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When to Plant Microgreens in Marshall County, IN

Marshall County, Indiana Zone 6a May

Your May planting checklist for Marshall County, Indiana

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 26
Avg. first frost October 18
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Get microgreens seeds going inside

    These need a head start before your last frost (April 26). Sow into cells now so you're ready to transplant in a few weeks.

  2. Basket week: microgreens

    If you can't use it all right away, check the food-preservation section of your planner.

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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.

Marshall County, Indiana is in USDA Zone 6a. The average last spring frost is April 26 and the first fall frost is October 18, giving you a growing season of approximately 175 days.

At an elevation of 1,140 feet, Marshall County receives approximately 34.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Microgreens to ensure they mature before fall.

Marshall County, IN (Zone 6a) Moderate season
175 days
Last Spring Frost April 26
175 growing days
First Fall Frost October 18

Marshall County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (141 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🍅 Harvest: Apr 27 – May 25
Recommended (50%) ✓ Fits season (140 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: May 3 – May 31
Safe Start (90%) ✓ Fits season (137 days to spare)
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: May 19 – Jun 16

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 Marshall County

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

Soil pH

Your soil pH (6.2–7.3) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is excellent (5.1%) — Microgreens will thrive.

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

34
successive plantings in your 175-day season

Sow every 0.7 weeks. Last sowing by Sep 27 to harvest before frost.

For a dedicated fall crop, sow by Aug 09.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 735 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 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Marshall 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 ~182 GDD — county provides 2,275 GDD Excellent fit

Microgreens Planting Timeline — Marshall County, IN

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors April 26 Apr 26 – May 10
Direct Sow April 12 Apr 12 – May 3
Harvest May 3 May 3 – May 31
Fall Sowing August 9 Aug 9 – Aug 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

175 days in Marshall County

Growing Tips for Microgreens in Marshall County

Direct sow Microgreens outdoors after April 26 in Marshall County when soil has warmed and frost danger has passed.

Your generous 175.0-day season in Marshall 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 Marshall County, IN?

Marshall County is in Zone 6a with an average last frost of April 26. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marshall County, IN?

Marshall County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 26 and first fall frost is October 18.

🌱

Your Marshall County Garden Planner — Free

A 24-page printable planner built for Marshall County (Zone 6a). 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 Marshall County, IN. 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.