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When to Plant Jicama in Grant County, OK

Grant County, Oklahoma Zone 7a May

Your May game plan for Grant County, Oklahoma

Here's what deserves your attention in Grant County, Oklahoma this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 11
Avg. first frost October 27
Soil temp (4") 64°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Start jicama indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

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Jicama is a tropical legume grown for its crisp, sweet, starchy root. It requires a very long, warm growing season but produces a refreshing, water chestnut-like tuber.

Grant County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 27, giving you a growing season of approximately 199 days.

At an elevation of 564 feet, Grant County receives approximately 25.7 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Jicama during the growing season.

Grant County, OK (Zone 7a) Moderate season
199 days
Last Spring Frost April 11
199 growing days
First Fall Frost October 27

Grant County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 13 Transplant: Apr 17 🍅 Harvest: Aug 21 – Oct 30
Recommended (50%) ✗ May not fit
Start indoors: Feb 21 Transplant: Apr 25 🍅 Harvest: Aug 29 – Nov 7
Safe Start (90%) ✗ May not fit
Start indoors: Mar 5 Transplant: May 7 🍅 Harvest: Sep 10 – Nov 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 Grant County

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

Soil pH

Your soil pH (6.5–7.2) is within Jicama's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Jicama.

How to Plant Jicama

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 973 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Jicama

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

Month Jicama Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.1" 1.2" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 4.3" 1.5" 2.8" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

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

Jicama 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.

Jicama needs ~2,512 GDD — county provides 3,333 GDD Excellent fit

Jicama Planting Timeline — Grant County, OK

Jicama Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 18 Apr 18 – May 9
Harvest August 29 Aug 29 – Nov 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

199 days in Grant County

Growing Tips for Jicama in Grant County

Direct sow Jicama outdoors after April 11 in Grant County when soil has warmed and frost danger has passed.

Common pests for Jicama in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before last frost. Pinch off flowers to direct energy to root development. Harvest before first frost when roots are 3-6 inches across.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Jicama in Grant County, OK?

Grant County is in Zone 7a with an average last frost of April 11. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, OK?

Grant County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 27.

🌱

Your Grant County Garden Planner — Free

A 24-page printable planner built for Grant County (Zone 7a). 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 Grant 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.