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When to Plant Cosmos in Upshur County, TX

Upshur County, Texas Zone 8b June

June in Upshur County, Texas — your action list

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

Avg. last frost March 9
Avg. first frost November 17
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Pick cosmos

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

Get ahead of 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.

Upshur County, Texas is in USDA Zone 8b. The average last spring frost is March 9 and the first fall frost is November 17, giving you a growing season of approximately 253 days.

At an elevation of 51 feet, Upshur County receives approximately 74 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°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
Upshur County, TX (Zone 8b) Long season
253 days
Last Spring Frost March 9
253 growing days
First Fall Frost November 17

Upshur County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.6-6.4

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (55 days to spare)
Start indoors: Jan 31 Transplant: Feb 7 🌸 Bloom: Apr 18 – Sep 19
Recommended (50%) ✓ Fits season (50 days to spare)
Start indoors: Feb 9 Transplant: Feb 16 🌸 Bloom: Apr 27 – Sep 28
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Mar 1 Transplant: Mar 8 🌸 Bloom: May 17 – Oct 18

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 Upshur County

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

Soil pH

Your soil pH (5.6–6.4) overlaps with Cosmos's range (6.0–8.0), though not a perfect match.

Soil Texture

Sandy soil in Upshur 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 253-day season

Sow every 6.9 weeks. Last sowing by Aug 19 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
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 2.1" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.2" 5.3" 0" ✅ Rainfall sufficient
Apr 2.2" 7.9" 0" ✅ Rainfall sufficient
May 2.2" 10.3" 0" ✅ Rainfall sufficient
Jun 2.2" 10.4" 0" ✅ Rainfall sufficient
Jul 2.2" 11.1" 0" ✅ Rainfall sufficient
Aug 2.2" 8.5" 0" ✅ Rainfall sufficient
Sep 2.2" 6.3" 0" ✅ Rainfall sufficient
Oct 2.2" 5" 0" ✅ Rainfall sufficient
Nov 2.2" 2.4" 0" ✅ Rainfall sufficient
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Upshur 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 ~1,594 GDD — county provides 5,376 GDD Excellent fit

Cosmos Planting Timeline — Upshur County, TX

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 9 Feb 9 – Feb 23
Transplant Outdoors February 16 Feb 16 – Mar 2
Direct Sow February 16 Feb 16 – Mar 9
Bloom April 27 Apr 27 – Sep 28

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

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

253 days in Upshur County

Growing Tips for Cosmos in Upshur County

Direct sow Cosmos outdoors after March 09 in Upshur County when soil has warmed and frost danger has passed.

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

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 Upshur County, TX?

Upshur County is in Zone 8b with an average last frost of March 9. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Upshur County, TX?

Upshur County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 9 and first fall frost is November 17.

🌱

Your Upshur County Garden Planner — Free

A 22-page printable planner built for Upshur 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 Upshur 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.