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When to plant Pansy in Hamilton County, IA

Plant Pansy in Hamilton County during the brief May 1–May 15 window. With 159 frost-free days, fall plantings can't mature before October 7.

When to Plant Pansy in Hamilton County, IA

Hamilton County, Iowa Zone 5a July

July in Hamilton County, Iowa — your action list

Your garden in Hamilton County, Iowa is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost May 1
Avg. first frost October 7
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Indoor seed-starting week for pansy

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Harvest pansy as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

August prep starts now
  • First harvests: pansy

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Pansies (Viola × wittrockiana) are beloved cool-season annuals offering some of the widest color range in the annual garden. Their cheerful "faces" appear in early spring — or even late winter in mild climates — and hold up remarkably well through frosts. Heat causes them to go leggy and stop blooming; replace with warm-season annuals once daytime temps exceed 70°F.

Hamilton County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 1,210 feet, Hamilton County receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Pansy to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Good for cutting
Hamilton County, IA (Zone 5a) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Pansy Planting Risk Windows

Early Start (70% safe) ✓ Fits season (49 days to spare)
Start indoors: Feb 13 Transplant: Apr 24 🌸 Bloom: Jun 19 – Aug 14
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Feb 20 Transplant: May 1 🌸 Bloom: Jun 26 – Aug 21
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Mar 5 Transplant: May 14 🌸 Bloom: Jul 9 – Sep 3

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 Hamilton County

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

Soil pH

Your soil pH (5.8–6.8) is more alkaline than Pansy prefers (5.4–6.2). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Pansy.

How to Plant Pansy

0.3"
Planting Depth
7"
Between Plants
10"
Between Rows

Succession Planting Pansy

2
successive plantings in your 159-day season

Sow every 8 weeks. Last sowing by Jul 09 to harvest before frost.

Pansy Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 92 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Pansy

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

Month Pansy Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Pansy 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.

Pansy needs ~800 GDD — county provides 1,590 GDD Excellent fit

Pansy Planting Timeline — Hamilton County, IA

Pansy Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors May 1 May 1 – May 15
Bloom June 26 Jun 26 – Aug 21

Plant 0.3" deep · 7" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.4–6.2 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

159 days in Hamilton County

Growing Tips for Pansy in Hamilton County

Direct sow Pansy outdoors after May 01 in Hamilton County when soil has warmed and frost danger has passed.

General growing tips

Start indoors 10-12 weeks before last frost for spring transplants. In zones 6+, fall planting (8-10 weeks before first frost) gives overwintering plants that bloom earliest in spring. Plant in full sun in cool weather; afternoon shade helps extend bloom in zones 7-8. Deadhead to prevent premature seed set. Shear back by one-third when plants go leggy to extend the season.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pansy in Hamilton County, IA?

Hamilton County is in Zone 5a with an average last frost of May 1. Plan your Pansy planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, IA?

Hamilton County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 7.

When should I plant Pansy in Hamilton County, IA?

In Hamilton County, IA, plant Pansy after the last frost (around May 1) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Hamilton County, IA for Pansy?

Hamilton County sits in USDA Zone 5a. Pansy grows reliably in zones 3a through 10b, so it's a good fit here.

Can Pansy grow in Hamilton County's climate?

Yes — Pansy grows well in Hamilton County's temperate climate. Hamilton County averages a 159-day frost-free season, with last frost around May 1 and first frost around October 7.

🌱

Your Hamilton County Garden Planner — Free

A 22-page printable planner built for Hamilton 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 Hamilton County, IA. 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.