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When to Plant Gaillardia (Blanket Flower) in Clackamas County, OR

Clackamas County, Oregon Zone 9a July

July to-do list for Clackamas County, Oregon

Each item below is timed to Clackamas County, Oregon's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 14
Avg. first frost October 28
Soil temp (4") 88°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
  1. Bring in the gaillardia (blanket flower)

    If you can't use it all right away, check the food-preservation section of your planner.

A few tasks this July that'll pay off in August
  • First harvests: gaillardia (blanket flower)

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Gaillardia (Gaillardia aristata), the native blanket flower of the American West, is one of the most floriferous and longest-blooming perennials available — producing cheerful, daisy-like flowers in fiery red, orange, and yellow combinations from early summer through hard frost in most climates. Named for the way its spreading colonies mimic the patterned blankets of Indigenous American weavers, gaillardia thrives in the exact conditions that challenge other perennials: poor, dry, gravelly soil in full sun. An outstanding pollinator plant, attracting bees, butterflies, and finches that feed on its seed heads. Somewhat short-lived (3–5 years) but self-seeds freely to sustain garden colonies.

Clackamas County, Oregon is in USDA Zone 9a. The average last spring frost is April 14 and the first fall frost is October 28, giving you a growing season of approximately 197 days.

At an elevation of 199 feet, Clackamas County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Gaillardia (Blanket Flower) during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Gaillardia (Blanket Flower) root diseases.

Perennial Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting
Clackamas County, OR (Zone 9a) Moderate season
197 days
Last Spring Frost April 14
197 growing days
First Fall Frost October 28

Clackamas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Gaillardia (Blanket Flower) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 21 Transplant: Mar 21 🌸 Bloom: May 30 – Nov 28
Recommended (50%) ✗ May not fit
Start indoors: Mar 3 Transplant: Mar 31 🌸 Bloom: Jun 9 – Dec 8
Safe Start (90%) ✗ May not fit
Start indoors: Mar 26 Transplant: Apr 23 🌸 Bloom: Jul 2 – Dec 31

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 Clackamas County

How your county's soil matches Gaillardia (Blanket Flower)'s growing requirements.

Soil pH

Your soil pH (5.7–6.3) overlaps with Gaillardia (Blanket Flower)'s range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Clackamas County is excellent for Gaillardia (Blanket Flower) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) — Gaillardia (Blanket Flower) will thrive.

How to Plant Gaillardia (Blanket Flower)

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

Succession Planting Gaillardia (Blanket Flower)

3
successive plantings in your 197-day season

Sow every 8 weeks. Last sowing by Jul 20 to harvest before frost.

Gaillardia (Blanket Flower) Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Gaillardia (Blanket Flower)

Gaillardia (Blanket Flower) needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Gaillardia (Blanket Flower) Needs Rainfall You Supplement Action
Jan 8.3" 0" ❄️ Dormant
Feb 5.3" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 2.2" 4" 0" ✅ Rainfall sufficient
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 2.1" 0.1" 💧 Light watering
Jul 2.2" 0.8" 1.4" 🚿 Regular watering
Aug 2.2" 1" 1.2" 🚿 Regular watering
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 2.2" 4.7" 0" ✅ Rainfall sufficient
Nov 8.2" 0" ❄️ Dormant
Dec 8.5" 0" ❄️ Dormant

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

Gaillardia (Blanket Flower) 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.

Gaillardia (Blanket Flower) needs ~1,169 GDD — county provides 2,708 GDD Excellent fit

Gaillardia (Blanket Flower) Planting Timeline — Clackamas County, OR

Gaillardia (Blanket Flower) Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors March 31 Mar 31 – Apr 14
Direct Sow March 31 Mar 31 – Apr 21
Bloom June 9 Jun 9 – Dec 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

197 days in Clackamas County

Growing Tips for Gaillardia (Blanket Flower) in Clackamas County

Direct sow Gaillardia (Blanket Flower) outdoors after April 14 in Clackamas County when soil has warmed and frost danger has passed.

Common pests for Gaillardia (Blanket Flower) in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6–8 weeks before last frost or direct-sow after last frost. Seeds need light to germinate — press onto soil surface without covering, or cover very lightly (1/8 inch). Transplant after last frost when soil has warmed. Lean, well-drained soil is essential — rich or wet soil causes sprawl and root rot. Deadhead spent blooms to prolong the season, but leave some heads for self-seeding to renew the planting. Divide every 2–3 years in spring to maintain vigor. Drought-tolerant once established; overwatering is more damaging than underwatering. Year 2+ plants deliver the fullest multi-season bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Gaillardia (Blanket Flower) in Clackamas County, OR?

Clackamas County is in Zone 9a with an average last frost of April 14. Plan your Gaillardia (Blanket Flower) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clackamas County, OR?

Clackamas County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 14 and first fall frost is October 28.

🌱

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A 22-page printable planner built for Clackamas 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 Clackamas County, OR. 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.