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When to Plant Cosmos in Freestone County, TX

Freestone County, Texas Zone 8b June

This month in Freestone County, Texas

Welcome to June in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 11
Avg. first frost November 13
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Pick cosmos

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

A few tasks this June that'll pay off in July
  • First harvests: cosmos

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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.

Freestone County, Texas is in USDA Zone 8b. The average last spring frost is March 11 and the first fall frost is November 13, giving you a growing season of approximately 247 days.

At an elevation of 398 feet, Freestone County receives approximately 71.4 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Cosmos during the growing season. Clay soil retains moisture well for Cosmos, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Freestone County, TX (Zone 8b) Long season
247 days
Last Spring Frost March 11
247 growing days
First Fall Frost November 13
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Freestone County Soil Profile

Soil Type

Clay

Soil pH

6.9-7.9

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Feb 6 Transplant: Feb 13 🌸 Bloom: Apr 24 – Sep 25
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Feb 11 Transplant: Feb 18 🌸 Bloom: Apr 29 – Sep 30
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Mar 6 Transplant: Mar 13 🌸 Bloom: May 22 – Oct 23

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 Freestone County

How your county's soil matches Cosmos's growing requirements.

Soil pH

Your soil pH (6.9–7.9) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

Heavy clay soil (46% clay) in Freestone County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Cosmos.

How to Plant Cosmos

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Cosmos

4
successive plantings in your 247-day season

Sow every 6.9 weeks. Last sowing by Aug 15 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Cosmos

Cosmos 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 Cosmos Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 2.2" 4.8" 0" ✅ Rainfall sufficient
Apr 2.2" 7" 0" ✅ Rainfall sufficient
May 2.2" 12.2" 0" ✅ Rainfall sufficient
Jun 2.2" 10.3" 0" ✅ Rainfall sufficient
Jul 2.2" 8.2" 0" ✅ Rainfall sufficient
Aug 2.2" 9.1" 0" ✅ Rainfall sufficient
Sep 2.2" 6.1" 0" ✅ Rainfall sufficient
Oct 2.2" 5" 0" ✅ Rainfall sufficient
Nov 2.2" 2.3" 0" ✅ Rainfall sufficient
Dec 1.9" 0" ❄️ Dormant

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

Cosmos 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.

Cosmos needs ~1,481 GDD — county provides 4,878 GDD Excellent fit

Cosmos Planting Timeline — Freestone County, TX

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors February 18 Feb 18 – Mar 4
Direct Sow February 18 Feb 18 – Mar 11
Bloom April 29 Apr 29 – Sep 30

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
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 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

247 days in Freestone County

Growing Tips for Cosmos in Freestone County

Direct sow Cosmos outdoors after March 11 in Freestone County when soil has warmed and frost danger has passed.

With Freestone County's clay soil (46% clay), work in 3-4 inches of compost before planting Cosmos. Avoid tilling when soil is wet to prevent compaction.

Common pests for Cosmos in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Freestone County, TX?

Freestone County is in Zone 8b with an average last frost of March 11. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Freestone County, TX?

Freestone County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 11 and first fall frost is November 13.

🌱

Your Freestone County Garden Planner — Free

A 22-page printable planner built for Freestone 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 Freestone 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.