When to Plant Brussels Sprouts in Park County, CO
Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.
Park County, Colorado is in USDA Zone 4b. The average last spring frost is June 16 and the first fall frost is September 4, giving you a growing season of approximately 80 days.
At an elevation of 7,567 feet, Park County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Brussels Sprouts to ensure they mature before fall.
Park County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.6
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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Brussels Sprouts Planting Timeline — Park County, CO
Brussels Sprouts Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 5 | May 5 – May 19 |
| Transplant Outdoors | June 16 | Jun 16 – Jun 30 |
| Direct Sow | June 9 | Jun 9 – Jun 30 |
| Fall Sowing | June 12 | Jun 12 – Jun 26 |
| Harvest | September 15 | Sep 15 – Nov 10 |
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 | — |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–130 days
Soil pH
6 – 7.5
USDA Zone
Zone 4b
Growing Season
80 days
Growing Tips for Park County
Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Brussels Sprouts in Other Locations
Frequently Asked Questions
When should I plant Brussels Sprouts in Park County, CO?
Park County is in Zone 4b with an average last frost of June 16. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.
What planting zone is Park County, CO?
Park County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 16 and first fall frost is September 4.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Park County gardeners in Zone 4b 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.