When to plant Bachelor's Button in Benton County, MN
For Benton County, gardeners: plant Bachelor's Button April 18 through May 9 once soil reads 50°F.
When to Plant Bachelor's Button in Benton County, MN
June to-do list for Benton County, Minnesota
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Benton County, Minnesota.
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.
Benton County, Minnesota is in USDA Zone 4a. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.
At an elevation of 1,178 feet, Benton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Bachelor's Button to ensure they mature before fall.
Benton County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7
Drainage
Well Drained
Bachelor's Button Planting Risk Windows
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 Benton County
How your county's soil matches Bachelor's Button's growing requirements.
Soil pH
Your soil pH (6.0–7.0) is within Bachelor's Button's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Benton 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 excellent (4.9%) — Bachelor's Button will thrive.
How to Plant Bachelor's Button
Succession Planting Bachelor's Button
Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.
Bachelor's Button Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 3" | 0" | ❄️ Dormant |
| Apr | — | 3.4" | 0" | ❄️ Dormant |
| May | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Benton 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 Planting Timeline — Benton County, MN
Bachelor's Button Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | April 18 | Apr 18 – May 9 |
| Bloom | July 4 | Jul 4 – Sep 5 |
Plant 0.3" deep · 12" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | 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 · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 4a
📆 Growing Season
157 days in Benton County
Growing Tips for Bachelor's Button in Benton County
Direct sow Bachelor's Button outdoors after May 02 in Benton 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.
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 →
Bachelor's Button in Other Locations
Frequently Asked Questions
When should I plant Bachelor's Button in Benton County, MN?
Benton County is in Zone 4a with an average last frost of May 2. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.
What planting zone is Benton County, MN?
Benton County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 2 and first fall frost is October 6.
When should I plant Bachelor's Button in Benton County, MN?
In Benton County, MN, plant Bachelor's Button after the last frost (around May 2) and before the first frost (around October 6). Best results when soil holds above 50°F.
What growing zone is Benton County, MN for Bachelor's Button?
Benton County sits in USDA Zone 4a. Bachelor's Button grows reliably in zones 2a through 11b, so it's a good fit here.
Can Bachelor's Button grow in Benton County's climate?
Yes — Bachelor's Button grows well in Benton County's temperate climate. Benton County averages a 157-day frost-free season, with last frost around May 2 and first frost around October 6.
Your Benton County Garden Planner — Free
A 22-page printable planner built for Benton County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.