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When to Plant Geraniums in Tom Green County, TX

Tom Green County, Texas Zone 8a 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 Tom Green County, Texas.

Avg. last frost March 25
Avg. first frost November 12
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Start harvesting geraniums

    If you can't use it all right away, check the food-preservation section of your planner.

August prep starts now
  • 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.

Tom Green County, Texas is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 12, giving you a growing season of approximately 232 days.

At an elevation of 4,366 feet, Tom Green County receives approximately 52.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Geraniums may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Geraniums will need more frequent watering and organic matter to retain nutrients. 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
Tom Green County, TX (Zone 8a) Long season
232 days
Last Spring Frost March 25
232 growing days
First Fall Frost November 12

Tom Green County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Start indoors: Jan 1 Transplant: Mar 5 🌸 Bloom: May 14 – Oct 1
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Jan 14 Transplant: Mar 18 🌸 Bloom: May 27 – Oct 14
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🌸 Bloom: Jun 16 – Nov 3

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 Tom Green County

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

Soil pH

Your soil pH (7.2–8.3) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Tom Green County warms quickly in spring but drains fast. Geraniums will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Geraniums.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Geraniums.

How to Plant Geraniums

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

Succession Planting Geraniums

3
successive plantings in your 232-day season

Sow every 8 weeks. Last sowing by Aug 04 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 875 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 3" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.3" 3.1" 1.2" 💧 Light watering
Apr 4.3" 1.5" 2.8" 🚿 Regular watering
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 9.5" 0" ✅ Rainfall sufficient
Aug 4.3" 10.3" 0" ✅ Rainfall sufficient
Sep 4.3" 7.4" 0" ✅ Rainfall sufficient
Oct 4.3" 4.8" 0" ✅ Rainfall sufficient
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tom Green 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 ~2,252 GDD — county provides 6,148 GDD Excellent fit

Geraniums Planting Timeline — Tom Green County, TX

Geraniums Planting Calendar

Activity When Date Range
Start Indoors January 14 Jan 14 – Jan 28
Transplant Outdoors March 18 Mar 18 – Apr 1
Bloom May 27 May 27 – Oct 14

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

232 days in Tom Green County

Growing Tips for Geraniums in Tom Green County

Direct sow Geraniums outdoors after March 25 in Tom Green County when soil has warmed and frost danger has passed.

Sandy soil in Tom Green County dries quickly — mulch Geraniums with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 102°F in Tom Green 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 Tom Green County, TX?

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

What planting zone is Tom Green County, TX?

Tom Green County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 12.

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Your Tom Green County Garden Planner — Free

A 22-page printable planner built for Tom Green County (Zone 8a). 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 Tom Green 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.