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When to Plant Broccoli Rabe in Douglas County, KS

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

Douglas County, Kansas is in USDA Zone 6a. The average last spring frost is April 12 and the first fall frost is October 25, giving you a growing season of approximately 196 days.

At an elevation of 494 feet, Douglas County receives approximately 27.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Broccoli Rabe during the growing season.

Douglas County, KS (Zone 6a) Moderate season
196 days
Last Spring Frost April 12
196 growing days
First Fall Frost October 25

Douglas County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: May 18 – Jun 22
Recommended (50%) ✓ Fits season (119 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: May 24 – Jun 28
Safe Start (90%) ✓ Fits season (121 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jun 7 – Jul 12

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 Douglas County

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

Soil pH

Your soil pH (6.5โ€“7.6) overlaps with Broccoli Rabe's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Douglas County is excellent for Broccoli Rabe โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Broccoli Rabe.

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

5
successive plantings in your 196-day season

Sow every 4.6 weeks. Last sowing by Aug 26 to harvest before frost.

For a dedicated fall crop, sow by Aug 16.

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 432 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr 3.5" 2.7" 0.8" ๐Ÿ’ง Light watering
May 3.5" 4.3" 0" โœ… Rainfall sufficient
Jun 3.5" 4" 0" โœ… Rainfall sufficient
Jul 3.5" 3.9" 0" โœ… Rainfall sufficient
Aug 3.5" 3.6" 0" โœ… Rainfall sufficient
Sep 3.5" 2.4" 1.1" ๐Ÿ’ง Light watering
Oct 3.5" 1.7" 1.8" ๐Ÿšฟ Regular watering
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Douglas County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~875 GDD — county provides 3,430 GDD Excellent fit

Broccoli Rabe Planting Timeline โ€” Douglas County, KS

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 โ€“ Mar 22
Transplant Outdoors April 12 Apr 12 โ€“ Apr 26
Direct Sow March 29 Mar 29 โ€“ Apr 19
Harvest May 24 May 24 โ€“ Jun 28
Fall Sowing August 16 Aug 16 โ€“ Aug 30

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

196 days in Douglas County

Growing Tips for Broccoli Rabe in Douglas County

Direct sow Broccoli Rabe outdoors after April 12 in Douglas County when soil has warmed and frost danger has passed.

Your generous 196.0-day season in Douglas 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 Douglas County, KS?

Douglas County is in Zone 6a with an average last frost of April 12. Plan your Broccoli Rabe planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Douglas County, KS?

Douglas County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 12 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Douglas County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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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 Douglas County, KS. Local conditions may vary. Last updated: April 2026.