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When to Plant Tomatoes in Colorado County, TX

Colorado County, Texas Zone 9a May

Your May game plan for Colorado County, Texas

Your Colorado County, Texas garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 26
Avg. first frost December 4
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Pick tomatoes

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

Before June arrives, get these ready
  • First harvests: tomatoes

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Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Colorado County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is December 4, giving you a growing season of approximately 281 days.

At an elevation of 87 feet, Colorado County receives approximately 70.5 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Tomatoes during the growing season. Clay soil retains moisture well for Tomatoes, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Tomatoes root diseases.

Colorado County, TX (Zone 9a) Year-round
281 days
Last Spring Frost February 26
281 growing days
First Fall Frost December 4

Colorado County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Start indoors: Jan 1 Transplant: Feb 19 🍅 Harvest: Apr 23 – Jul 2
Recommended (50%) ✓ Fits season (141 days to spare)
Start indoors: Jan 15 Transplant: Mar 5 🍅 Harvest: May 7 – Jul 16
Safe Start (90%) ✓ Fits season (133 days to spare)
Start indoors: Feb 6 Transplant: Mar 27 🍅 Harvest: May 29 – Aug 7

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 Colorado County

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

Soil pH

Your soil pH (7.3–7.8) is more alkaline than Tomatoes prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (42% clay) in Colorado County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Drainage

Drainage is adequate for Tomatoes.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

5
successive plantings in your 281-day season

Sow every 6.9 weeks. Last sowing by Sep 10 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan 1.9" 0" ❄️ Dormant
Feb 5.2" 2.3" 2.9" 🚿 Regular watering
Mar 5.2" 4.5" 0.7" 💧 Light watering
Apr 5.2" 8" 0" ✅ Rainfall sufficient
May 5.2" 10.9" 0" ✅ Rainfall sufficient
Jun 5.2" 10.3" 0" ✅ Rainfall sufficient
Jul 5.2" 9.3" 0" ✅ Rainfall sufficient
Aug 5.2" 8.7" 0" ✅ Rainfall sufficient
Sep 5.2" 5.5" 0" ✅ Rainfall sufficient
Oct 5.2" 4.8" 0.4" 💧 Light watering
Nov 5.2" 2.3" 2.9" 🚿 Regular watering
Dec 5.2" 1.9" 3.3" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Colorado County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Tomatoes 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.

Tomatoes needs ~1,269 GDD — county provides 4,935 GDD Excellent fit

Tomatoes Planting Timeline — Colorado County, TX

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors January 15 Jan 15 – Jan 29
Transplant Outdoors March 5 Mar 5 – Mar 19
Direct Sow February 26 Feb 26 – Mar 19
Harvest May 7 May 7 – Jul 16

Plant 0.5" deep · 24" apart · Rows 36" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · Natural rainfall sufficient

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

281 days in Colorado County

Growing Tips for Tomatoes in Colorado County

Direct sow Tomatoes outdoors after February 26 in Colorado County when soil has warmed and frost danger has passed.

With Colorado County's clay soil (42% clay), work in 3-4 inches of compost before planting Tomatoes. Avoid tilling when soil is wet to prevent compaction.

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Recommended Tomatoes Varieties for Colorado County

Your long season supports large indeterminate heirloom types

Brandywine (80d) Cherokee Purple (80d) San Marzano (80d) Mortgage Lifter (85d)

Disease-resistant varieties for your humid climate

Mountain Merit (VF) Defiant (LB) Iron Lady (EB/LB/SF)

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Colorado County, TX?

Colorado County is in Zone 9a with an average last frost of February 26. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Colorado County, TX?

Colorado County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is December 4.

🌱

Your Colorado County Garden Planner — Free

A 24-page printable planner built for Colorado 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 Colorado 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.