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When to Plant Geraniums in Hidalgo County, TX

Hidalgo County, Texas Zone 10a July

Your July planting checklist for Hidalgo County, Texas

Welcome to July in Zone 10a. These are the moves that will have the biggest impact on your growing season.

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. Pick geraniums

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Looking ahead to August
  • First harvests: geraniums

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Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.

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 Geraniums may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Geraniums 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

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Start indoors: Nov 9 Transplant: Dec 7 🌸 Bloom: Feb 15 – Sep 13
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Nov 28 Transplant: Dec 26 🌸 Bloom: Mar 6 – Oct 2
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Dec 25 Transplant: Jan 22 🌸 Bloom: Apr 2 – Oct 29

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 Geraniums's growing requirements.

Soil pH

Your soil pH (6.2–7.8) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Geraniums

0.1"
Planting Depth
14"
Between Plants
16"
Between Rows

Succession Planting Geraniums

5
successive plantings in your 315-day season

Sow every 8 weeks. Last sowing by Sep 09 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 308 gal / 100 sq ft

Monthly Watering Guide for Geraniums

Geraniums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Geraniums Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 4.3" 2.1" 2.2" 🚿 Regular watering
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 6.7" 0" ✅ Rainfall sufficient
May 4.3" 10.1" 0" ✅ Rainfall sufficient
Jun 4.3" 9.4" 0" ✅ Rainfall sufficient
Jul 4.3" 9.3" 0" ✅ Rainfall sufficient
Aug 4.3" 8.7" 0" ✅ Rainfall sufficient
Sep 4.3" 6.9" 0" ✅ Rainfall sufficient
Oct 4.3" 4.5" 0" ✅ Rainfall sufficient
Nov 4.3" 2.5" 1.8" 💧 Light watering
Dec 4.3" 1.8" 2.5" 🚿 Regular 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.

Geraniums 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.

Geraniums needs ~2,125 GDD — county provides 7,900 GDD Excellent fit

Geraniums Planting Timeline — Hidalgo County, TX

Geraniums Planting Calendar

Activity When Date Range
Start Indoors November 28 Nov 28 – Dec 12
Transplant Outdoors December 26 Dec 26 – Jan 9
Bloom March 6 Mar 6 – Oct 2

Plant 0.1" deep · 14" apart · Rows 16" apart

Month-by-Month Timeline

MonthActivities
January Transplant Outdoors
February
March Bloom
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November Start Indoors
December Start Indoors Transplant Outdoors

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

315 days in Hidalgo County

Growing Tips for Geraniums in Hidalgo County

Direct sow Geraniums 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 Geraniums and water deeply in the morning.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Geraniums in Hidalgo County, TX?

Hidalgo County is in Zone 10a with an average last frost of February 6. Plan your Geraniums 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.

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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 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.