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When to Plant Columbine in Delaware County, OK

Delaware County, Oklahoma Zone 7a June

This month in Delaware County, Oklahoma

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

Avg. last frost April 9
Avg. first frost October 25
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Start columbine under lights

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

  2. Collect columbine at their peak

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

Get ahead of July
  • 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.

Delaware County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 440 feet, Delaware County receives approximately 30.3 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Columbine during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Delaware County, OK (Zone 7a) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25

Delaware County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Columbine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Start indoors: Feb 6 Transplant: Apr 10 🌸 Bloom: May 29 – Jul 3
Recommended (50%) ✓ Fits season (108 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🌸 Bloom: Jun 4 – Jul 9
Safe Start (90%) ✓ Fits season (110 days to spare)
Start indoors: Feb 26 Transplant: Apr 30 🌸 Bloom: Jun 18 – Jul 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 Delaware County

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

Soil pH

Your soil pH (6.3–7.6) overlaps with Columbine's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Columbine.

How to Plant Columbine

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

Succession Planting Columbine

3
successive plantings in your 199-day season

Sow every 8 weeks. Last sowing by Jul 17 to harvest before frost.

Columbine 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 766 gal / 100 sq ft
Drought risk

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

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 0.7" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.8" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Delaware 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 ~1,742 GDD — county provides 4,079 GDD Excellent fit

Columbine Planting Timeline — Delaware County, OK

Columbine Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 – Feb 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 16 Apr 16 – May 7
Bloom June 4 Jun 4 – Jul 9

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

Month-by-Month Timeline

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

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 7a

📆 Growing Season

199 days in Delaware County

Growing Tips for Columbine in Delaware County

Direct sow Columbine outdoors after April 09 in Delaware 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 Delaware County, OK?

Delaware County is in Zone 7a with an average last frost of April 9. Plan your Columbine planting based on this frost date — see the calendar above for exact timing.

What planting zone is Delaware County, OK?

Delaware County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 25.

🌱

Your Delaware County Garden Planner — Free

A 22-page printable planner built for Delaware 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 Delaware County, OK. 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.