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When to Plant Cosmos in Wise County, TX

Wise County, Texas Zone 8a June

Wise County, Texas gardeners: here's your June plan

A quick June briefing for Wise County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 25
Avg. first frost November 11
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Start harvesting cosmos

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

July will be here before you know it — start on
  • 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.

Wise County, Texas is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.

At an elevation of 3,288 feet, Wise County receives approximately 53.8 inches of rainfall annually with predominantly clay soil. Summer highs average 92°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
Wise County, TX (Zone 8a) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11

Wise County Soil Profile

Soil Type

Clay

Soil pH

6.8-7.8

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (38 days to spare)
Start indoors: Feb 14 Transplant: Feb 28 🌸 Bloom: May 9 – Sep 26
Recommended (50%) ✓ Fits season (35 days to spare)
Start indoors: Feb 25 Transplant: Mar 11 🌸 Bloom: May 20 – Oct 7
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Mar 18 Transplant: Apr 1 🌸 Bloom: Jun 10 – Oct 28

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 Wise County

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

Soil pH

Your soil pH (6.8–7.8) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

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

Drainage

Cosmos prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (2.9%). 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 231-day season

Sow every 6.9 weeks. Last sowing by Aug 13 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 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 1.3" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 2.2" 3.3" 0" ✅ Rainfall sufficient
Apr 2.2" 6.7" 0" ✅ Rainfall sufficient
May 2.2" 8.8" 0" ✅ Rainfall sufficient
Jun 2.2" 7.9" 0" ✅ Rainfall sufficient
Jul 2.2" 6.5" 0" ✅ Rainfall sufficient
Aug 2.2" 5.8" 0" ✅ Rainfall sufficient
Sep 2.2" 4.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.7" 0" ✅ Rainfall sufficient
Nov 2.2" 1.6" 0.6" 💧 Light watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Wise 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 ~1,425 GDD — county provides 4,389 GDD Excellent fit

Cosmos Planting Timeline — Wise County, TX

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors March 11 Mar 11 – Mar 25
Direct Sow March 11 Mar 11 – Apr 1
Bloom May 20 May 20 – Oct 7

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 Direct Sow
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
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: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

231 days in Wise County

Growing Tips for Cosmos in Wise County

Direct sow Cosmos outdoors after March 25 in Wise County when soil has warmed and frost danger has passed.

With Wise 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 Wise County, TX?

Wise County is in Zone 8a with an average last frost of March 25. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wise County, TX?

Wise County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 11.

🌱

Your Wise County Garden Planner — Free

A 22-page printable planner built for Wise 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 Wise 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.