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When to Plant Broccoli Rabe in Kings County, CA

Kings County, California Zone 9a May

What to do in May

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

Avg. last frost February 14
Avg. first frost December 2
Soil temp (4") 72°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs
  1. Basket week: broccoli rabe

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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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.

Kings County, California is in USDA Zone 9a. The average last spring frost is February 14 and the first fall frost is December 2, giving you a growing season of approximately 291 days.

At an elevation of 2,065 feet, Kings County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Broccoli Rabe may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Broccoli Rabe successfully. Mulch heavily to conserve soil moisture.

Kings County, CA (Zone 9a) Year-round
291 days
Last Spring Frost February 14
291 growing days
First Fall Frost December 2

Kings County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (220 days to spare)
Start indoors: Jan 3 Transplant: Jan 31 🍅 Harvest: Mar 14 – Apr 18
Recommended (50%) ✓ Fits season (214 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🍅 Harvest: Mar 28 – May 2
Safe Start (90%) ✓ Fits season (212 days to spare)
Start indoors: Feb 8 Transplant: Mar 8 🍅 Harvest: Apr 19 – May 24

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 Kings County

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

Soil pH

Your soil pH (6.5–7.4) is within Broccoli Rabe's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). 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 291-day season

Sow every 4.6 weeks. Last sowing by Oct 03 to harvest before frost.

For a dedicated fall crop, sow by Oct 07.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.3″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,652 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 3.6" 0" ❄️ Dormant
Feb 3.5" 4" 0" ✅ Rainfall sufficient
Mar 3.5" 3.2" 0.3" 💧 Light watering
Apr 3.5" 1.4" 2.1" 🚿 Regular watering
May 3.5" 0.5" 3" 🚿 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" 0.2" 3.3" 🚿 Regular watering
Oct 3.5" 0.7" 2.8" 🚿 Regular watering
Nov 3.5" 1.9" 1.6" 💧 Light watering
Dec 3.5" 3.2" 0.3" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Kings 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 ~1,325 GDD — county provides 7,738 GDD Excellent fit

Broccoli Rabe Planting Timeline — Kings County, CA

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors February 14 Feb 14 – Feb 28
Direct Sow January 24 Jan 24 – Feb 14
Harvest March 28 Mar 28 – May 2
Fall Sowing October 7 Oct 7 – Oct 21

Plant 1" deep · 15" apart · Rows 24" 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

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: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

291 days in Kings County

Growing Tips for Broccoli Rabe in Kings County

Direct sow Broccoli Rabe outdoors after February 14 in Kings County when soil has warmed and frost danger has passed.

With summer highs reaching 102°F in Kings County, provide afternoon shade for Broccoli Rabe and water deeply in the morning.

Your generous 292.0-day season in Kings 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 Kings County, CA?

Kings County is in Zone 9a with an average last frost of February 14. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kings County, CA?

Kings County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 14 and first fall frost is December 2.

🌱

Your Kings County Garden Planner — Free

A 24-page printable planner built for Kings County (Zone 9a). 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 Kings 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.