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When to Plant Malabar Spinach in Harmon County, OK

Malabar spinach is a tropical vine with thick, succulent leaves that taste similar to spinach. Unlike true spinach, it thrives in heat and humidity.

Harmon County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 5, giving you a growing season of approximately 219 days.

At an elevation of 993 feet, Harmon County receives approximately 34.4 inches of rainfall annually with predominantly loam soil. Summer highs average 91ยฐF, providing good warmth for Malabar Spinach during the growing season.

Harmon County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 31
219 growing days
First Fall Frost November 5

Harmon County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (121 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🍅 Harvest: Jun 1 – Jun 29
Recommended (50%) ✓ Fits season (121 days to spare)
Start indoors: Feb 10 Transplant: Apr 14 🍅 Harvest: Jun 9 – Jul 7
Safe Start (90%) ✓ Fits season (121 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jun 24 – Jul 22

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 Harmon County

How your county's soil matches Malabar Spinach's growing requirements.

Soil pH

Your soil pH (6.5โ€“7.5) is within Malabar Spinach's preferred range (6.0โ€“7.5).

Soil Texture

The loam soil in Harmon County is excellent for Malabar Spinach โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.0%) โ€” Malabar Spinach will thrive.

How to Plant Malabar Spinach

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Succession Planting Malabar Spinach

4
successive plantings in your 219-day season

Sow every 6.3 weeks. Last sowing by Aug 27 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,965 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Malabar Spinach

Malabar Spinach 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 Malabar Spinach Needs Rainfall You Supplement Action
Jan โ€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar 6.5" 2.3" 4.2" ๐Ÿšฟ Regular watering
Apr 6.5" 3.7" 2.8" ๐Ÿ’ง Light watering
May 6.5" 5.1" 1.4" ๐Ÿ’ง Light watering
Jun 6.5" 5" 1.5" ๐Ÿ’ง Light watering
Jul 6.5" 4.1" 2.4" ๐Ÿ’ง Light watering
Aug 6.5" 4.8" 1.7" ๐Ÿ’ง Light watering
Sep 6.5" 3" 3.5" ๐Ÿšฟ Regular watering
Oct 6.5" 2" 4.5" ๐Ÿšฟ Regular watering
Nov 6.5" 1.3" 5.2" ๐Ÿšฟ Regular watering
Dec โ€” 1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Harmon County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Malabar Spinach 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" โ€” every day above 50ยฐF 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.

Malabar Spinach needs ~1,141 GDD — county provides 3,996 GDD Excellent fit

Malabar Spinach Planting Timeline โ€” Harmon County, OK

Malabar Spinach Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 โ€“ Feb 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow April 7 Apr 7 โ€“ Apr 28
Harvest June 9 Jun 9 โ€“ Jul 7

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

55โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

219 days in Harmon County

Growing Tips for Malabar Spinach in Harmon County

Direct sow Malabar Spinach outdoors after March 31 in Harmon County when soil has warmed and frost danger has passed.

General growing tips

Direct sow after last frost or start indoors. Provide a trellis for the vigorous vines. Harvest young leaves regularly; older leaves become mucilaginous when cooked.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Malabar Spinach in Harmon County, OK?

Harmon County is in Zone 7b with an average last frost of March 31. Plan your Malabar Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harmon County, OK?

Harmon County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 5.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Harmon County, OK. Local conditions may vary. Last updated: April 2026.