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When to Plant Bachelor's Button in Summit County, UT

Summit County, Utah Zone 5b June

June to-do list for Summit County, Utah

Your garden in Summit County, Utah is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost June 10
Avg. first frost September 12
Soil temp (4") 45°F
Watering High
Pest pressure High
Daylight 14.9 hrs
  1. Time to transplant bachelor's button

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

Before July arrives, get these ready
  • Starting indoors: 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.

Summit County, Utah is in USDA Zone 5b. The average last spring frost is June 10 and the first fall frost is September 12, giving you a growing season of approximately 94 days.

At an elevation of 8,145 feet, Summit County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Bachelor's Button during the growing season.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Summit County, UT (Zone 5b) Very short season
94 days
Last Spring Frost June 10
94 growing days
First Fall Frost September 12
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Summit County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.3

Drainage

Well Drained

Bachelor's Button Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 18 Transplant: May 30 🌸 Bloom: Aug 1 – Oct 17
Recommended (50%) ✗ May not fit
Start indoors: Apr 29 Transplant: Jun 10 🌸 Bloom: Aug 12 – Oct 28
Safe Start (90%) ✗ May not fit
Start indoors: May 10 Transplant: Jun 21 🌸 Bloom: Aug 23 – Nov 8

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 Summit County

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

Soil pH

Your soil pH (6.4–8.3) overlaps with Bachelor's Button's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Bachelor's Button.

How to Plant Bachelor's Button

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

Bachelor's Button Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 2.9" 0" ❄️ Dormant
Jun 2.2" 1.8" 0.4" 💧 Light watering
Jul 2.2" 1.9" 0.3" 💧 Light watering
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 2" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Summit 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 ~1,088 GDD — county provides 1,363 GDD Good fit

Bachelor's Button Planting Timeline — Summit County, UT

Bachelor's Button Planting Calendar

Activity When Date Range
Start Indoors April 29 Apr 29 – May 13
Transplant Outdoors June 10 Jun 10 – Jun 24
Direct Sow May 20 May 20 – Jun 10
Bloom August 12 Aug 12 – Oct 28

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors Direct Sow
June Transplant Outdoors Direct Sow
July
August Bloom
September Bloom
October Bloom
November
December
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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 5b

📆 Growing Season

94 days in Summit County

Growing Tips for Bachelor's Button in Summit County

Direct sow Bachelor's Button outdoors after June 10 in Summit County when soil has warmed and frost danger has passed.

Your 94.0-day growing season in Summit 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.

Summit County receives only 25" 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 Summit County, UT?

Summit County is in Zone 5b with an average last frost of June 10. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Summit County, UT?

Summit County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is June 10 and first fall frost is September 12.

🌱

Your Summit County Garden Planner — Free

A 22-page printable planner built for Summit 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 Summit County, UT. 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.