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When to Plant Bachelor's Button in Hamilton County, TX

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.

Hamilton County, Texas is in USDA Zone 8b. The average last spring frost is March 18 and the first fall frost is November 12, giving you a growing season of approximately 239 days.

At an elevation of 4,378 feet, Hamilton County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Bachelor's Button during the growing season. Clay soil retains moisture well for Bachelor's Button, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Bachelor's Button root diseases.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Hamilton County, TX (Zone 8b) Long season
239 days
Last Spring Frost March 18
239 growing days
First Fall Frost November 12

Hamilton County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.2

Drainage

Well Drained

Monthly Watering Guide for Bachelor's Button

Bachelor's Button needs approximately 1 inches of water per week (4.3" 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 2.2" 0" ❄️ Dormant
Mar 4.3" 3.8" 0.5" 💧 Light watering
Apr 4.3" 6.9" 0" ✅ Rainfall sufficient
May 4.3" 9.7" 0" ✅ Rainfall sufficient
Jun 4.3" 10.8" 0" ✅ Rainfall sufficient
Jul 4.3" 8.7" 0" ✅ Rainfall sufficient
Aug 4.3" 8.5" 0" ✅ Rainfall sufficient
Sep 4.3" 5.7" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 1.6" 0" ❄️ Dormant

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

Bachelor's Button Planting Timeline — Hamilton County, TX

Bachelor's Button Planting Calendar

Activity When Date Range
Transplant Outdoors February 25 Feb 25 – Mar 11
Direct Sow January 28 Jan 28 – Feb 18
Bloom April 29 Apr 29 – Aug 26
Fall Sowing September 17 Sep 17 – Oct 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 8b

📆 Growing Season

239 days in Hamilton County

Growing Tips for Hamilton County

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 Hamilton County, TX?

Hamilton County is in Zone 8b with an average last frost of March 18. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, TX?

Hamilton County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 18 and first fall frost is November 12.

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Your Hamilton County Garden Planner — Free

A 22-page printable planner built for Hamilton County (Zone 8b). 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 Hamilton County, TX. 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.