Blog

When to Plant Peppers in Jefferson County, OK

Jefferson County, Oklahoma Zone 8a May

May in Jefferson County, Oklahoma — your action list

Each item below is timed to Jefferson County, Oklahoma's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 26
Avg. first frost November 9
Soil temp (4") 67°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Time to start peppers inside

    These need a head start before your last frost (March 26). Sow into cells now so you're ready to transplant in a few weeks.

Get ahead of June
  • First harvests: peppers

Instant PDF download. No spam, unsubscribe any time.

Sweet peppers are warm-season crops producing fruits in a rainbow of colors. They turn from green to red, yellow, or orange as they ripen, increasing in sweetness.

Jefferson County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 9, giving you a growing season of approximately 228 days.

At an elevation of 883 feet, Jefferson County receives approximately 24.7 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Peppers during the growing season.

Jefferson County, OK (Zone 8a) Long season
228 days
Last Spring Frost March 26
228 growing days
First Fall Frost November 9
Share this guide:

Jefferson County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (82 days to spare)
Start indoors: Jan 12 Transplant: Mar 30 🍅 Harvest: Jun 1 – Aug 10
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Jan 22 Transplant: Apr 9 🍅 Harvest: Jun 11 – Aug 20
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Feb 11 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 Jefferson County

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

Soil pH

Your soil pH (6.6–7.5) is more alkaline than Peppers prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Peppers will thrive.

How to Plant Peppers

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Peppers

4
successive plantings in your 228-day season

Sow every 6.9 weeks. Last sowing by Aug 11 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.5″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,309 gal / 100 sq ft

Monthly Watering Guide for Peppers

Peppers needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Peppers Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 4.8" 1.7" 3.1" 🚿 Regular watering
Apr 4.8" 2.7" 2.1" 💧 Light watering
May 4.8" 3.2" 1.6" 💧 Light watering
Jun 4.8" 4" 0.8" 💧 Light watering
Jul 4.8" 3.1" 1.7" 💧 Light watering
Aug 4.8" 3.2" 1.6" 💧 Light watering
Sep 4.8" 2.1" 2.7" 🚿 Regular watering
Oct 4.8" 1.6" 3.2" 🚿 Regular watering
Nov 4.8" 0.8" 4" 🚿 Regular watering
Dec 0.7" 0" ❄️ Dormant

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

Peppers 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.

Peppers needs ~1,369 GDD — county provides 4,161 GDD Excellent fit

Peppers Planting Timeline — Jefferson County, OK

Peppers Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 – Feb 5
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow April 2 Apr 2 – Apr 23
Harvest June 11 Jun 11 – Aug 20

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

228 days in Jefferson County

Growing Tips for Peppers in Jefferson County

Direct sow Peppers outdoors after March 26 in Jefferson County when soil has warmed and frost danger has passed.

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

Jefferson County receives only 25" of rain annually. Peppers needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 8-10 weeks before last frost. Transplant when nighttime temperatures stay above 55F. Avoid high-nitrogen fertilizers which promote leaves over fruit.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Peppers Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Remove seeds from fully ripe (red/orange) fruit.
Storage Store airtight; viable 4 years at 35°F, under 50% humidity.

Isolate 300 ft for purity. Hot and sweet peppers can cross-pollinate.

Frequently Asked Questions

When should I plant Peppers in Jefferson County, OK?

Jefferson County is in Zone 8a with an average last frost of March 26. Plan your Peppers planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, OK?

Jefferson County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 9.

🌱

Your Jefferson County Garden Planner — Free

A 24-page printable planner built for Jefferson 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jefferson 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.