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When to Plant Microgreens in Carter County, OK

Carter County, Oklahoma Zone 8a May

Your May game plan for Carter County, Oklahoma

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

Avg. last frost March 28
Avg. first frost November 2
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Begin indoor sowing: microgreens

    Label every cell. You will absolutely forget which is which otherwise.

  2. Bring in the microgreens

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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Microgreens are young seedlings of vegetables and herbs harvested at the cotyledon or first true leaf stage. They pack concentrated flavors and nutrients in a tiny package.

Carter County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 648 feet, Carter County receives approximately 34.2 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Microgreens during the growing season.

Carter County, OK (Zone 8a) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Carter County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (186 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: Mar 28 – Apr 25
Recommended (50%) ✓ Fits season (184 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: Apr 4 – May 2
Safe Start (90%) ✓ Fits season (185 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Apr 24 – May 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 Carter County

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

Soil pH

Your soil pH (6.4–7.5) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Microgreens.

How to Plant Microgreens

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

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

Succession Planting Microgreens

43
successive plantings in your 219-day season

Sow every 0.7 weeks. Last sowing by Oct 12 to harvest before frost.

For a dedicated fall crop, sow by Aug 24.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,507 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Microgreens

Microgreens needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Microgreens Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 4.3" 1.9" 2.4" 🚿 Regular watering
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 5.8" 0" ✅ Rainfall sufficient
Jun 4.3" 6" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.3" 2" 💧 Light watering
Nov 4.3" 1.2" 3.1" 🚿 Regular watering
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Carter County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Microgreens 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.

Microgreens needs ~276 GDD — county provides 4,325 GDD Excellent fit

Microgreens Planting Timeline — Carter County, OK

Microgreens Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors March 28 Mar 28 – Apr 11
Direct Sow March 14 Mar 14 – Apr 4
Harvest April 4 Apr 4 – May 2
Fall Sowing August 24 Aug 24 – Sep 7

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

219 days in Carter County

Growing Tips for Microgreens in Carter County

Direct sow Microgreens outdoors after March 28 in Carter County when soil has warmed and frost danger has passed.

Your generous 219.0-day season in Carter County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

General growing tips

Sow seeds densely on shallow trays of moist growing medium. Cover until germination, then provide light. Harvest with scissors when 1-3 inches tall. Grow year-round indoors.

Frequently Asked Questions

When should I plant Microgreens in Carter County, OK?

Carter County is in Zone 8a with an average last frost of March 28. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carter County, OK?

Carter County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 28 and first fall frost is November 2.

🌱

Your Carter County Garden Planner — Free

A 24-page printable planner built for Carter County (Zone 8a). 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 Carter 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.