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When to Plant Cosmos in Haskell County, TX

Haskell County, Texas Zone 8a June

Your June planting checklist for Haskell County, Texas

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 26
Avg. first frost November 11
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Pick cosmos

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before July 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.

Haskell County, Texas is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 11, giving you a growing season of approximately 230 days.

At an elevation of 3,062 feet, Haskell County receives approximately 54.8 inches of rainfall annually with predominantly loam soil. Summer highs average 91°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
Haskell County, TX (Zone 8a) Long season
230 days
Last Spring Frost March 26
230 growing days
First Fall Frost November 11
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Haskell County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.5

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Feb 19 Transplant: Mar 5 🌸 Bloom: May 14 – Oct 1
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Feb 26 Transplant: Mar 12 🌸 Bloom: May 21 – Oct 8
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 Haskell County

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

Soil pH

Your soil pH (6.4–7.5) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

The loam soil in Haskell County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Cosmos.

Organic Matter

Organic matter is moderate (2.4%). 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 230-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

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 1.7" 0" ❄️ Dormant
Mar 2.2" 3.1" 0" ✅ Rainfall sufficient
Apr 2.2" 5.2" 0" ✅ Rainfall sufficient
May 2.2" 8.5" 0" ✅ Rainfall sufficient
Jun 2.2" 9.3" 0" ✅ Rainfall sufficient
Jul 2.2" 7" 0" ✅ Rainfall sufficient
Aug 2.2" 7.1" 0" ✅ Rainfall sufficient
Sep 2.2" 4.7" 0" ✅ Rainfall sufficient
Oct 2.2" 3.8" 0" ✅ Rainfall sufficient
Nov 2.2" 1.7" 0.5" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Haskell 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 ~1,369 GDD — county provides 4,197 GDD Excellent fit

Cosmos Planting Timeline — Haskell County, TX

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors March 12 Mar 12 – Mar 26
Direct Sow March 12 Mar 12 – Apr 2
Bloom May 21 May 21 – Oct 8

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
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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 8a

📆 Growing Season

230 days in Haskell County

Growing Tips for Cosmos in Haskell County

Direct sow Cosmos outdoors after March 26 in Haskell County when soil has warmed and frost danger has passed.

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 Haskell County, TX?

Haskell County is in Zone 8a with an average last frost of March 26. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Haskell County, TX?

Haskell County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 11.

🌱

Your Haskell County Garden Planner — Free

A 22-page printable planner built for Haskell 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 Haskell 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.