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When to Plant Microgreens in Lucas County, IA

Lucas County, Iowa Zone 5b May

What to do in May

A quick May briefing for Lucas County, Iowa gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 21
Avg. first frost October 13
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Get microgreens seeds going inside

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

  2. Pick 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.

Lucas County, Iowa is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.

At an elevation of 638 feet, Lucas County receives approximately 41.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Microgreens during the growing season.

Lucas County, IA (Zone 5b) Moderate season
175 days
Last Spring Frost April 21
175 growing days
First Fall Frost October 13
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Lucas County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Apr 22 – May 20
Recommended (50%) ✓ Fits season (140 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Apr 28 – May 26
Safe Start (90%) ✓ Fits season (142 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: May 11 – Jun 8

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 Lucas County

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

Soil pH

Your soil pH (6.3–6.9) is within Microgreens's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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

34
successive plantings in your 175-day season

Sow every 0.7 weeks. Last sowing by Sep 22 to harvest before frost.

For a dedicated fall crop, sow by Aug 04.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Only during dry spells
Season total 2 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 1.9" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 5.2" 0" ✅ Rainfall sufficient
Jun 4.3" 5.3" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Lucas 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 ~214 GDD — county provides 2,668 GDD Excellent fit

Microgreens Planting Timeline — Lucas County, IA

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 7 Apr 7 – Apr 28
Harvest April 28 Apr 28 – May 26
Fall Sowing August 4 Aug 4 – Aug 18

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

175 days in Lucas County

Growing Tips for Microgreens in Lucas County

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

Your generous 175.0-day season in Lucas 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 Lucas County, IA?

Lucas County is in Zone 5b with an average last frost of April 21. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lucas County, IA?

Lucas County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 13.

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Your Lucas County Garden Planner — Free

A 24-page printable planner built for Lucas 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 Lucas County, IA. 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.