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When to plant Columbine in Union County County,

The best window to plant Columbine in Union County County, is May 9–May 30, when soil warms to 50°F. Last frost typically hits April 25; first frost October 17.

When to Plant Columbine in Union County, IN

Union County, Indiana Zone 6a June

June in the garden — Union County, Indiana

Your Union County, Indiana garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 25
Avg. first frost October 17
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs
  1. Get columbine seeds going inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

July prep starts now
  • First harvests: columbine

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Wild Columbine (Aquilegia canadensis) is a graceful native perennial of eastern North America, producing distinctive nodding flowers with spurred red-and-yellow petals that are irresistible to hummingbirds and native bees in spring. Its blue-green, fernlike foliage remains attractive long after flowering. Garden hybrid columbines (A. x hybrida) extend the color palette to the full spectrum and are equally adaptable. Short-lived by perennial standards (3–4 years per plant), but prolific self-seeders that perpetuate themselves and even hybridize freely in the garden, creating ever-evolving color combinations. An ideal woodland edge and cottage garden plant.

Union County, Indiana is in USDA Zone 6a. The average last spring frost is April 25 and the first fall frost is October 17, giving you a growing season of approximately 175 days.

At an elevation of 506 feet, Union County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Columbine during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Union County, IN (Zone 6a) Moderate season
175 days
Last Spring Frost April 25
175 growing days
First Fall Frost October 17
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Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.2

Drainage

Well Drained

Columbine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (72 days to spare)
Start indoors: Feb 13 Transplant: May 1 🌸 Bloom: Jun 26 – Jul 31
Recommended (50%) ✓ Fits season (70 days to spare)
Start indoors: Feb 21 Transplant: May 9 🌸 Bloom: Jul 4 – Aug 8
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Mar 7 Transplant: May 23 🌸 Bloom: Jul 18 – Aug 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 Union County

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

Soil pH

Your soil pH (5.7–7.2) overlaps with Columbine's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Columbine.

Organic Matter

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

How to Plant Columbine

0.1"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Columbine

2
successive plantings in your 175-day season

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

Columbine Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 773 gal / 100 sq ft

Monthly Watering Guide for Columbine

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

Month Columbine Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 3.6" 0.7" 💧 Light watering
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.1" 1.2" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Columbine 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.

Columbine needs ~1,488 GDD — county provides 3,062 GDD Excellent fit

Columbine Planting Timeline — Union County, IN

Columbine Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors May 9 May 9 – May 23
Direct Sow May 9 May 9 – May 30
Bloom July 4 Jul 4 – Aug 8

Plant 0.1" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

175 days in Union County

Growing Tips for Columbine in Union County

Direct sow Columbine outdoors after April 25 in Union County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 8–10 weeks before last frost with 4–6 weeks of cold moist stratification first (mix seeds with moist perlite in a bag and refrigerate), or direct-sow outdoors in fall for natural stratification. Transplant to the garden 2–4 weeks after last frost in spring. Prefers cool, moist, well-drained soil with morning sun and afternoon shade, especially in Zones 6+. After bloom, allow seed pods to mature and scatter if you want natural self-seeding; deadhead if you want to prevent spreading. Individual plants are typically short-lived (3–5 years) but colonies persist through prolific self-seeding. Leafminers may create white tunnels in foliage — unsightly but rarely serious. Year 2+ plants flower most profusely.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Columbine in Union County, IN?

Union County is in Zone 6a with an average last frost of April 25. Plan your Columbine planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, IN?

Union County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 25 and first fall frost is October 17.

When should I plant Columbine in Union County County, ?

In Union County County, , plant Columbine after the last frost (around April 25) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Union County County, for Columbine?

Union County County sits in USDA Zone 6a. Columbine grows reliably in zones 3a through 9a, so it's a good fit here.

Can Columbine grow in Union County County's climate?

Yes — Columbine grows well in Union County County's temperate climate. Union County County averages a 175-day frost-free season, with last frost around April 25 and first frost around October 17.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union 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 Union County, IN. 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.