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When to Plant Broccoli Rabe in Polk County, OR

Polk County, Oregon Zone 8b May

Your May gardening checklist

We've pulled the most time-sensitive tasks for Polk County, Oregon this May and put them front and centre. Tackle them in order.

Avg. last frost April 10
Avg. first frost October 31
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
  1. Start broccoli rabe under lights

    These need a head start before your last frost (April 10). Sow into cells now so you're ready to transplant in a few weeks.

  2. It's harvest week for broccoli rabe

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

To set up a strong June, finish these tasks
  • First harvests: broccoli rabe

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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.

Polk County, Oregon is in USDA Zone 8b. The average last spring frost is April 10 and the first fall frost is October 31, giving you a growing season of approximately 204 days.

At an elevation of 331 feet, Polk County receives approximately 54.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Broccoli Rabe to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Broccoli Rabe root diseases.

Polk County, OR (Zone 8b) Long season
204 days
Last Spring Frost April 10
204 growing days
First Fall Frost October 31

Polk County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (138 days to spare)
Start indoors: Feb 17 Transplant: Mar 24 🍅 Harvest: May 5 – Jun 9
Recommended (50%) ✓ Fits season (127 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 22 – Jun 26
Safe Start (90%) ✓ Fits season (133 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 13 – Jul 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 Polk County

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

Soil pH

Your soil pH (5.7–6.5) overlaps with Broccoli Rabe's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Broccoli Rabe will thrive.

How to Plant Broccoli Rabe

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Broccoli Rabe

6
successive plantings in your 204-day season

Sow every 4.6 weeks. Last sowing by Sep 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 22.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 8.7" 0" ❄️ Dormant
Feb 5.6" 0" ❄️ Dormant
Mar 5" 0" ❄️ Dormant
Apr 3.5" 4.2" 0" ✅ Rainfall sufficient
May 3.5" 3.5" 0" ✅ Rainfall sufficient
Jun 3.5" 2.4" 1.1" 💧 Light watering
Jul 3.5" 0.9" 2.6" 🚿 Regular watering
Aug 3.5" 1.1" 2.4" 🚿 Regular watering
Sep 3.5" 1.8" 1.7" 💧 Light watering
Oct 3.5" 4.5" 0" ✅ Rainfall sufficient
Nov 8.1" 0" ❄️ Dormant
Dec 8.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Polk 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 2,193 GDD Excellent fit

Broccoli Rabe Planting Timeline — Polk County, OR

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 27 Mar 27 – Apr 17
Harvest May 22 May 22 – Jun 26
Fall Sowing August 22 Aug 22 – Sep 5

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

204 days in Polk County

Growing Tips for Broccoli Rabe in Polk County

Direct sow Broccoli Rabe outdoors after April 10 in Polk County when soil has warmed and frost danger has passed.

Your generous 204.0-day season in Polk 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 Polk County, OR?

Polk County is in Zone 8b with an average last frost of April 10. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Polk County, OR?

Polk County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 10 and first fall frost is October 31.

🌱

Your Polk County Garden Planner — Free

A 24-page printable planner built for Polk County (Zone 8b). 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 Polk County, OR. 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.