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When to Plant Cosmos in Anderson County, TX

Anderson County, Texas Zone 8b July

July to-do list for Anderson County, Texas

Your garden in Anderson County, Texas is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost March 6
Avg. first frost November 16
Soil temp (4") 89°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Collect cosmos at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Before August arrives, get these ready
  • 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.

Anderson County, Texas is in USDA Zone 8b. The average last spring frost is March 6 and the first fall frost is November 16, giving you a growing season of approximately 255 days.

At an elevation of 86 feet, Anderson County receives approximately 73.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Cosmos may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Cosmos will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Anderson County, TX (Zone 8b) Long season
255 days
Last Spring Frost March 6
255 growing days
First Fall Frost November 16

Anderson County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (55 days to spare)
Start indoors: Jan 30 Transplant: Feb 6 🌸 Bloom: Apr 17 – Sep 18
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Feb 6 Transplant: Feb 13 🌸 Bloom: Apr 24 – Sep 25
Safe Start (90%) ✓ Fits season (51 days to spare)
Start indoors: Feb 24 Transplant: Mar 3 🌸 Bloom: May 12 – Oct 13

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 Anderson County

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Cosmos's range (6.0–8.0), though not a perfect match.

Soil Texture

Sandy soil in Anderson County warms quickly in spring but drains fast. Cosmos will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Cosmos.

How to Plant Cosmos

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

Succession Planting Cosmos

5
successive plantings in your 255-day season

Sow every 6.9 weeks. Last sowing by Aug 18 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 2.9" 0" ❄️ Dormant
Mar 2.2" 4.1" 0" ✅ Rainfall sufficient
Apr 2.2" 7.9" 0" ✅ Rainfall sufficient
May 2.2" 11.5" 0" ✅ Rainfall sufficient
Jun 2.2" 11.3" 0" ✅ Rainfall sufficient
Jul 2.2" 8.8" 0" ✅ Rainfall sufficient
Aug 2.2" 10" 0" ✅ Rainfall sufficient
Sep 2.2" 6.1" 0" ✅ Rainfall sufficient
Oct 2.2" 4.9" 0" ✅ Rainfall sufficient
Nov 2.2" 2.4" 0" ✅ Rainfall sufficient
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Anderson 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 ~1,650 GDD — county provides 5,610 GDD Excellent fit

Cosmos Planting Timeline — Anderson County, TX

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow February 13 Feb 13 – Mar 6
Bloom April 24 Apr 24 – Sep 25

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March Direct Sow
April Bloom
May Bloom
June Bloom
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 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

255 days in Anderson County

Growing Tips for Cosmos in Anderson County

Direct sow Cosmos outdoors after March 06 in Anderson County when soil has warmed and frost danger has passed.

Sandy soil in Anderson County dries quickly — mulch Cosmos with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Anderson County, provide afternoon shade for Cosmos and water deeply in the morning.

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 Anderson County, TX?

Anderson County is in Zone 8b with an average last frost of March 6. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Anderson County, TX?

Anderson County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 6 and first fall frost is November 16.

🌱

Your Anderson County Garden Planner — Free

A 22-page printable planner built for Anderson 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 Anderson County, TX. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.