When to Plant Radish in Phillips County, CO
Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.
Phillips County, Colorado is in USDA Zone 5a. The average last spring frost is May 4 and the first fall frost is October 7, giving you a growing season of approximately 156 days.
At an elevation of 5,494 feet, Phillips County receives approximately 21.1 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Radish during the growing season.
Phillips County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.8
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.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Radish Planting Timeline — Phillips County, CO
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 20 | Apr 20 – May 11 |
| Fall Sowing | July 29 | Jul 29 – Aug 12 |
| Harvest | May 18 | May 18 – Jun 8 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow Harvest |
| June | Harvest |
| July | Fall Sowing |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
22–35 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
156 days
Growing Tips for Phillips County
Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Radish in Other Locations
Frequently Asked Questions
When should I plant Radish in Phillips County, CO?
Phillips County is in Zone 5a with an average last frost of May 4. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Phillips County, CO?
Phillips County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 4 and first fall frost is October 7.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Phillips County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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