Blog

When to Plant Marigolds in Erath County, TX

Erath County, Texas Zone 8b May

Erath County, Texas gardeners: here's your May plan

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 25
Avg. first frost November 11
Soil temp (4") 64°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. Basket week: marigolds

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Looking ahead to June
  • First harvests: marigolds

Instant PDF download. No spam, unsubscribe any time.

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.

Erath County, Texas is in USDA Zone 8b. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.

At an elevation of 1,968 feet, Erath County receives approximately 55.9 inches of rainfall annually with predominantly clay soil. Summer highs average 92°F, providing good warmth for Marigolds during the growing season. Clay soil retains moisture well for Marigolds, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Marigolds root diseases.

Erath County, TX (Zone 8b) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11

Erath County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Apr 20 Transplant: Mar 2 🍅 Harvest: Apr 27 – Sep 14
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Apr 29 Transplant: Mar 11 🍅 Harvest: May 6 – Sep 23
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: May 20 Transplant: Apr 1 🍅 Harvest: May 27 – Oct 14

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 Erath County

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

Soil pH

Your soil pH (7.3–7.7) overlaps with Marigolds's range (6.0–7.5), though not a perfect match.

Soil Texture

Heavy clay soil (46% clay) in Erath County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Marigolds.

How to Plant Marigolds

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

Succession Planting Marigolds

5
successive plantings in your 231-day season

Sow every 5.7 weeks. Last sowing by Sep 02 to harvest before frost.

Plant 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 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 2.1" 0" ❄️ Dormant
Mar 2.2" 3.2" 0" ✅ Rainfall sufficient
Apr 2.2" 5.8" 0" ✅ Rainfall sufficient
May 2.2" 7.2" 0" ✅ Rainfall sufficient
Jun 2.2" 8.1" 0" ✅ Rainfall sufficient
Jul 2.2" 8.1" 0" ✅ Rainfall sufficient
Aug 2.2" 6.7" 0" ✅ Rainfall sufficient
Sep 2.2" 5.9" 0" ✅ Rainfall sufficient
Oct 2.2" 4" 0" ✅ Rainfall sufficient
Nov 2.2" 2" 0.2" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Erath 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 ~1,140 GDD — county provides 4,389 GDD Excellent fit

Marigolds Planting Timeline — Erath County, TX

Marigolds Planting Calendar

Activity When Date Range
Start Indoors April 29 Apr 29 – May 13
Transplant Outdoors March 11 Mar 11 – Mar 25
Direct Sow March 11 Mar 11 – Apr 1
Harvest May 6 May 6 – Sep 23

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8b

📆 Growing Season

231 days in Erath County

Growing Tips for Marigolds in Erath County

Direct sow Marigolds outdoors after March 25 in Erath County when soil has warmed and frost danger has passed.

With Erath County's clay soil (46% clay), work in 3-4 inches of compost before planting Marigolds. Avoid tilling when soil is wet to prevent compaction.

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

With 56" of annual rainfall in Erath 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 Erath County, TX?

Erath County is in Zone 8b with an average last frost of March 25. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Erath County, TX?

Erath County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 25 and first fall frost is November 11.

🌱

Your Erath County Garden Planner — Free

A 24-page printable planner built for Erath County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Erath 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.