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When to Plant Carrots in Harmon County, OK

Harmon County, Oklahoma Zone 7b May

May to-do list for Harmon County, Oklahoma

Your garden in Harmon County, Oklahoma is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost March 31
Avg. first frost November 5
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Collect carrots at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

June will be here before you know it — start on
  • 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.

Harmon County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 5, giving you a growing season of approximately 219 days.

At an elevation of 993 feet, Harmon County receives approximately 34.4 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Carrots during the growing season.

Harmon County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 31
219 growing days
First Fall Frost November 5
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Harmon County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (121 days to spare)
Transplant: Mar 23 🍅 Harvest: May 25 – Jun 29
Recommended (50%) ✓ Fits season (121 days to spare)
Transplant: Mar 31 🍅 Harvest: Jun 2 – Jul 7
Safe Start (90%) ✓ Fits season (121 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 22

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 Harmon County

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

Soil pH

Your soil pH (6.5–7.5) is more alkaline than Carrots prefers (6.0–6.8). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — 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

4
successive plantings in your 219-day season

Sow every 6.9 weeks. Last sowing by Aug 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 328 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 3.5" 2.3" 1.2" 💧 Light watering
Apr 3.5" 3.7" 0" ✅ Rainfall sufficient
May 3.5" 5.1" 0" ✅ Rainfall sufficient
Jun 3.5" 5" 0" ✅ Rainfall sufficient
Jul 3.5" 4.1" 0" ✅ Rainfall sufficient
Aug 3.5" 4.8" 0" ✅ Rainfall sufficient
Sep 3.5" 3" 0.5" 💧 Light watering
Oct 3.5" 2" 1.5" 💧 Light watering
Nov 3.5" 1.3" 2.2" 🚿 Regular watering
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Harmon 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 ~1,278 GDD — county provides 3,996 GDD Excellent fit

Carrots Planting Timeline — Harmon County, OK

Carrots Planting Calendar

Activity When Date Range
Direct Sow March 17 Mar 17 – Apr 7
Harvest May 19 May 19 – Jun 23
Fall Sowing August 27 Aug 27 – Sep 10

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

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April Direct Sow
May Harvest
June Harvest
July
August Fall Sowing
September Fall Sowing
October
November
December
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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 7b

📆 Growing Season

219 days in Harmon County

Growing Tips for Carrots in Harmon County

Direct sow Carrots outdoors after March 31 in Harmon 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.

Frequently Asked Questions

When should I plant Carrots in Harmon County, OK?

Harmon County is in Zone 7b with an average last frost of March 31. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harmon County, OK?

Harmon County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 5.

🌱

Your Harmon County Garden Planner — Free

A 24-page printable planner built for Harmon County (Zone 7b). 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 Harmon County, OK. 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.