Blog

When to Plant Squash (Summer) in Johnston County, OK

Johnston County, Oklahoma Zone 8a May

May to-do list for Johnston County, Oklahoma

A quick May briefing for Johnston County, Oklahoma gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 25
Avg. first frost November 11
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Bring in the squash (summer)

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

A few tasks this May that'll pay off in June
  • First harvests: squash (summer)

Instant PDF download. No spam, unsubscribe any time.

Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Johnston County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.

At an elevation of 700 feet, Johnston County receives approximately 32.9 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Squash (Summer) during the growing season.

Johnston County, OK (Zone 8a) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11
Share this guide:

Johnston County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (106 days to spare)
Start indoors: Feb 13 Transplant: Mar 27 🍅 Harvest: May 15 – Jul 17
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Feb 25 Transplant: Apr 8 🍅 Harvest: May 27 – Jul 29
Safe Start (90%) ✓ Fits season (102 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🍅 Harvest: Jun 17 – 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 Johnston County

How your county's soil matches Squash (Summer)'s growing requirements.

Soil pH

Your soil pH (6.3–7.3) is within Squash (Summer)'s preferred range (6.0–7.5).

Soil Texture

The loam soil in Johnston County is excellent for Squash (Summer) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.2%) — Squash (Summer) will thrive.

How to Plant Squash (Summer)

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Squash (Summer)

6
successive plantings in your 231-day season

Sow every 5.1 weeks. Last sowing by Sep 07 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 826 gal / 100 sq ft

Monthly Watering Guide for Squash (Summer)

Squash (Summer) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Squash (Summer) Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 4.3" 2.3" 2" 💧 Light watering
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 5.1" 0" ✅ Rainfall sufficient
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 4.3" 1" 3.3" 🚿 Regular watering
Dec 0.8" 0" ❄️ Dormant

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

Squash (Summer) 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.

Squash (Summer) needs ~1,045 GDD — county provides 4,389 GDD Excellent fit

Squash (Summer) Planting Timeline — Johnston County, OK

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors April 8 Apr 8 – Apr 22
Direct Sow April 1 Apr 1 – Apr 22
Harvest May 27 May 27 – Jul 29

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

231 days in Johnston County

Growing Tips for Squash (Summer) in Johnston County

Direct sow Squash (Summer) outdoors after March 25 in Johnston County when soil has warmed and frost danger has passed.

Your generous 231.0-day season in Johnston County allows multiple plantings of Squash (Summer). Sow every 22.0 days for continuous harvest.

Common pests for Squash (Summer) 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 on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Johnston County, OK?

Johnston County is in Zone 8a with an average last frost of March 25. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnston County, OK?

Johnston County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 11.

🌱

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.

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 Johnston 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.