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When to Plant Zinnia in Lee County, TX

Lee County, Texas Zone 9a July

July to-do list for Lee County, Texas

Welcome to July in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 28
Avg. first frost November 30
Soil temp (4") 90°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. It's harvest week for zinnia

    If you can't use it all right away, check the food-preservation section of your planner.

Get ahead of August
  • 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.

Lee County, Texas is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 30, giving you a growing season of approximately 275 days.

At an elevation of 1,174 feet, Lee County receives approximately 59.1 inches of rainfall annually with predominantly clay soil. Summer highs average 97°F, so Zinnia may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Zinnia, but amend with compost to improve drainage and prevent root rot. 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
Lee County, TX (Zone 9a) Year-round
275 days
Last Spring Frost February 28
275 growing days
First Fall Frost November 30

Lee County Soil Profile

Soil Type

Clay

Soil pH

7.1-8.2

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Start indoors: Jan 17 Transplant: Jan 24 🌸 Bloom: Apr 4 – Sep 19
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Jan 31 Transplant: Feb 7 🌸 Bloom: Apr 18 – Oct 3
Safe Start (90%) ✓ Fits season (51 days to spare)
Start indoors: Feb 24 Transplant: Mar 3 🌸 Bloom: May 12 – Oct 27

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 Lee County

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

Soil pH

Your soil pH (7.1–8.2) is more alkaline than Zinnia prefers (5.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Lee County is workable for Zinnia. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (2.7%). 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 275-day season

Sow every 6.9 weeks. Last sowing by Sep 21 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 1.6" 0" ❄️ Dormant
Feb 2.2" 1.8" 0.4" 💧 Light watering
Mar 2.2" 4.3" 0" ✅ Rainfall sufficient
Apr 2.2" 5.8" 0" ✅ Rainfall sufficient
May 2.2" 8.6" 0" ✅ Rainfall sufficient
Jun 2.2" 9.5" 0" ✅ Rainfall sufficient
Jul 2.2" 8.1" 0" ✅ Rainfall sufficient
Aug 2.2" 7.3" 0" ✅ Rainfall sufficient
Sep 2.2" 5.2" 0" ✅ Rainfall sufficient
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 2.2" 1.8" 0.4" 💧 Light watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Lee 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 ~1,479 GDD — county provides 6,279 GDD Excellent fit

Zinnia Planting Timeline — Lee County, TX

Zinnia Planting Calendar

Activity When Date Range
Start Indoors January 31 Jan 31 – Feb 14
Transplant Outdoors February 7 Feb 7 – Feb 21
Direct Sow February 7 Feb 7 – Feb 28
Bloom April 18 Apr 18 – Oct 3

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: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

275 days in Lee County

Growing Tips for Zinnia in Lee County

Direct sow Zinnia outdoors after February 28 in Lee County when soil has warmed and frost danger has passed.

With Lee County's clay soil (37% clay), work in 3-4 inches of compost before planting Zinnia. Avoid tilling when soil is wet to prevent compaction.

With summer highs reaching 97°F in Lee County, provide afternoon shade for Zinnia and water deeply in the morning.

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 Lee County, TX?

Lee County is in Zone 9a with an average last frost of February 28. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lee County, TX?

Lee County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 30.

🌱

Your Lee County Garden Planner — Free

A 22-page printable planner built for Lee 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 Lee County, TX. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.