When to Plant Broccoli Rabe in St. Louis County, MN
What to do in May
Welcome to May in Zone 3b. These are the moves that will have the biggest impact on your growing season.
-
Sow broccoli rabe where they'll grow
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
To set up a strong June, finish these tasks
- Transplants going out: broccoli rabe
- Fall sowing: broccoli rabe
Broccoli rabe (rapini) is a brassica grown for its slightly bitter, nutty-flavored florets, leaves, and stems. It is a staple in Italian cooking.
St. Louis County, Minnesota is in USDA Zone 3b. The average last spring frost is June 2 and the first fall frost is September 10, giving you a growing season of approximately 100 days.
At an elevation of 531 feet, St. Louis County receives approximately 36.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 78°F, so choose short-season varieties of Broccoli Rabe to ensure they mature before fall.
St. Louis County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7
Drainage
Well Drained
Plant Planting Risk Windows
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 St. Louis County
How your county's soil matches Broccoli Rabe's growing requirements.
Soil pH
Your soil pH (6.0–7.0) is within Broccoli Rabe's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in St. Louis County is excellent for Broccoli Rabe — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Broccoli Rabe.
Organic Matter
Organic matter is excellent (4.0%) — Broccoli Rabe will thrive.
How to Plant Broccoli Rabe
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Broccoli Rabe
Sow every 4.6 weeks. Last sowing by Jul 12 to harvest before frost.
For a dedicated fall crop, sow by Jun 18.
Plant Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | — | 3.2" | 0" | ❄️ Dormant |
| May | — | 3.9" | 0" | ❄️ Dormant |
| Jun | 3.5" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.1" | 0.4" | 💧 Light watering |
| Oct | — | 2.8" | 0" | ❄️ Dormant |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in St. Louis 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 Planting Timeline — St. Louis County, MN
Broccoli Rabe Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 21 | Apr 21 – May 5 |
| Transplant Outdoors | June 2 | Jun 2 – Jun 16 |
| Direct Sow | May 26 | May 26 – Jun 16 |
| Harvest | July 14 | Jul 14 – Aug 18 |
| Fall Sowing | June 18 | Jun 18 – Jul 2 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Direct Sow |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| 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: ideal
🗺️ USDA Zone
Zone 3b
📆 Growing Season
100 days in St. Louis County
Growing Tips for Broccoli Rabe in St. Louis County
Direct sow Broccoli Rabe outdoors after June 02 in St. Louis County when soil has warmed and frost danger has passed.
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
Check more plant combinations with our Companion Planting Checker →
Broccoli Rabe in Other Locations
Frequently Asked Questions
When should I plant Broccoli Rabe in St. Louis County, MN?
St. Louis County is in Zone 3b with an average last frost of June 2. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Louis County, MN?
St. Louis County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is June 2 and first fall frost is September 10.
Your St. Louis County Garden Planner — Free
A 24-page printable planner built for St. Louis County (Zone 3b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.