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When to plant Bachelor's Button in Phillips County County,

Phillips County County's climate puts the Bachelor's Button spring window between April 13 and May 4. time plantings around the expected last-frost window for best survival.

When to Plant Bachelor's Button in Phillips County, CO

Phillips County, Colorado Zone 5b June

Top priorities for Phillips County, Colorado gardeners in June

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

Avg. last frost May 4
Avg. first frost October 7
Soil temp (4") 54°F
Watering High
Pest pressure High
Daylight 14.9 hrs
  1. Start bachelor's button indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

Coming up in July — start thinking about
  • First harvests: bachelor's button

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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.

Phillips County, Colorado is in USDA Zone 5b. The average last spring frost is May 4 and the first fall frost is October 7, giving you a growing season of approximately 156 days.

At an elevation of 5,494 feet, Phillips County receives approximately 21.1 inches of rainfall annually with predominantly 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
Phillips County, CO (Zone 5b) Moderate season
156 days
Last Spring Frost May 4
156 growing days
First Fall Frost October 7

Phillips County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Bachelor's Button Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🌸 Bloom: Jul 2 – Sep 17
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Mar 23 Transplant: May 4 🌸 Bloom: Jul 6 – Sep 21
Safe Start (90%) ✓ Fits season (11 days to spare)
Start indoors: Apr 7 Transplant: May 19 🌸 Bloom: Jul 21 – Oct 6

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 Phillips County

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

Soil pH

Your soil pH (6.5–7.8) overlaps with Bachelor's Button's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Bachelor's Button.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Bachelor's Button.

How to Plant Bachelor's Button

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

Succession Planting Bachelor's Button

3
successive plantings in your 156-day season

Sow every 6.9 weeks. Last sowing by Jul 09 to harvest before frost.

Bachelor's Button Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 136 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.9" 0" ❄️ Dormant
May 2.2" 2.8" 0" ✅ Rainfall sufficient
Jun 2.2" 1.5" 0.7" 💧 Light watering
Jul 2.2" 1.6" 0.6" 💧 Light watering
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 2.2" 1.8" 0.4" 💧 Light watering
Nov 1.7" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Phillips 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 2,379 GDD Excellent fit

Bachelor's Button Planting Timeline — Phillips County, CO

Bachelor's Button Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors May 4 May 4 – May 18
Direct Sow April 13 Apr 13 – May 4
Bloom July 6 Jul 6 – Sep 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

156 days in Phillips County

Growing Tips for Bachelor's Button in Phillips County

Direct sow Bachelor's Button outdoors after May 04 in Phillips County when soil has warmed and frost danger has passed.

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

Phillips County receives only 21" 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 Phillips County, CO?

Phillips County is in Zone 5b with an average last frost of May 4. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Phillips County, CO?

Phillips County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 4 and first fall frost is October 7.

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

In Phillips County County, , plant Bachelor's Button after the last frost (around May 4) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Phillips County County, for Bachelor's Button?

Phillips County County sits in USDA Zone 5b. Bachelor's Button grows reliably in zones 2a through 11b, so it's a good fit here.

Can Bachelor's Button grow in Phillips County County's climate?

Yes — Bachelor's Button grows well in Phillips County County's temperate climate. Phillips County County averages a 156-day frost-free season, with last frost around May 4 and first frost around October 7.

🌱

Your Phillips County Garden Planner — Free

A 22-page printable planner built for Phillips County (Zone 5b). 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 Phillips County, CO. 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.