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When to Plant Cosmos in Nueces County, TX

Nueces County, Texas Zone 10a June

June in the garden — Nueces County, Texas

Your Nueces County, Texas garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost February 10
Avg. first frost December 10
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 13.7 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.

Coming up in July — start thinking about
  • 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.

Nueces County, Texas is in USDA Zone 10a. The average last spring frost is February 10 and the first fall frost is December 10, giving you a growing season of approximately 303 days.

At an elevation of 1,586 feet, Nueces County receives approximately 53.3 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Cosmos may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Nueces County, TX (Zone 10a) Year-round
303 days
Last Spring Frost February 10
303 growing days
First Fall Frost December 10

Nueces County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (91 days to spare)
Start indoors: Dec 22 Transplant: Dec 8 🌸 Bloom: Feb 16 – Aug 31
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Jan 13 Transplant: Dec 30 🌸 Bloom: Mar 10 – Sep 22
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Feb 10 Transplant: Jan 27 🌸 Bloom: Apr 7 – Oct 20

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 Nueces 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

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Cosmos.

How to Plant Cosmos

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

Succession Planting Cosmos

6
successive plantings in your 303-day season

Sow every 6.9 weeks. Last sowing by Sep 11 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 1.6" 0" ❄️ Dormant
Feb 2.2" 1.6" 0.6" 💧 Light watering
Mar 2.2" 3.6" 0" ✅ Rainfall sufficient
Apr 2.2" 5.4" 0" ✅ Rainfall sufficient
May 2.2" 7.5" 0" ✅ Rainfall sufficient
Jun 2.2" 8.9" 0" ✅ Rainfall sufficient
Jul 2.2" 7.2" 0" ✅ Rainfall sufficient
Aug 2.2" 5.9" 0" ✅ Rainfall sufficient
Sep 2.2" 5.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 2.2" 1.7" 0.5" 💧 Light watering
Dec 2.2" 1.3" 0.9" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Nueces 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 6,460 GDD Excellent fit

Cosmos Planting Timeline — Nueces County, TX

Cosmos Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors December 30 Dec 30 – Jan 13
Direct Sow December 30 Dec 30 – Jan 20
Bloom March 10 Mar 10 – Sep 22

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

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors Direct Sow
February
March Bloom
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December Transplant Outdoors Direct Sow

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 10a

📆 Growing Season

303 days in Nueces County

Growing Tips for Cosmos in Nueces County

Direct sow Cosmos outdoors after February 10 in Nueces 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 Nueces County, TX?

Nueces County is in Zone 10a with an average last frost of February 10. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Nueces County, TX?

Nueces County, Texas is in USDA Hardiness Zone 10a. The average last spring frost is February 10 and first fall frost is December 10.

🌱

Your Nueces County Garden Planner — Free

A 22-page printable planner built for Nueces County (Zone 10a). 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 Nueces 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.