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When to Plant Carrots in Jackson County, CO

Jackson County, Colorado Zone 4b May

Top priorities for Jackson County, Colorado gardeners in May

May is a pivotal month for Jackson County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost June 13
Avg. first frost September 4
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.3 hrs
June prep starts now
  • Direct-sowing: carrots
  • Fall sowing: carrots

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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.

Jackson County, Colorado is in USDA Zone 4b. The average last spring frost is June 13 and the first fall frost is September 4, giving you a growing season of approximately 83 days.

At an elevation of 5,388 feet, Jackson County receives approximately 20.9 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Carrots to ensure they mature before fall.

Jackson County, CO (Zone 4b) Very short season
83 days
Last Spring Frost June 13
83 growing days
First Fall Frost September 4
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Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 8 🍅 Harvest: Aug 10 – Sep 14
Recommended (50%) ✗ May not fit
Transplant: Jun 13 🍅 Harvest: Aug 15 – Sep 19
Safe Start (90%) ✗ May not fit
Transplant: Jun 25 🍅 Harvest: Aug 27 – Oct 1

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 Jackson County

How your county's soil matches Carrots's growing requirements.

Soil pH

Your soil pH (6.6–8.1) is more alkaline than Carrots prefers (6.0–6.8). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Jackson County is excellent for Carrots — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Carrots.

How to Plant Carrots

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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 1.6" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.3" 0" ❄️ Dormant
May 2.2" 0" ❄️ Dormant
Jun 3.5" 1.7" 1.8" 🚿 Regular watering
Jul 3.5" 1.7" 1.8" 🚿 Regular watering
Aug 3.5" 2.5" 1" 💧 Light watering
Sep 3.5" 1.5" 2" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Jackson 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 needs ~700 GDD — county provides 830 GDD Good fit

Carrots Planting Timeline — Jackson County, CO

Carrots Planting Calendar

Activity When Date Range
Direct Sow June 6 Jun 6 – Jun 27
Harvest August 8 Aug 8 – Sep 12
Fall Sowing June 12 Jun 12 – Jun 26

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Direct Sow Fall Sowing
July
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–6.8 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

83 days in Jackson County

Growing Tips for Carrots in Jackson County

Direct sow Carrots outdoors after June 13 in Jackson County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Jackson 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 Jackson County

Fast-maturing varieties for your season

Adelaide (50d) Mokum (54d) Nelson (56d)

Companion Planting

Good Companions

Avoid Planting Near

  • Dill
  • Parsnip

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Carrots Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Replant roots for 2nd year flowers. Harvest umbels when brown.
Storage Store airtight; viable 3 years at 35°F, under 50% humidity.

Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial — requires two seasons.

Frequently Asked Questions

When should I plant Carrots in Jackson County, CO?

Jackson County is in Zone 4b with an average last frost of June 13. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, CO?

Jackson County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 13 and first fall frost is September 4.

🌱

Your Jackson County Garden Planner — Free

A 24-page printable planner built for Jackson County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jackson County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.