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When to Plant Jicama in San Juan County, NM

San Juan County, New Mexico Zone 7a May

May in the garden — San Juan County, New Mexico

Each item below is timed to San Juan County, New Mexico's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 12
Avg. first frost October 6
Soil temp (4") 32°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Transplant jicama outside

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Put jicama seeds straight in the ground

    Your soil is 32°F — warm enough for these to germinate without babying.

To set up a strong June, finish these tasks
  • Starting indoors: jicama

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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.

San Juan County, New Mexico is in USDA Zone 7a. The average last spring frost is May 12 and the first fall frost is October 6, giving you a growing season of approximately 147 days.

At an elevation of 8,301 feet, San Juan County receives approximately 14.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Jicama during the growing season. Sandy soil warms quickly in spring — great for early planting — but Jicama will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Jicama successfully. Mulch heavily to conserve soil moisture.

San Juan County, NM (Zone 7a) Short season
147 days
Last Spring Frost May 12
147 growing days
First Fall Frost October 6
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San Juan County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 17 Transplant: May 19 🍅 Harvest: Sep 22 – Dec 1
Recommended (50%) ✗ May not fit
Start indoors: Mar 24 Transplant: May 26 🍅 Harvest: Sep 29 – Dec 8
Safe Start (90%) ✗ May not fit
Start indoors: Apr 14 Transplant: Jun 16 🍅 Harvest: Oct 20 – Dec 29

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 San Juan County

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

Soil pH

Your soil pH (7.3–8.5) is more alkaline than Jicama prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in San Juan County warms quickly in spring but drains fast. Jicama will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Jicama.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting 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
0.4″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,400 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 1.1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.5" 0" ❄️ Dormant
May 4.3" 0.3" 4" 🚿 Regular watering
Jun 4.3" 0.5" 3.8" 🚿 Regular watering
Jul 4.3" 2.5" 1.8" 💧 Light watering
Aug 4.3" 2.6" 1.7" 💧 Light watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.3" 1.3" 3" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in San Juan 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 ~2,288 GDD — county provides 2,241 GDD Tight fit

Jicama Planting Timeline — San Juan County, NM

Jicama Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Harvest September 29 Sep 29 – Dec 8

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

147 days in San Juan County

Growing Tips for Jicama in San Juan County

Direct sow Jicama outdoors after May 12 in San Juan County when soil has warmed and frost danger has passed.

Sandy soil in San Juan County dries quickly — mulch Jicama with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your 147.0-day growing season in San Juan County is tight for Jicama (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

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

San Juan County receives only 14" of rain annually. Jicama needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 San Juan County, NM?

San Juan County is in Zone 7a with an average last frost of May 12. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Juan County, NM?

San Juan County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is May 12 and first fall frost is October 6.

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Your San Juan County Garden Planner — Free

A 24-page printable planner built for San Juan 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 San Juan County, NM. 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.