7.

When to Plant Impatiens in Franklin County, IA

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.

Franklin County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 1,145 feet, Franklin County receives approximately 41.6 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
Franklin County, IA (Zone 5a) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7

Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

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 1.9" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 5.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 4" 0.3" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Impatiens Planting Timeline — Franklin County, IA

Impatiens Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors May 7 May 7 – May 21
Bloom July 16 Jul 16 – Oct 8

· 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–6.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

160 days in Franklin County

Growing Tips for Franklin County

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 Franklin County, IA?

Franklin County is in Zone 5a with an average last frost of April 30. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, IA?

Franklin County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 7.

When should I plant Impatiens in Franklin County, IA?

In Franklin County, IA, plant Impatiens after the last frost (around April 30) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Franklin County, IA for Impatiens?

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

Can Impatiens grow in Franklin County's climate?

Yes — Impatiens grows well in Franklin County's temperate climate. Franklin County averages a 160-day frost-free season, with last frost around April 30 and first frost around October 7.

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Your Franklin County Garden Planner — Free

A 22-page printable planner built for Franklin County (Zone 5a). 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 Franklin County, IA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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