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When to Plant Jicama in Solano County, CA

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.

Solano County, California is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 3, giving you a growing season of approximately 297 days.

At an elevation of 376 feet, Solano County receives approximately 40.4 inches of rainfall annually with predominantly loam soil. Summer highs average 95ยฐF, so Jicama may need afternoon shade and extra watering during peak heat.

Solano County, CA (Zone 9a) Year-round
297 days
Last Spring Frost February 9
297 growing days
First Fall Frost December 3

Solano County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Start indoors: Dec 14 Transplant: Feb 1 🍅 Harvest: Jun 7 – Aug 16
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Dec 29 Transplant: Feb 16 🍅 Harvest: Jun 22 – Aug 31
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Jan 30 Transplant: Mar 20 🍅 Harvest: Jul 24 – Oct 2

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 Solano County

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

Soil pH

Your soil pH (6.8โ€“7.3) is within Jicama's preferred range (6.0โ€“7.5).

Soil Texture

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

Drainage

Drainage is adequate for Jicama.

Organic Matter

Organic matter is moderate (2.6%). 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
0.6″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,325 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 8.9" 0" โ„๏ธ Dormant
Feb 4.3" 8.4" 0" โœ… Rainfall sufficient
Mar 4.3" 6.6" 0" โœ… Rainfall sufficient
Apr 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
May 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Jun 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.4" 3.9" ๐Ÿšฟ Regular watering
Oct 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Nov 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Dec 4.3" 7.1" 0" โœ… Rainfall sufficient

Water needs are for active growing months only (Febโ€“Dec in Solano County). Supplement amounts are based on average rainfall โ€” 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" 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.

Jicama needs ~3,188 GDD — county provides 6,332 GDD Excellent fit

Jicama Planting Timeline โ€” Solano County, CA

Jicama Planting Calendar

Activity When Date Range
Start Indoors December 29 Dec 29 โ€“ Jan 12
Transplant Outdoors February 16 Feb 16 โ€“ Mar 2
Direct Sow February 9 Feb 9 โ€“ Mar 2
Harvest June 22 Jun 22 โ€“ Aug 31

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

297 days in Solano County

Growing Tips for Jicama in Solano County

Direct sow Jicama outdoors after February 09 in Solano 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 Solano County, CA?

Solano County is in Zone 9a with an average last frost of February 9. Plan your Jicama planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Solano County, CA?

Solano County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Solano County gardeners in Zone 9a 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 Solano County, CA. Local conditions may vary. Last updated: April 2026.