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When to Plant Broccoli Rabe in Glenn County, CA

Glenn County, California Zone 9b May

May in Glenn County, California — your action list

Each item below is timed to Glenn County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 6
Avg. first frost November 28
Soil temp (4") 75°F
Watering Critical
Pest pressure High
Daylight 14.2 hrs
  1. Harvest broccoli rabe as they ripen

    If you can't use it all right away, check the food-preservation section of your planner.

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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.

Glenn County, California is in USDA Zone 9b. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.

At an elevation of 270 feet, Glenn County receives approximately 27.1 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Broccoli Rabe during the growing season.

Glenn County, CA (Zone 9b) Long season
267 days
Last Spring Frost March 6
267 growing days
First Fall Frost November 28

Glenn County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (193 days to spare)
Start indoors: Jan 26 Transplant: Feb 23 🍅 Harvest: Apr 6 – May 11
Recommended (50%) ✓ Fits season (190 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🍅 Harvest: Apr 17 – May 22
Safe Start (90%) ✓ Fits season (168 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: May 30 – Jul 4

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 Glenn County

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

Soil pH

Your soil pH (6.5–7.9) overlaps with Broccoli Rabe's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Glenn County is excellent for Broccoli Rabe — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). 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 267-day season

Sow every 4.6 weeks. Last sowing by Sep 29 to harvest before frost.

For a dedicated fall crop, sow by Oct 03.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.4″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,066 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 5.6" 0" ❄️ Dormant
Feb 5.3" 0" ❄️ Dormant
Mar 3.5" 4.4" 0" ✅ Rainfall sufficient
Apr 3.5" 2.5" 1" 💧 Light watering
May 3.5" 0.7" 2.8" 🚿 Regular watering
Jun 3.5" 0.1" 3.4" 🚿 Regular watering
Jul 3.5" 0" 3.5" 🚿 Regular watering
Aug 3.5" 0" 3.5" 🚿 Regular watering
Sep 3.5" 0.3" 3.2" 🚿 Regular watering
Oct 3.5" 1.3" 2.2" 🚿 Regular watering
Nov 3.5" 2.5" 1" 💧 Light watering
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Glenn 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 ~800 GDD — county provides 4,272 GDD Excellent fit

Broccoli Rabe Planting Timeline — Glenn County, CA

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors March 6 Mar 6 – Mar 20
Direct Sow February 13 Feb 13 – Mar 6
Harvest April 17 Apr 17 – May 22
Fall Sowing October 3 Oct 3 – Oct 17

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
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 · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

267 days in Glenn County

Growing Tips for Broccoli Rabe in Glenn County

Direct sow Broccoli Rabe outdoors after March 06 in Glenn County when soil has warmed and frost danger has passed.

Your generous 267.0-day season in Glenn 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 Glenn County, CA?

Glenn County is in Zone 9b with an average last frost of March 6. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Glenn County, CA?

Glenn County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 6 and first fall frost is November 28.

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A 24-page printable planner built for Glenn 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 Glenn 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.