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When to Plant Luffa in Johnston County, OK

Luffa is a tropical vine that produces edible young fruits and natural sponges from mature dried fruits. Young fruits are eaten like zucchini in many Asian cuisines.

Johnston County, Oklahoma is in USDA Zone 7b. 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 92ยฐF, providing good warmth for Luffa during the growing season.

Johnston County, OK (Zone 7b) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11

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 (50 days to spare)
Start indoors: Jan 23 Transplant: Mar 27 🍅 Harvest: Jun 26 – Sep 11
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Sep 23
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 29 – Oct 14

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.

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
Luffa needs ~2,280 GDD — county provides 4,389 GDD Excellent fit

Luffa Planting Timeline โ€” Johnston County, OK

Luffa Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 โ€“ Feb 18
Transplant Outdoors April 8 Apr 8 โ€“ Apr 22
Direct Sow April 1 Apr 1 โ€“ Apr 22
Harvest July 8 Jul 8 โ€“ Sep 23

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“150 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 7b

Growing Season

231 days

Growing Tips for Johnston County

Start seeds indoors 4-6 weeks early. Provide a very strong trellis for heavy vines. Harvest young for eating or let mature fully on the vine for sponges. Requires a long, hot season.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Luffa in Johnston County, OK?

Johnston County is in Zone 7b with an average last frost of March 25. Plan your Luffa planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Johnston County, OK?

Johnston County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 25 and first fall frost is November 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Johnston County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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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, OK. Local conditions may vary. Last updated: April 2026.