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When to Plant Microgreens in Knox County, MO

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.

Knox County, Missouri is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.

At an elevation of 997 feet, Knox County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Microgreens to ensure they mature before fall.

Knox County, MO (Zone 5b) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (148 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Apr 18 – May 16
Recommended (50%) ✓ Fits season (148 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Apr 24 – May 22
Safe Start (90%) ✓ Fits season (144 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: May 10 – Jun 7

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 137 gal / 100 sq ft
Microgreens needs ~172 GDD — county provides 2,241 GDD Excellent fit

Microgreens Planting Timeline โ€” Knox County, MO

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 โ€“ Mar 27
Transplant Outdoors April 17 Apr 17 โ€“ May 1
Direct Sow April 3 Apr 3 โ€“ Apr 24
Fall Sowing August 8 Aug 8 โ€“ Aug 22
Harvest April 24 Apr 24 โ€“ May 22

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

7โ€“21 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

183 days

Growing Tips for Knox County

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 Knox County, MO?

Knox County is in Zone 5b with an average last frost of April 17. Plan your Microgreens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Knox County, MO?

Knox County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Knox County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Knox County, MO. Local conditions may vary. Last updated: April 2026.