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When to Plant Tomatoes in Oklahoma County, OK

Oklahoma County, Oklahoma Zone 7b May

Your May planting checklist for Oklahoma County, Oklahoma

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 2
Avg. first frost November 5
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Indoor seed-starting week for tomatoes

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

Get ahead of June
  • 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.

Oklahoma County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 5, giving you a growing season of approximately 217 days.

At an elevation of 739 feet, Oklahoma County receives approximately 26.6 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Tomatoes during the growing season.

Oklahoma County, OK (Zone 7b) Long season
217 days
Last Spring Frost April 2
217 growing days
First Fall Frost November 5

Oklahoma County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Jan 31 Transplant: Apr 4 🍅 Harvest: Jun 6 – Aug 15
Recommended (50%) ✓ Fits season (70 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jun 18 – Aug 27
Safe Start (90%) ✓ Fits season (73 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 1 – Sep 9

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 Oklahoma County

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

Soil pH

Your soil pH (6.5–7.6) is more alkaline than Tomatoes prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

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

Succession Planting Tomatoes

4
successive plantings in your 217-day season

Sow every 6.9 weeks. Last sowing by Aug 12 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.5″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,588 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.7" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 5.2" 2.9" 2.3" 💧 Light watering
May 5.2" 4.3" 0.9" 💧 Light watering
Jun 5.2" 3.9" 1.3" 💧 Light watering
Jul 5.2" 3.6" 1.6" 💧 Light watering
Aug 5.2" 3.1" 2.1" 💧 Light watering
Sep 5.2" 2.5" 2.7" 🚿 Regular watering
Oct 5.2" 1.4" 3.8" 🚿 Regular watering
Nov 5.2" 0.9" 4.3" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Oklahoma 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 ~1,160 GDD — county provides 3,472 GDD Excellent fit

Tomatoes Planting Timeline — Oklahoma County, OK

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 – Feb 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 9 Apr 9 – Apr 30
Harvest June 18 Jun 18 – Aug 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 2-3 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

217 days in Oklahoma County

Growing Tips for Tomatoes in Oklahoma County

Direct sow Tomatoes outdoors after April 02 in Oklahoma County when soil has warmed and frost danger has passed.

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.

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 Oklahoma County, OK?

Oklahoma County is in Zone 7b with an average last frost of April 2. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oklahoma County, OK?

Oklahoma County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is November 5.

🌱

Your Oklahoma County Garden Planner — Free

A 24-page printable planner built for Oklahoma County (Zone 7b). 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 Oklahoma County, OK. 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.