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When to Plant Broccoli Rabe in Marin County, CA

Marin County, California Zone 9b May

Top priorities for Marin County, California gardeners in May

Here's what deserves your attention in Marin County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost February 26
Avg. first frost November 26
Soil temp (4") 79°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Start harvesting broccoli rabe

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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Broccoli rabe (rapini) is a brassica grown for its slightly bitter, nutty-flavored florets, leaves, and stems. It is a staple in Italian cooking.

Marin County, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 302 feet, Marin County receives approximately 36 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 81°F, so choose short-season varieties of Broccoli Rabe to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Broccoli Rabe will need more frequent watering and organic matter to retain nutrients.

Marin County, CA (Zone 9b) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Marin County Soil Profile

Soil Type

Sandy Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (208 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Mar 24 – Apr 28
Recommended (50%) ✓ Fits season (196 days to spare)
Start indoors: Jan 29 Transplant: Feb 26 🍅 Harvest: Apr 9 – May 14
Safe Start (90%) ✓ Fits season (182 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: May 14 – Jun 18

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 Marin County

How your county's soil matches Broccoli Rabe's growing requirements.

Soil pH

Your soil pH (6.0–6.9) is within Broccoli Rabe's preferred range (6.0–7.5).

Soil Texture

Sandy soil in Marin County warms quickly in spring but drains fast. Broccoli Rabe will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Broccoli Rabe.

How to Plant Broccoli Rabe

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Broccoli Rabe

8
successive plantings in your 273-day season

Sow every 4.6 weeks. Last sowing by Sep 27 to harvest before frost.

For a dedicated fall crop, sow by Oct 01.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.6″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 726 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Broccoli Rabe

Broccoli Rabe needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Broccoli Rabe Needs Rainfall You Supplement Action
Jan 7.2" 0" ❄️ Dormant
Feb 3.5" 6.5" 0" ✅ Rainfall sufficient
Mar 3.5" 6.2" 0" ✅ Rainfall sufficient
Apr 3.5" 2.7" 0.8" 💧 Light watering
May 3.5" 1" 2.5" 🚿 Regular watering
Jun 3.5" 0.2" 3.3" 🚿 Regular watering
Jul 3.5" 0" 3.5" 🚿 Regular watering
Aug 3.5" 0" 3.5" 🚿 Regular watering
Sep 3.5" 0.4" 3.1" 🚿 Regular watering
Oct 3.5" 1.4" 2.1" 🚿 Regular watering
Nov 3.5" 3.5" 0" ✅ Rainfall sufficient
Dec 6.9" 0" ❄️ Dormant

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

Broccoli Rabe 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.

Broccoli Rabe needs ~538 GDD — county provides 2,945 GDD Excellent fit

Broccoli Rabe Planting Timeline — Marin County, CA

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors February 26 Feb 26 – Mar 12
Direct Sow February 5 Feb 5 – Feb 26
Harvest April 9 Apr 9 – May 14
Fall Sowing October 1 Oct 1 – Oct 15

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

273 days in Marin County

Growing Tips for Broccoli Rabe in Marin County

Direct sow Broccoli Rabe outdoors after February 26 in Marin County when soil has warmed and frost danger has passed.

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

Your generous 274.0-day season in Marin County allows multiple plantings of Broccoli Rabe. Sow every 20.0 days for continuous harvest.

Common pests for Broccoli Rabe in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Harvest when small yellow flower buds first appear but before they open. Cut the main shoot first to encourage side shoots.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Broccoli Rabe in Marin County, CA?

Marin County is in Zone 9b with an average last frost of February 26. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marin County, CA?

Marin County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 26 and first fall frost is November 26.

🌱

Your Marin County Garden Planner — Free

A 24-page printable planner built for Marin 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 Marin 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.