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When to Plant Geraniums in Guadalupe County, TX

Guadalupe County, Texas Zone 9a June

Your June planting checklist for Guadalupe County, Texas

A quick June briefing for Guadalupe County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 7
Avg. first frost November 21
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. It's harvest week for geraniums

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

To set up a strong July, finish these tasks
  • 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.

Guadalupe County, Texas is in USDA Zone 9a. The average last spring frost is March 7 and the first fall frost is November 21, giving you a growing season of approximately 259 days.

At an elevation of 3,679 feet, Guadalupe County receives approximately 63 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Geraniums during the growing season. Clay soil retains moisture well for Geraniums, but amend with compost to improve drainage and prevent root rot. 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
Guadalupe County, TX (Zone 9a) Long season
259 days
Last Spring Frost March 7
259 growing days
First Fall Frost November 21

Guadalupe County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.2

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Dec 19 Transplant: Feb 6 🌸 Bloom: Apr 17 – Oct 16
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Dec 27 Transplant: Feb 14 🌸 Bloom: Apr 25 – Oct 24
Safe Start (90%) ✓ Fits season (18 days to spare)
Start indoors: Jan 26 Transplant: Mar 16 🌸 Bloom: May 25 – Nov 23

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 Guadalupe County

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

Soil pH

Your soil pH (6.9–8.2) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Guadalupe County is workable for Geraniums. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Geraniums.

How to Plant Geraniums

0.1"
Planting Depth
12"
Between Plants
14"
Between Rows

Succession Planting Geraniums

4
successive plantings in your 259-day season

Sow every 8 weeks. Last sowing by Aug 13 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/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 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 1.6" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 6.5" 0" ✅ Rainfall sufficient
May 4.3" 9.5" 0" ✅ Rainfall sufficient
Jun 4.3" 9.3" 0" ✅ Rainfall sufficient
Jul 4.3" 8" 0" ✅ Rainfall sufficient
Aug 4.3" 7.1" 0" ✅ Rainfall sufficient
Sep 4.3" 6.4" 0" ✅ Rainfall sufficient
Oct 4.3" 4.5" 0" ✅ Rainfall sufficient
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Guadalupe 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 ~1,679 GDD — county provides 5,115 GDD Excellent fit

Geraniums Planting Timeline — Guadalupe County, TX

Geraniums Planting Calendar

Activity When Date Range
Start Indoors December 27 Dec 27 – Jan 10
Transplant Outdoors February 14 Feb 14 – Feb 28
Bloom April 25 Apr 25 – Oct 24

Plant 0.1" deep · 12" apart · Rows 14" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

259 days in Guadalupe County

Growing Tips for Geraniums in Guadalupe County

Direct sow Geraniums outdoors after March 07 in Guadalupe County when soil has warmed and frost danger has passed.

With Guadalupe County's clay soil (40% clay), work in 3-4 inches of compost before planting Geraniums. Avoid tilling when soil is wet to prevent compaction.

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 Guadalupe County, TX?

Guadalupe County is in Zone 9a with an average last frost of March 7. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Guadalupe County, TX?

Guadalupe County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 7 and first fall frost is November 21.

🌱

Your Guadalupe County Garden Planner — Free

A 22-page printable planner built for Guadalupe 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 Guadalupe County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

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