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When to Plant Marigolds in Bexar County, TX

Bexar County, Texas Zone 9a May

Your May game plan for Bexar County, Texas

Each item below is timed to Bexar County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 11
Avg. first frost November 17
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Pick marigolds

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

Coming up in June — start thinking about
  • 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.

Bexar County, Texas is in USDA Zone 9a. The average last spring frost is March 11 and the first fall frost is November 17, giving you a growing season of approximately 251 days.

At an elevation of 3,197 feet, Bexar County receives approximately 52.1 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Marigolds during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Marigolds root diseases.

Bexar County, TX (Zone 9a) Long season
251 days
Last Spring Frost March 11
251 growing days
First Fall Frost November 17
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Bexar County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Apr 5 Transplant: Feb 15 🍅 Harvest: Apr 12 – Sep 13
Recommended (50%) ✓ Fits season (55 days to spare)
Start indoors: Apr 15 Transplant: Feb 25 🍅 Harvest: Apr 22 – Sep 23
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: May 12 Transplant: Mar 24 🍅 Harvest: May 19 – 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 Bexar County

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

Soil pH

Your soil pH (6.5–7.8) overlaps with Marigolds's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). 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 251-day season

Sow every 5.7 weeks. Last sowing by Sep 08 to harvest before frost.

Plant 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 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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.2" 3.6" 0" ✅ Rainfall sufficient
Apr 2.2" 5.6" 0" ✅ Rainfall sufficient
May 2.2" 7.5" 0" ✅ Rainfall sufficient
Jun 2.2" 8.2" 0" ✅ Rainfall sufficient
Jul 2.2" 6.3" 0" ✅ Rainfall sufficient
Aug 2.2" 6.3" 0" ✅ Rainfall sufficient
Sep 2.2" 4.9" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 0" ✅ Rainfall sufficient
Nov 2.2" 1.9" 0.3" 💧 Light watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Bexar 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 ~1,185 GDD — county provides 4,957 GDD Excellent fit

Marigolds Planting Timeline — Bexar County, TX

Marigolds Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors February 25 Feb 25 – Mar 11
Direct Sow February 25 Feb 25 – Mar 18
Harvest April 22 Apr 22 – Sep 23

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9a

📆 Growing Season

251 days in Bexar County

Growing Tips for Marigolds in Bexar County

Direct sow Marigolds outdoors after March 11 in Bexar County when soil has warmed and frost danger has passed.

Common pests for Marigolds 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 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 Bexar County, TX?

Bexar County is in Zone 9a with an average last frost of March 11. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bexar County, TX?

Bexar County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 11 and first fall frost is November 17.

🌱

Your Bexar County Garden Planner — Free

A 24-page printable planner built for Bexar 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 Bexar County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

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