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When to plant Arugula in Ripon, CA

Aim to plant Arugula in Ripon on or after January 14; the window stays open through February 4. Ripon's 306-day frost-free season gives you plenty of room for a spring and fall cycle. A second sowing from October 11 to October 25 extends the harvest into fall.

When to Plant Arugula in Ripon, CA

Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.

Ripon, California is in USDA Zone 9b. The average last spring frost is February 4 and the first fall frost is December 6, giving you a growing season of approximately 305 days.

At an elevation of 220 feet, San Joaquin County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Arugula during the growing season. With low rainfall, drip irrigation is essential for growing Arugula successfully. Mulch heavily to conserve soil moisture.

Ripon, CA (Zone 9b) Year-round
305 days
Last Spring Frost February 4
305 growing days
First Fall Frost December 6

Ripon Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Monthly Watering Guide for Arugula

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

Month Arugula Needs Rainfall You Supplement Action
Jan 2.9" 0" ❄️ Dormant
Feb 4.3" 3.1" 1.2" 💧 Light watering
Mar 4.3" 2.6" 1.7" 💧 Light watering
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 0.4" 3.9" 🚿 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" 0.7" 3.6" 🚿 Regular watering
Nov 4.3" 1.3" 3" 🚿 Regular watering
Dec 4.3" 2.6" 1.7" 💧 Light watering

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

Arugula Planting Timeline — Ripon, CA

Arugula Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 – Jan 21
Transplant Outdoors February 4 Feb 4 – Feb 18
Direct Sow January 14 Jan 14 – Feb 4
Harvest March 11 Mar 11 – May 13
Fall Sowing October 11 Oct 11 – Oct 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

305 days in San Joaquin County

Growing Tips for Ripon

Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

When should I plant Arugula in Ripon, CA?

In Ripon, CA, plant Arugula after the last frost (around February 4) and before the first frost (around December 6). Best results when soil holds above 50°F.

What growing zone is Ripon, CA for Arugula?

Ripon sits in USDA Zone 9b. Arugula grows reliably in zones 3a through 11b, so it's a good fit here.

Can Arugula grow in Ripon's climate?

Yes — Arugula grows well in Ripon's temperate climate. Ripon averages a 306-day frost-free season, with last frost around February 4 and first frost around December 6.

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Your San Joaquin County Garden Planner — Free

A 22-page printable planner built for San Joaquin County (Zone 9b). 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 Joaquin County, CA. Local conditions may vary. Last updated: June 2026.