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When to plant Microgreens in Hamilton County, IL

In Zone 6b (Hamilton County), direct-sow Microgreens between March 26 and April 16 for spring, after the April 9 last-frost mark. A second sowing from August 14 to August 28 extends the harvest into fall.

When to Plant Microgreens in Hamilton County, IL

Hamilton County, Illinois Zone 6b August

Your August game plan for Hamilton County, Illinois

Your Hamilton County, Illinois garden is entering a new phase. Here's what's on the schedule for August and why each task matters now.

Avg. last frost April 9
Avg. first frost October 23
Soil temp (4") 81°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Get microgreens in for a late-season harvest

    Your first frost is about 10 weeks away — plenty of time for these to mature.

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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.

Hamilton County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 23, giving you a growing season of approximately 197 days.

At an elevation of 524 feet, Hamilton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Microgreens during the growing season.

Hamilton County, IL (Zone 6b) Moderate season
197 days
Last Spring Frost April 9
197 growing days
First Fall Frost October 23

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Microgreens Planting Risk Windows

Early Start (70% safe) ✓ Fits season (162 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: Apr 10 – May 8
Recommended (50%) ✓ Fits season (162 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: Apr 16 – May 14
Safe Start (90%) ✓ Fits season (172 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🍅 Harvest: Apr 27 – May 25

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 Hamilton County

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

Soil pH

Your soil pH (5.8–6.7) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — 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

39
successive plantings in your 197-day season

Sow every 0.7 weeks. Last sowing by Oct 02 to harvest before frost.

For a dedicated fall crop, sow by Aug 14.

Microgreens Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 355 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 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hamilton 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 ~245 GDD — county provides 3,447 GDD Excellent fit

Microgreens Planting Timeline — Hamilton County, IL

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow March 26 Mar 26 – Apr 16
Harvest April 16 Apr 16 – May 14
Fall Sowing August 14 Aug 14 – Aug 28

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
October
November
December

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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

197 days in Hamilton County

Growing Tips for Microgreens in Hamilton County

Direct sow Microgreens outdoors after April 09 in Hamilton County when soil has warmed and frost danger has passed.

Your generous 197.0-day season in Hamilton 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 Hamilton County, IL?

Hamilton County is in Zone 6b with an average last frost of April 9. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, IL?

Hamilton County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 23.

When should I plant Microgreens in Hamilton County, IL?

In Hamilton County, IL, plant Microgreens after the last frost (around April 9) and before the first frost (around October 23). Best results when soil holds above 50°F.

What growing zone is Hamilton County, IL for Microgreens?

Hamilton County sits in USDA Zone 6b. Microgreens grows reliably in zones 1a through 13b, so it's a good fit here.

Can Microgreens grow in Hamilton County's climate?

Yes — Microgreens grows well in Hamilton County's temperate climate. Hamilton County averages a 197-day frost-free season, with last frost around April 9 and first frost around October 23.

🌱

Your Hamilton County Garden Planner — Free

A 22-page printable planner built for Hamilton County (Zone 6b). 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 Hamilton County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.