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When to Plant Marigolds in Somervell County, TX

Somervell County, Texas Zone 8b May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Somervell County, Texas.

Avg. last frost March 19
Avg. first frost November 12
Soil temp (4") 56°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. Basket week: marigolds

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of June
  • 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.

Somervell County, Texas is in USDA Zone 8b. The average last spring frost is March 19 and the first fall frost is November 12, giving you a growing season of approximately 238 days.

At an elevation of 4,773 feet, Somervell County receives approximately 64.7 inches of rainfall annually with predominantly clay soil. Summer highs average 90°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.

Somervell County, TX (Zone 8b) Long season
238 days
Last Spring Frost March 19
238 growing days
First Fall Frost November 12
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Somervell County Soil Profile

Soil Type

Clay

Soil pH

7.2-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Apr 12 Transplant: Feb 22 🍅 Harvest: Apr 19 – Sep 6
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Apr 23 Transplant: Mar 5 🍅 Harvest: Apr 30 – Sep 17
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: May 17 Transplant: Mar 29 🍅 Harvest: May 24 – Oct 11

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 Somervell County

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

Soil pH

Your soil pH (7.2–7.8) overlaps with Marigolds's range (6.0–7.5), though not a perfect match.

Soil Texture

Heavy clay soil (46% clay) in Somervell 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 238-day season

Sow every 5.7 weeks. Last sowing by Sep 03 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/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 1.8" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 2.2" 4.3" 0" ✅ Rainfall sufficient
Apr 2.2" 6.9" 0" ✅ Rainfall sufficient
May 2.2" 10.2" 0" ✅ Rainfall sufficient
Jun 2.2" 10.5" 0" ✅ Rainfall sufficient
Jul 2.2" 7.5" 0" ✅ Rainfall sufficient
Aug 2.2" 7.8" 0" ✅ Rainfall sufficient
Sep 2.2" 5.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.8" 0" ✅ Rainfall sufficient
Nov 2.2" 2.4" 0" ✅ Rainfall sufficient
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Somervell 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 ~1,050 GDD — county provides 4,165 GDD Excellent fit

Marigolds Planting Timeline — Somervell County, TX

Marigolds Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 – May 7
Transplant Outdoors March 5 Mar 5 – Mar 19
Direct Sow March 5 Mar 5 – Mar 26
Harvest April 30 Apr 30 – Sep 17

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors Direct Sow
April Start Indoors Harvest
May Start Indoors 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 8b

📆 Growing Season

238 days in Somervell County

Growing Tips for Marigolds in Somervell County

Direct sow Marigolds outdoors after March 19 in Somervell County when soil has warmed and frost danger has passed.

With Somervell 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 65" of annual rainfall in Somervell 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 Somervell County, TX?

Somervell County is in Zone 8b with an average last frost of March 19. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Somervell County, TX?

Somervell County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 19 and first fall frost is November 12.

🌱

Your Somervell County Garden Planner — Free

A 24-page printable planner built for Somervell 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.

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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 Somervell 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.