Blog

When to Plant Jicama in San Luis Obispo County, CA

San Luis Obispo County, California Zone 10a May

Your May game plan for San Luis Obispo County, California

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 23
Avg. first frost November 9
Soil temp (4") 71°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs
  1. Indoor seed-starting week for jicama

    You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.

Instant PDF download. No spam, unsubscribe any time.

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 Luis Obispo County, California is in USDA Zone 10a. The average last spring frost is March 23 and the first fall frost is November 9, giving you a growing season of approximately 231 days.

At an elevation of 2,412 feet, San Luis Obispo County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98°F, so Jicama may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Jicama successfully. Mulch heavily to conserve soil moisture.

San Luis Obispo County, CA (Zone 10a) Long season
231 days
Last Spring Frost March 23
231 growing days
First Fall Frost November 9
Share this guide:

San Luis Obispo County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (38 days to spare)
Start indoors: Jan 22 Transplant: Mar 12 🍅 Harvest: Jul 16 – Sep 24
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Feb 9 Transplant: Mar 30 🍅 Harvest: Aug 3 – Oct 12
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Mar 5 Transplant: Apr 23 🍅 Harvest: Aug 27 – Nov 5

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 Luis Obispo County

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

Soil pH

Your soil pH (6.6–7.8) overlaps with Jicama's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,642 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 4" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.3" 2.8" 1.5" 💧 Light watering
Apr 4.3" 1.6" 2.7" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.8" 3.5" 🚿 Regular watering
Nov 4.3" 1.8" 2.5" 🚿 Regular watering
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in San Luis Obispo 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 ~3,525 GDD — county provides 5,428 GDD Excellent fit

Jicama Planting Timeline — San Luis Obispo County, CA

Jicama Planting Calendar

Activity When Date Range
Start Indoors February 9 Feb 9 – Feb 23
Transplant Outdoors March 30 Mar 30 – Apr 13
Direct Sow March 23 Mar 23 – Apr 13
Harvest August 3 Aug 3 – Oct 12

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

231 days in San Luis Obispo County

Growing Tips for Jicama in San Luis Obispo County

Direct sow Jicama outdoors after March 23 in San Luis Obispo County when soil has warmed and frost danger has passed.

With summer highs reaching 98°F in San Luis Obispo County, provide afternoon shade for Jicama and water deeply in the morning.

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

San Luis Obispo County receives only 18" 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 Luis Obispo County, CA?

San Luis Obispo County is in Zone 10a with an average last frost of March 23. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Luis Obispo County, CA?

San Luis Obispo County, California is in USDA Hardiness Zone 10a. The average last spring frost is March 23 and first fall frost is November 9.

🌱

Your San Luis Obispo County Garden Planner — Free

A 24-page printable planner built for San Luis Obispo County (Zone 10a). 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 San Luis Obispo County, CA. 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.