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When to Plant Microgreens in Marion County, AR

Marion County, Arkansas Zone 7b May

This month in Marion County, Arkansas

Welcome to May in Zone 7b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 5
Avg. first frost October 27
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 13.9 hrs
  1. Indoor seed-starting week for microgreens

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. It's harvest week for microgreens

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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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.

Marion County, Arkansas is in USDA Zone 7b. The average last spring frost is April 5 and the first fall frost is October 27, giving you a growing season of approximately 205 days.

At an elevation of 546 feet, Marion County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Microgreens during the growing season.

Marion County, AR (Zone 7b) Long season
205 days
Last Spring Frost April 5
205 growing days
First Fall Frost October 27

Marion County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (171 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: Apr 4 – May 2
Recommended (50%) ✓ Fits season (170 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: Apr 12 – May 10
Safe Start (90%) ✓ Fits season (171 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Apr 28 – May 26

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 Marion County

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

Soil pH

Your soil pH (5.5–6.5) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Marion 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 (3.1%). 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

40
successive plantings in your 205-day season

Sow every 0.7 weeks. Last sowing by Oct 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

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

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 4.1" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 4.8" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 3.5" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Marion 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 ~224 GDD — county provides 3,280 GDD Excellent fit

Microgreens Planting Timeline — Marion County, AR

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 22 Mar 22 – Apr 12
Harvest April 12 Apr 12 – May 10
Fall Sowing August 18 Aug 18 – Sep 1

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors 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 · Natural rainfall sufficient

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

205 days in Marion County

Growing Tips for Microgreens in Marion County

Direct sow Microgreens outdoors after April 05 in Marion County when soil has warmed and frost danger has passed.

Your generous 205.0-day season in Marion 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 Marion County, AR?

Marion County is in Zone 7b with an average last frost of April 5. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marion County, AR?

Marion County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is April 5 and first fall frost is October 27.

🌱

Your Marion County Garden Planner — Free

A 24-page printable planner built for Marion 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 Marion County, AR. 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.