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When to Plant Cucumber in Jefferson County, OK

Jefferson County, Oklahoma Zone 8a May

What to do in May

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
June prep starts now
  • First harvests: cucumber

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Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

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 Cucumber 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
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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 (103 days to spare)
Start indoors: Feb 16 Transplant: Mar 30 🍅 Harvest: May 25 – Jul 20
Recommended (50%) ✓ Fits season (102 days to spare)
Start indoors: Feb 26 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 30
Safe Start (90%) ✓ Fits season (97 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 19

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 Cucumber's growing requirements.

Soil pH

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

Soil Texture

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

Organic Matter

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

How to Plant Cucumber

0.5"
Planting Depth
24"
Between Plants
48"
Between Rows

Succession Planting Cucumber

5
successive plantings in your 228-day season

Sow every 5.7 weeks. Last sowing by Aug 31 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,121 gal / 100 sq ft

Monthly Watering Guide for Cucumber

Cucumber needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Cucumber Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 6.5" 1.7" 4.8" 🚿 Regular watering
Apr 6.5" 2.7" 3.8" 🚿 Regular watering
May 6.5" 3.2" 3.3" 🚿 Regular watering
Jun 6.5" 4" 2.5" 💧 Light watering
Jul 6.5" 3.1" 3.4" 🚿 Regular watering
Aug 6.5" 3.2" 3.3" 🚿 Regular watering
Sep 6.5" 2.1" 4.4" 🚿 Regular watering
Oct 6.5" 1.6" 4.9" 🚿 Regular watering
Nov 6.5" 0.8" 5.7" 🚿 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.

Cucumber 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.

Cucumber needs ~1,095 GDD — county provides 4,161 GDD Excellent fit

Cucumber Planting Timeline — Jefferson County, OK

Cucumber Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow April 2 Apr 2 – Apr 23
Harvest June 4 Jun 4 – Jul 30

Plant 0.5" deep · 24" apart · Rows 48" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

228 days in Jefferson County

Growing Tips for Cucumber in Jefferson County

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

Common pests for Cucumber in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

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

General growing tips

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cucumber in Jefferson County, OK?

Jefferson County is in Zone 8a with an average last frost of March 26. Plan your Cucumber 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.

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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 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.