When to Plant Broccoli Rabe in Monona County, IA
Your May game plan for Monona County, Iowa
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Indoor seed-starting week for broccoli rabe
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
A few tasks this May that'll pay off in June
- First harvests: 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.
Monona County, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 10, giving you a growing season of approximately 167 days.
At an elevation of 732 feet, Monona County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Broccoli Rabe to ensure they mature before fall.
Monona County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-7.1
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 Monona County
How your county's soil matches Broccoli Rabe's growing requirements.
Soil pH
Your soil pH (5.7–7.1) overlaps with Broccoli Rabe's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Monona 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 (4.4%) — Broccoli Rabe will thrive.
How to Plant Broccoli Rabe
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Broccoli Rabe
Sow every 4.6 weeks. Last sowing by Aug 11 to harvest before frost.
For a dedicated fall crop, sow by Aug 01.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 3.5" | 3" | 0.5" | 💧 Light watering |
| May | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| Oct | 3.5" | 3" | 0.5" | 💧 Light watering |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Monona 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 — Monona County, IA
Broccoli Rabe Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | April 26 | Apr 26 – May 10 |
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | June 7 | Jun 7 – Jul 12 |
| Fall Sowing | August 1 | Aug 1 – Aug 15 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
167 days in Monona County
Growing Tips for Broccoli Rabe in Monona County
Direct sow Broccoli Rabe outdoors after April 26 in Monona County when soil has warmed and frost danger has passed.
Your generous 167.0-day season in Monona 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
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Broccoli Rabe in Other Locations
Frequently Asked Questions
When should I plant Broccoli Rabe in Monona County, IA?
Monona County is in Zone 5a with an average last frost of April 26. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.
What planting zone is Monona County, IA?
Monona County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 26 and first fall frost is October 10.
Your Monona County Garden Planner — Free
A 24-page printable planner built for Monona County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.