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When to plant Gaillardia (Blanket Flower) in Williamson County, IL

Plant Gaillardia (Blanket Flower) in Williamson County after April 10; the prime window is April 17–May 8.

When to Plant Gaillardia (Blanket Flower) in Williamson County, IL

Williamson County, Illinois Zone 7a August

Your August gardening checklist

Your garden in Williamson County, Illinois is working on a schedule, even when you're not. Here's where you should be this August.

Avg. last frost April 10
Avg. first frost October 20
Soil temp (4") 81°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for gaillardia (blanket flower)

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Get ahead of September
  • First harvests: gaillardia (blanket flower)

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Gaillardia (Gaillardia aristata), the native blanket flower of the American West, is one of the most floriferous and longest-blooming perennials available — producing cheerful, daisy-like flowers in fiery red, orange, and yellow combinations from early summer through hard frost in most climates. Named for the way its spreading colonies mimic the patterned blankets of Indigenous American weavers, gaillardia thrives in the exact conditions that challenge other perennials: poor, dry, gravelly soil in full sun. An outstanding pollinator plant, attracting bees, butterflies, and finches that feed on its seed heads. Somewhat short-lived (3–5 years) but self-seeds freely to sustain garden colonies.

Williamson County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 20, giving you a growing season of approximately 193 days.

At an elevation of 1,253 feet, Williamson County receives approximately 38.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Gaillardia (Blanket Flower) during the growing season.

Perennial Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting
Williamson County, IL (Zone 7a) Moderate season
193 days
Last Spring Frost April 10
193 growing days
First Fall Frost October 20

Williamson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Gaillardia (Blanket Flower) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 15 Transplant: Apr 12 🌸 Bloom: Jun 21 – Nov 8
Recommended (50%) ✗ May not fit
Start indoors: Feb 20 Transplant: Apr 17 🌸 Bloom: Jun 26 – Nov 13
Safe Start (90%) ✗ May not fit
Start indoors: Mar 4 Transplant: Apr 29 🌸 Bloom: Jul 8 – Nov 25

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 Williamson County

How your county's soil matches Gaillardia (Blanket Flower)'s growing requirements.

Soil pH

Your soil pH (6.2–7.2) overlaps with Gaillardia (Blanket Flower)'s range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Williamson County is excellent for Gaillardia (Blanket Flower) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) — Gaillardia (Blanket Flower) will thrive.

How to Plant Gaillardia (Blanket Flower)

0.1"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Gaillardia (Blanket Flower)

3
successive plantings in your 193-day season

Sow every 8 weeks. Last sowing by Jul 12 to harvest before frost.

Gaillardia (Blanket Flower) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 Gaillardia (Blanket Flower)

Gaillardia (Blanket Flower) 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 Gaillardia (Blanket Flower) Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.2" 4" 0" ✅ Rainfall sufficient
May 2.2" 4.9" 0" ✅ Rainfall sufficient
Jun 2.2" 4.8" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.7" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.4" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

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

Gaillardia (Blanket Flower) 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.

Gaillardia (Blanket Flower) needs ~1,551 GDD — county provides 3,522 GDD Excellent fit

Gaillardia (Blanket Flower) Planting Timeline — Williamson County, IL

Gaillardia (Blanket Flower) Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 17 Apr 17 – May 8
Bloom June 26 Jun 26 – Nov 13

Plant 0.1" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

193 days in Williamson County

Growing Tips for Gaillardia (Blanket Flower) in Williamson County

Direct sow Gaillardia (Blanket Flower) outdoors after April 10 in Williamson County when soil has warmed and frost danger has passed.

Common pests for Gaillardia (Blanket Flower) in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6–8 weeks before last frost or direct-sow after last frost. Seeds need light to germinate — press onto soil surface without covering, or cover very lightly (1/8 inch). Transplant after last frost when soil has warmed. Lean, well-drained soil is essential — rich or wet soil causes sprawl and root rot. Deadhead spent blooms to prolong the season, but leave some heads for self-seeding to renew the planting. Divide every 2–3 years in spring to maintain vigor. Drought-tolerant once established; overwatering is more damaging than underwatering. Year 2+ plants deliver the fullest multi-season bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Gaillardia (Blanket Flower) in Williamson County, IL?

Williamson County is in Zone 7a with an average last frost of April 10. Plan your Gaillardia (Blanket Flower) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Williamson County, IL?

Williamson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 20.

When should I plant Gaillardia (Blanket Flower) in Williamson County, IL?

In Williamson County, IL, plant Gaillardia (Blanket Flower) after the last frost (around April 10) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Williamson County, IL for Gaillardia (Blanket Flower)?

Williamson County sits in USDA Zone 7a. Gaillardia (Blanket Flower) grows reliably in zones 3a through 10b, so it's a good fit here.

Can Gaillardia (Blanket Flower) grow in Williamson County's climate?

Yes — Gaillardia (Blanket Flower) grows well in Williamson County's temperate climate. Williamson County averages a 193-day frost-free season, with last frost around April 10 and first frost around October 20.

🌱

Your Williamson County Garden Planner — Free

A 22-page printable planner built for Williamson County (Zone 7a). 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 Williamson County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

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