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When to Plant Cucumber in Johnston County, NC

Johnston County, North Carolina Zone 8a May

Your May game plan for Johnston County, North Carolina

May is a pivotal month for Johnston County, North Carolina gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 3
Avg. first frost November 3
Soil temp (4") 66°F
Watering Moderate
Pest pressure Moderate
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: cucumber

    Label every cell. You will absolutely forget which is which otherwise.

Before June arrives, get these ready
  • 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.

Johnston County, North Carolina is in USDA Zone 8a. The average last spring frost is April 3 and the first fall frost is November 3, giving you a growing season of approximately 214 days.

At an elevation of 1,120 feet, Johnston County receives approximately 49.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 92°F, providing good warmth for Cucumber during the growing season. Clay soil retains moisture well for Cucumber, but amend with compost to improve drainage and prevent root rot.

Johnston County, NC (Zone 8a) Long season
214 days
Last Spring Frost April 3
214 growing days
First Fall Frost November 3
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Johnston County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Start indoors: Feb 27 Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 31
Recommended (50%) ✓ Fits season (88 days to spare)
Start indoors: Mar 6 Transplant: Apr 17 🍅 Harvest: Jun 12 – Aug 7
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 1

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 Johnston County

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

Soil pH

Your soil pH (5.6–6.7) overlaps with Cucumber's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Cucumber.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Cucumber.

How to Plant Cucumber

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

Succession Planting Cucumber

5
successive plantings in your 214-day season

Sow every 5.7 weeks. Last sowing by Aug 25 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 153 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 4.4" 0" ❄️ Dormant
Feb 4.4" 0" ❄️ Dormant
Mar 5.3" 0" ❄️ Dormant
Apr 6.5" 4.1" 2.4" 💧 Light watering
May 6.5" 3.3" 3.2" 💧 Light watering
Jun 6.5" 4.4" 2.1" 💧 Light watering
Jul 6.5" 4.4" 2.1" 💧 Light watering
Aug 6.5" 4.1" 2.4" 💧 Light watering
Sep 6.5" 4.2" 2.3" 💧 Light watering
Oct 6.5" 2.7" 3.8" 🚿 Regular watering
Nov 6.5" 3.9" 2.6" 💧 Light watering
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Johnston 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 ~1,140 GDD — county provides 4,066 GDD Excellent fit

Cucumber Planting Timeline — Johnston County, NC

Cucumber Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 10 Apr 10 – May 1
Harvest June 12 Jun 12 – Aug 7

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

214 days in Johnston County

Growing Tips for Cucumber in Johnston County

Direct sow Cucumber outdoors after April 03 in Johnston County when soil has warmed and frost danger has passed.

With Johnston County's clay soil (34% clay), work in 3-4 inches of compost before planting Cucumber. Avoid tilling when soil is wet to prevent compaction.

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.

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 Johnston County, NC?

Johnston County is in Zone 8a with an average last frost of April 3. Plan your Cucumber planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnston County, NC?

Johnston County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is April 3 and first fall frost is November 3.

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Your Johnston County Garden Planner — Free

A 24-page printable planner built for Johnston 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 Johnston County, NC. 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.