When to Plant Broccoli in Deer Lodge County, MT
Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.
Deer Lodge County, Montana is in USDA Zone 4a. The average last spring frost is June 15 and the first fall frost is September 7, giving you a growing season of approximately 84 days.
At an elevation of 6,928 feet, Deer Lodge County receives approximately 16.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Broccoli to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Broccoli successfully. Mulch heavily to conserve soil moisture.
Deer Lodge County Soil Profile
Soil Type
Loam
Soil pH
6.6-8.2
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 Deer Lodge County
How your county's soil matches Broccoli's growing requirements.
Soil pH
Your soil pH (6.6–8.2) is more alkaline than Broccoli prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Deer Lodge County is excellent for Broccoli — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Broccoli.
How to Plant Broccoli
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
How Much Broccoli to Grow
For a family of 4, plant approximately 12 broccoli plants in about 30 sq ft. In Deer Lodge County's 84-day season, you'll have plenty of time for a full harvest. Plan your garden layout →
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Broccoli
Broccoli needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Broccoli Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 1.4" | 0" | ❄️ Dormant |
| Apr | — | 1.9" | 0" | ❄️ Dormant |
| May | — | 1.9" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Jul | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Aug | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.1" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Deer Lodge County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Broccoli 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 Planting Timeline — Deer Lodge County, MT
Broccoli Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 4 | May 4 – May 18 |
| Transplant Outdoors | June 15 | Jun 15 – Jun 29 |
| Direct Sow | June 8 | Jun 8 – Jun 29 |
| Harvest | August 17 | Aug 17 – Sep 28 |
| Fall Sowing | June 15 | Jun 15 – Jun 29 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 4a
📆 Growing Season
84 days in Deer Lodge County
Growing Tips for Broccoli in Deer Lodge County
Direct sow Broccoli outdoors after June 15 in Deer Lodge County when soil has warmed and frost danger has passed.
Your 84.0-day growing season in Deer Lodge County is tight for Broccoli (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Broccoli in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Deer Lodge County receives only 17" of rain annually. Broccoli needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.
Broccoli in Other Locations
Frequently Asked Questions
When should I plant Broccoli in Deer Lodge County, MT?
Deer Lodge County is in Zone 4a with an average last frost of June 15. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.
What planting zone is Deer Lodge County, MT?
Deer Lodge County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is June 15 and first fall frost is September 7.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Deer Lodge County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.