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When to Plant Marigolds in McMullen County, TX

McMullen County, Texas Zone 9b August

Top priorities for McMullen County, Texas gardeners in August

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

Avg. last frost February 20
Avg. first frost December 1
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 13 hrs
  1. Harvest marigolds as they ripen

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

Get ahead of September
  • First harvests: marigolds

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Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

McMullen County, Texas is in USDA Zone 9b. The average last spring frost is February 20 and the first fall frost is December 1, giving you a growing season of approximately 284 days.

At an elevation of 3,741 feet, McMullen County receives approximately 58 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Marigolds may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Marigolds root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
McMullen County, TX (Zone 9b) Year-round
284 days
Last Spring Frost February 20
284 growing days
First Fall Frost December 1

McMullen County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Marigolds Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Dec 30 Transplant: Jan 13 🌸 Bloom: Mar 10 – Sep 1
Recommended (50%) ✓ Fits season (74 days to spare)
Start indoors: Jan 16 Transplant: Jan 30 🌸 Bloom: Mar 27 – Sep 18
Safe Start (90%) ✓ Fits season (67 days to spare)
Start indoors: Feb 10 Transplant: Feb 24 🌸 Bloom: Apr 21 – Oct 13

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 McMullen County

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

Soil pH

Your soil pH (6.8–7.2) is within Marigolds's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

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

How to Plant Marigolds

0.3"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Marigolds

6
successive plantings in your 284-day season

Sow every 5.7 weeks. Last sowing by Sep 22 to harvest before frost.

Marigolds Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 Marigolds

Marigolds 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 Marigolds Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 2.2" 2" 0.2" 💧 Light watering
Mar 2.2" 3.7" 0" ✅ Rainfall sufficient
Apr 2.2" 6.4" 0" ✅ Rainfall sufficient
May 2.2" 9.4" 0" ✅ Rainfall sufficient
Jun 2.2" 9.8" 0" ✅ Rainfall sufficient
Jul 2.2" 7.3" 0" ✅ Rainfall sufficient
Aug 2.2" 6.5" 0" ✅ Rainfall sufficient
Sep 2.2" 4.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 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 McMullen County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Marigolds 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.

Marigolds needs ~1,635 GDD — county provides 7,766 GDD Excellent fit

Marigolds Planting Timeline — McMullen County, TX

Marigolds Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors January 30 Jan 30 – Feb 13
Direct Sow January 30 Jan 30 – Feb 20
Bloom March 27 Mar 27 – Sep 18

Plant 0.3" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

284 days in McMullen County

Growing Tips for Marigolds in McMullen County

Direct sow Marigolds outdoors after February 20 in McMullen County when soil has warmed and frost danger has passed.

With summer highs reaching 103°F in McMullen County, provide afternoon shade for Marigolds and water deeply in the morning.

Common pests for Marigolds in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

With 58" of annual rainfall in McMullen County, ensure good drainage for Marigolds — excess moisture can promote root rot and fungal diseases.

General growing tips

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Cabbage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Marigolds Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower heads dry on plant. Pull dried petals to reveal seeds.
Storage Store in envelopes; viable 3 years at 35°F, under 50% humidity.

Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.

Frequently Asked Questions

When should I plant Marigolds in McMullen County, TX?

McMullen County is in Zone 9b with an average last frost of February 20. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is McMullen County, TX?

McMullen County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 20 and first fall frost is December 1.

🌱

Your McMullen County Garden Planner — Free

A 22-page printable planner built for McMullen County (Zone 9b). 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 McMullen County, TX. Local conditions may vary. Last updated: August 2026.

Sources & credits

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