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When to Plant Bachelor's Button in Harney County, OR

Harney County, Oregon Zone 6a July

Harney County, Oregon gardeners: here's your July plan

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost June 17
Avg. first frost September 6
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs

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Bachelor's Button (Centaurea cyanus), also called cornflower, is a carefree cool-season annual best known for its vivid cobalt-blue flowers — one of the truest blues in the annual garden. It tolerates light frosts, self-seeds prolifically, and thrives in poor to average soils. A traditional cut flower and pollinator magnet, it has been cultivated in gardens for centuries.

Harney County, Oregon is in USDA Zone 6a. The average last spring frost is June 17 and the first fall frost is September 6, giving you a growing season of approximately 81 days.

At an elevation of 679 feet, Harney County receives approximately 22.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Bachelor's Button during the growing season.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Harney County, OR (Zone 6a) Very short season
81 days
Last Spring Frost June 17
81 growing days
First Fall Frost September 6

Harney County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.4

Drainage

Well Drained

Bachelor's Button Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 1 Transplant: Jun 12 🌸 Bloom: Aug 14 – Oct 30
Recommended (50%) ✗ May not fit
Start indoors: May 6 Transplant: Jun 17 🌸 Bloom: Aug 19 – Nov 4
Safe Start (90%) ✗ May not fit
Start indoors: May 13 Transplant: Jun 24 🌸 Bloom: Aug 26 – Nov 11

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 Harney County

How your county's soil matches Bachelor's Button's growing requirements.

Soil pH

Your soil pH (5.6–6.4) overlaps with Bachelor's Button's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Harney County is excellent for Bachelor's Button — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.5%) — Bachelor's Button will thrive.

How to Plant Bachelor's Button

0.3"
Planting Depth
12"
Between Plants
12"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Bachelor's Button Water Budget

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

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

Monthly Watering Guide for Bachelor's Button

Bachelor's Button 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 Bachelor's Button Needs Rainfall You Supplement Action
Jan 3.3" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 1.4" 0" ❄️ Dormant
Jun 2.2" 0.9" 1.3" 🚿 Regular watering
Jul 2.2" 0.4" 1.8" 🚿 Regular watering
Aug 2.2" 0.4" 1.8" 🚿 Regular watering
Sep 2.2" 0.9" 1.3" 🚿 Regular watering
Oct 2" 0" ❄️ Dormant
Nov 3.6" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

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

Bachelor's Button 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.

Bachelor's Button needs ~1,144 GDD — county provides 1,235 GDD Good fit

Bachelor's Button Planting Timeline — Harney County, OR

Bachelor's Button Planting Calendar

Activity When Date Range
Start Indoors May 6 May 6 – May 20
Transplant Outdoors June 17 Jun 17 – Jul 1
Direct Sow May 20 May 20 – Jun 10
Bloom August 19 Aug 19 – Nov 4
Fall Sowing July 26 Jul 26 – Aug 9

Plant 0.3" deep · 12" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

81 days in Harney County

Growing Tips for Bachelor's Button in Harney County

Direct sow Bachelor's Button outdoors after June 17 in Harney County when soil has warmed and frost danger has passed.

Your 81.0-day growing season in Harney County is tight for Bachelor's Button (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Bachelor's Button in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Harney County receives only 22" of rain annually. Bachelor's Button needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct-sow in early spring as soon as soil can be worked; seeds need a brief cold period for best germination (refrigerate for a few days before planting if spring arrives quickly). In zones 6+, fall-sow for the earliest spring bloom. Thin to 12 inches; do not over-fertilize — too much nitrogen produces foliage at the expense of flowers. Deadhead to prolong blooming or allow self-seeding for a naturalized colony.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bachelor's Button in Harney County, OR?

Harney County is in Zone 6a with an average last frost of June 17. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harney County, OR?

Harney County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 17 and first fall frost is September 6.

🌱

Your Harney County Garden Planner — Free

A 22-page printable planner built for Harney 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 Harney 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.