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When to plant Carrots in Castleton, IL

Castleton's spring Carrots window runs April 7 through April 28. time plantings around the expected last-frost window for best survival. A second sowing from August 3 to August 17 extends the harvest into fall.

When to Plant Carrots in Castleton, IL

Carrots
Stark County, Illinois Zone 5b June

What to do in June

A quick June briefing for Stark County, Illinois gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 21
Avg. first frost October 12
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Collect carrots at their peak

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Coming up in July — start thinking about
  • First harvests: 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.

Castleton, Illinois is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 12, giving you a growing season of approximately 174 days.

At an elevation of 1,071 feet, Stark County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Carrots to ensure they mature before fall.

Castleton, IL (Zone 5b) Moderate season
174 days
Last Spring Frost April 21
174 growing days
First Fall Frost October 12

Castleton Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Carrots Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Transplant: Apr 16 🍅 Harvest: Jun 18 – Jul 23
Recommended (50%) ✓ Fits season (76 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 23 – Jul 28
Safe Start (90%) ✓ Fits season (74 days to spare)
Transplant: May 8 🍅 Harvest: Jul 10 – Aug 14

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 Castleton

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

Soil pH

Your soil pH (6.0–6.9) overlaps with Carrots's range (6.0–6.8), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — Carrots will thrive.

How to Plant Carrots

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Carrots

3
successive plantings in your 174-day season

Sow every 6.9 weeks. Last sowing by Jul 24 to harvest before frost.

For a dedicated fall crop, sow by Aug 03.

Carrots Water Budget

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

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 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.5" 3.5" 0" ✅ Rainfall sufficient
May 3.5" 4.1" 0" ✅ Rainfall sufficient
Jun 3.5" 4.1" 0" ✅ Rainfall sufficient
Jul 3.5" 3.5" 0" ✅ Rainfall sufficient
Aug 3.5" 3.3" 0.2" 💧 Light watering
Sep 3.5" 2.8" 0.7" 💧 Light watering
Oct 3.5" 2.9" 0.6" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Stark 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 ~910 GDD — county provides 2,262 GDD Excellent fit

Carrots Planting Timeline — Castleton, IL

Carrots Planting Calendar

Activity When Date Range
Direct Sow April 7 Apr 7 – Apr 28
Harvest June 9 Jun 9 – Jul 14
Fall Sowing August 3 Aug 3 – Aug 17

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

174 days in Stark County

Growing Tips for Carrots in Castleton

Direct sow Carrots outdoors after April 21 in Stark County when soil has warmed and frost danger has passed.

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.

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.

When should I plant Carrots in Castleton, IL?

In Castleton, IL, plant Carrots after the last frost (around April 21) and before the first frost (around October 12). Best results when soil holds above 50°F.

What growing zone is Castleton, IL for Carrots?

Castleton sits in USDA Zone 5b. Carrots grows reliably in zones 3a through 10b, so it's a good fit here.

Can Carrots grow in Castleton's climate?

Yes — Carrots grows well in Castleton's temperate climate. Castleton averages a 174-day frost-free season, with last frost around April 21 and first frost around October 12.

🌱

Your Stark County Garden Planner — Free

A 22-page printable planner built for Stark County (Zone 5b). 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 Stark County, IL. Local conditions may vary. Last updated: June 2026.