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When to Plant Columbine in Coos County, OR

Coos County, Oregon Zone 9a June

Your June game plan for Coos County, Oregon

Here's what deserves your attention in Coos County, Oregon this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost March 22
Avg. first frost November 19
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 15.2 hrs

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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.

Coos County, Oregon is in USDA Zone 9a. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Columbine during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Coos County, OR (Zone 9a) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Columbine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (183 days to spare)
Start indoors: Jan 10 Transplant: Feb 21 🌸 Bloom: Apr 11 – May 2
Recommended (50%) ✓ Fits season (186 days to spare)
Start indoors: Jan 25 Transplant: Mar 8 🌸 Bloom: Apr 26 – May 17
Safe Start (90%) ✓ Fits season (181 days to spare)
Start indoors: Feb 25 Transplant: Apr 8 🌸 Bloom: May 27 – Jun 17

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 Coos County

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Columbine's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Columbine will thrive.

How to Plant Columbine

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

Succession Planting Columbine

4
successive plantings in your 242-day season

Sow every 8 weeks. Last sowing by Aug 11 to harvest before frost.

Columbine Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 703 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 5.5" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.8" 3.5" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 5.9" 0" ✅ Rainfall sufficient
Dec 5.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Coos 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 ~1,424 GDD — county provides 4,053 GDD Excellent fit

Columbine Planting Timeline — Coos County, OR

Columbine Planting Calendar

Activity When Date Range
Start Indoors January 25 Jan 25 – Feb 8
Transplant Outdoors March 8 Mar 8 – Mar 22
Direct Sow March 8 Mar 8 – Mar 29
Bloom April 26 Apr 26 – May 17

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April Bloom
May Bloom
June
July
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 9a

📆 Growing Season

242 days in Coos County

Growing Tips for Columbine in Coos County

Direct sow Columbine outdoors after March 22 in Coos 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 Coos County, OR?

Coos County is in Zone 9a with an average last frost of March 22. Plan your Columbine planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coos County, OR?

Coos County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is March 22 and first fall frost is November 19.

🌱

Your Coos County Garden Planner — Free

A 22-page printable planner built for Coos County (Zone 9a). 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 Coos County, OR. 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.