Blog

When to Plant Marigolds in Hidalgo County, TX

Hidalgo County, Texas Zone 10a July

Your July gardening checklist

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

Avg. last frost February 6
Avg. first frost December 18
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for marigolds

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Get ahead of August
  • 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.

Hidalgo County, Texas is in USDA Zone 10a. The average last spring frost is February 6 and the first fall frost is December 18, giving you a growing season of approximately 315 days.

At an elevation of 4,081 feet, Hidalgo County receives approximately 67 inches of rainfall annually with predominantly loam soil. Summer highs average 100°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
Hidalgo County, TX (Zone 10a) Year-round
315 days
Last Spring Frost February 6
315 growing days
First Fall Frost December 18

Hidalgo County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Marigolds Planting Risk Windows

Early Start (70% safe) ✓ Fits season (118 days to spare)
Start indoors: Dec 14 Transplant: Dec 14 🌸 Bloom: Feb 8 – Aug 16
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Jan 2 Transplant: Jan 2 🌸 Bloom: Feb 27 – Sep 4
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Jan 29 Transplant: Jan 29 🌸 Bloom: Mar 26 – Oct 1

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 Hidalgo County

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

Soil pH

Your soil pH (6.2–7.8) overlaps with Marigolds's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Hidalgo 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

7
successive plantings in your 315-day season

Sow every 5.7 weeks. Last sowing by Oct 09 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

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 2.2" 2.1" 0.1" 💧 Light watering
Mar 2.2" 3.6" 0" ✅ Rainfall sufficient
Apr 2.2" 6.7" 0" ✅ Rainfall sufficient
May 2.2" 10.1" 0" ✅ Rainfall sufficient
Jun 2.2" 9.4" 0" ✅ Rainfall sufficient
Jul 2.2" 9.3" 0" ✅ Rainfall sufficient
Aug 2.2" 8.7" 0" ✅ Rainfall sufficient
Sep 2.2" 6.9" 0" ✅ Rainfall sufficient
Oct 2.2" 4.5" 0" ✅ Rainfall sufficient
Nov 2.2" 2.5" 0" ✅ Rainfall sufficient
Dec 2.2" 1.8" 0.4" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Hidalgo 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 ~1,500 GDD — county provides 7,900 GDD Excellent fit

Marigolds Planting Timeline — Hidalgo County, TX

Marigolds Planting Calendar

Activity When Date Range
Start Indoors January 2 Jan 2 – Jan 16
Transplant Outdoors January 2 Jan 2 – Jan 16
Direct Sow January 2 Jan 2 – Jan 23
Bloom February 27 Feb 27 – Sep 4

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

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors Direct Sow
February Bloom
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: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

315 days in Hidalgo County

Growing Tips for Marigolds in Hidalgo County

Direct sow Marigolds outdoors after February 06 in Hidalgo County when soil has warmed and frost danger has passed.

With summer highs reaching 100°F in Hidalgo 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 67" of annual rainfall in Hidalgo 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 Hidalgo County, TX?

Hidalgo County is in Zone 10a with an average last frost of February 6. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hidalgo County, TX?

Hidalgo County, Texas is in USDA Hardiness Zone 10a. The average last spring frost is February 6 and first fall frost is December 18.

🌱

Your Hidalgo County Garden Planner — Free

A 22-page printable planner built for Hidalgo County (Zone 10a). 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 Hidalgo 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.