When to Plant Carrots in San Juan County, CO
Your May gardening checklist
Your San Juan County, Colorado garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
June prep starts now
- Direct-sowing: carrots
- Fall sowing: carrots
Carrots are a popular root vegetable available in orange, purple, white, and yellow varieties. They are rich in beta-carotene and have a sweet, earthy flavor.
San Juan County, Colorado is in USDA Zone 5a. The average last spring frost is June 18 and the first fall frost is September 8, giving you a growing season of approximately 82 days.
At an elevation of 7,539 feet, San Juan County receives approximately 20.1 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Carrots to ensure they mature before fall.
San Juan County Soil Profile
Soil Type
Loam
Soil pH
6.3-8
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 San Juan County
How your county's soil matches Carrots's growing requirements.
Soil pH
Your soil pH (6.3–8.0) is more alkaline than Carrots prefers (6.0–6.8). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in San Juan County is excellent for Carrots — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Carrots.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Carrots.
How to Plant Carrots
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Carrots
Carrots 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 | Carrots Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.6" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | — | 2.4" | 0" | ❄️ Dormant |
| Jun | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
| Jul | 3.5" | 2" | 1.5" | 💧 Light watering |
| Aug | 3.5" | 2.3" | 1.2" | 💧 Light watering |
| Sep | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in San Juan County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Carrots 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.
Carrots Planting Timeline — San Juan County, CO
Carrots Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | June 4 | Jun 4 – Jun 25 |
| Harvest | August 6 | Aug 6 – Sep 10 |
| Fall Sowing | June 30 | Jun 30 – Jul 14 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Direct Sow Fall Sowing |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–6.8 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
82 days in San Juan County
Growing Tips for Carrots in San Juan County
Direct sow Carrots outdoors after June 18 in San Juan County when soil has warmed and frost danger has passed.
Your 82.0-day growing season in San Juan County is tight for Carrots (60.0-80.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Carrots in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly in loose, stone-free soil for straight roots. Keep soil moist until germination which can take 2-3 weeks. Thin seedlings to 2 inches apart.
Recommended Carrots Varieties for San Juan County
Fast-maturing varieties for your season
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial — requires two seasons.
Carrots in Other Locations
Frequently Asked Questions
When should I plant Carrots in San Juan County, CO?
San Juan County is in Zone 5a with an average last frost of June 18. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Juan County, CO?
San Juan County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 18 and first fall frost is September 8.
Your San Juan County Garden Planner — Free
A 24-page printable planner built for San Juan 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.