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When to Plant Zinnia in Lavaca County, TX

Lavaca County, Texas Zone 9a June

June to-do list for Lavaca 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 February 26
Avg. first frost December 1
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Collect zinnia at their peak

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

Before July arrives, get these ready
  • 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.

Lavaca County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is December 1, giving you a growing season of approximately 278 days.

At an elevation of 254 feet, Lavaca County receives approximately 60.4 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Zinnia during the growing season. 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
Lavaca County, TX (Zone 9a) Year-round
278 days
Last Spring Frost February 26
278 growing days
First Fall Frost December 1

Lavaca County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Jan 15 Transplant: Jan 22 🌸 Bloom: Apr 2 – Sep 17
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Jan 29 Transplant: Feb 5 🌸 Bloom: Apr 16 – Oct 1
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: Feb 21 Transplant: Feb 28 🌸 Bloom: May 9 – Oct 24

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 Lavaca County

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

Soil pH

Your soil pH (6.2–7.8) overlaps with Zinnia's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Zinnia.

Organic Matter

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

How to Plant Zinnia

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

Succession Planting Zinnia

5
successive plantings in your 278-day season

Sow every 6.9 weeks. Last sowing by Sep 22 to harvest before frost.

Zinnia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.4" 0" ❄️ Dormant
Feb 2.2" 1.9" 0.3" 💧 Light watering
Mar 2.2" 3.5" 0" ✅ Rainfall sufficient
Apr 2.2" 5.9" 0" ✅ Rainfall sufficient
May 2.2" 8.6" 0" ✅ Rainfall sufficient
Jun 2.2" 10.9" 0" ✅ Rainfall sufficient
Jul 2.2" 7.4" 0" ✅ Rainfall sufficient
Aug 2.2" 7.7" 0" ✅ Rainfall sufficient
Sep 2.2" 5.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.7" 0" ✅ Rainfall sufficient
Nov 2.2" 2.4" 0" ✅ Rainfall sufficient
Dec 2.2" 1.9" 0.3" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Lavaca 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 ~1,332 GDD — county provides 5,719 GDD Excellent fit

Zinnia Planting Timeline — Lavaca County, TX

Zinnia Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors February 5 Feb 5 – Feb 19
Direct Sow February 5 Feb 5 – Feb 26
Bloom April 16 Apr 16 – Oct 1

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors Transplant Outdoors Direct Sow
March
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

278 days in Lavaca County

Growing Tips for Zinnia in Lavaca County

Direct sow Zinnia outdoors after February 26 in Lavaca 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 Lavaca County, TX?

Lavaca County is in Zone 9a with an average last frost of February 26. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lavaca County, TX?

Lavaca County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is December 1.

🌱

Your Lavaca County Garden Planner — Free

A 22-page printable planner built for Lavaca 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 Lavaca 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.