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When to Plant Microgreens in Washington County, MD

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.

Washington County, Maryland is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 23, giving you a growing season of approximately 190 days.

At an elevation of 1,022 feet, Washington County receives approximately 45.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Microgreens during the growing season.

Washington County, MD (Zone 6b) Moderate season
190 days
Last Spring Frost April 16
190 growing days
First Fall Frost October 23

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (153 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: Apr 19 – May 17
Recommended (50%) ✓ Fits season (155 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Apr 23 – May 21
Safe Start (90%) ✓ Fits season (142 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: May 17 – Jun 14

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Microgreens needs ~192 GDD — county provides 2,612 GDD Excellent fit

Microgreens Planting Timeline โ€” Washington County, MD

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 2 Apr 2 โ€“ Apr 23
Fall Sowing August 14 Aug 14 โ€“ Aug 28
Harvest April 23 Apr 23 โ€“ May 21

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 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 6b

Growing Season

190 days

Growing Tips for Washington 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 Washington County, MD?

Washington County is in Zone 6b with an average last frost of April 16. Plan your Microgreens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, MD?

Washington County, Maryland is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 6b 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 Washington County, MD. Local conditions may vary. Last updated: April 2026.