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When to Plant Zinnia in Uvalde County, TX

Uvalde County, Texas Zone 9a June

Your June game plan for Uvalde County, Texas

We've pulled the most time-sensitive tasks for Uvalde County, Texas this June and put them front and centre. Tackle them in order.

Avg. last frost March 8
Avg. first frost November 14
Soil temp (4") 75°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Bring in the zinnia

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

Get ahead of July
  • First harvests: zinnia

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Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Uvalde County, Texas is in USDA Zone 9a. The average last spring frost is March 8 and the first fall frost is November 14, giving you a growing season of approximately 251 days.

At an elevation of 2,809 feet, Uvalde County receives approximately 59.3 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Zinnia may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Zinnia root diseases.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Uvalde County, TX (Zone 9a) Long season
251 days
Last Spring Frost March 8
251 growing days
First Fall Frost November 14

Uvalde County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Feb 1 Transplant: Feb 8 🌸 Bloom: Apr 19 – Oct 4
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Feb 8 Transplant: Feb 15 🌸 Bloom: Apr 26 – Oct 11
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Mar 16 Transplant: Mar 23 🌸 Bloom: Jun 1 – Nov 16

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 Uvalde County

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

Soil pH

Your soil pH (6.8–7.6) overlaps with Zinnia's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Zinnia.

How to Plant Zinnia

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

Succession Planting Zinnia

4
successive plantings in your 251-day season

Sow every 6.9 weeks. Last sowing by Sep 05 to harvest before frost.

Zinnia 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 Zinnia

Zinnia 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 Zinnia Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.2" 3.7" 0" ✅ Rainfall sufficient
Apr 2.2" 6.3" 0" ✅ Rainfall sufficient
May 2.2" 9.4" 0" ✅ Rainfall sufficient
Jun 2.2" 8.3" 0" ✅ Rainfall sufficient
Jul 2.2" 8.2" 0" ✅ Rainfall sufficient
Aug 2.2" 6.9" 0" ✅ Rainfall sufficient
Sep 2.2" 5.8" 0" ✅ Rainfall sufficient
Oct 2.2" 4.1" 0" ✅ Rainfall sufficient
Nov 2.2" 1.8" 0.4" 💧 Light watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Uvalde County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Zinnia 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.

Zinnia needs ~1,381 GDD — county provides 5,333 GDD Excellent fit

Zinnia Planting Timeline — Uvalde County, TX

Zinnia Planting Calendar

Activity When Date Range
Start Indoors February 8 Feb 8 – Feb 22
Transplant Outdoors February 15 Feb 15 – Mar 1
Direct Sow February 15 Feb 15 – Mar 8
Bloom April 26 Apr 26 – Oct 11

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 Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

251 days in Uvalde County

Growing Tips for Zinnia in Uvalde County

Direct sow Zinnia outdoors after March 08 in Uvalde County when soil has warmed and frost danger has passed.

Common pests for Zinnia 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 when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Uvalde County, TX?

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

What planting zone is Uvalde County, TX?

Uvalde County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 8 and first fall frost is November 14.

🌱

Your Uvalde County Garden Planner — Free

A 22-page printable planner built for Uvalde County (Zone 9a). 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 Uvalde 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.