When to Plant Broccoli Rabe in Lewis County, ID
Lewis County, Idaho gardeners: here's your May plan
Your Lewis County, Idaho garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Get broccoli rabe in the ground
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Seed broccoli rabe outdoors
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
June prep starts now
- Starting indoors: 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.
Lewis County, Idaho is in USDA Zone 6b. The average last spring frost is May 20 and the first fall frost is September 23, giving you a growing season of approximately 126 days.
At an elevation of 4,861 feet, Lewis County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Broccoli Rabe during the growing season. With low rainfall, drip irrigation is essential for growing Broccoli Rabe successfully. Mulch heavily to conserve soil moisture.
Lewis County Soil Profile
Soil Type
Loam
Soil pH
6.7-8
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 Lewis County
How your county's soil matches Broccoli Rabe's growing requirements.
Soil pH
Your soil pH (6.7–8.0) overlaps with Broccoli Rabe's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Lewis County is excellent for Broccoli Rabe — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Broccoli Rabe.
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 Jul 25 to harvest before frost.
For a dedicated fall crop, sow by Jul 15.
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" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | 3.5" | 1.7" | 1.8" | 🚿 Regular watering |
| Jun | 3.5" | 0.8" | 2.7" | 🚿 Regular watering |
| Jul | 3.5" | 1.2" | 2.3" | 🚿 Regular watering |
| Aug | 3.5" | 1.4" | 2.1" | 🚿 Regular watering |
| Sep | 3.5" | 1.2" | 2.3" | 🚿 Regular watering |
| Oct | — | 1.3" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lewis 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 — Lewis County, ID
Broccoli Rabe Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 15 | Apr 15 – Apr 29 |
| Transplant Outdoors | May 20 | May 20 – Jun 3 |
| Direct Sow | May 6 | May 6 – May 27 |
| Harvest | July 1 | Jul 1 – Aug 5 |
| Fall Sowing | July 15 | Jul 15 – Jul 29 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| 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: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
126 days in Lewis County
Growing Tips for Broccoli Rabe in Lewis County
Direct sow Broccoli Rabe outdoors after May 20 in Lewis 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 Lewis County, ID?
Lewis County is in Zone 6b with an average last frost of May 20. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lewis County, ID?
Lewis County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 20 and first fall frost is September 23.
Your Lewis County Garden Planner — Free
A 24-page printable planner built for Lewis County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.