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When to Plant Cosmos in Fannin County, TX

Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.

Fannin County, Texas is in USDA Zone 8a. The average last spring frost is March 16 and the first fall frost is November 15, giving you a growing season of approximately 244 days.

At an elevation of 282 feet, Fannin County receives approximately 63.8 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Cosmos during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Fannin County, TX (Zone 8a) Long season
244 days
Last Spring Frost March 16
244 growing days
First Fall Frost November 15

Fannin County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Cosmos Planting Timeline — Fannin County, TX

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors March 2 Mar 2 – Mar 16
Direct Sow March 2 Mar 2 – Mar 23
Bloom May 11 May 11 – Sep 28

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 8a

📆 Growing Season

244 days in Fannin County

Growing Tips for Fannin County

Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cosmos in Fannin County, TX?

Fannin County is in Zone 8a with an average last frost of March 16. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fannin County, TX?

Fannin County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 16 and first fall frost is November 15.

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Your Fannin County Garden Planner — Free

A 22-page printable planner built for Fannin County (Zone 8a). 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 Fannin County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

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