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When to Plant Mustard Greens in Charles County, MD

Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

Charles County, Maryland is in USDA Zone 7a. The average last spring frost is March 29 and the first fall frost is November 14, giving you a growing season of approximately 230 days.

At an elevation of 382 feet, Charles County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Mustard Greens during the growing season.

Charles County, MD (Zone 7a) Long season
230 days
Last Spring Frost March 29
230 growing days
First Fall Frost November 14

Charles County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (127 days to spare)
Start indoors: Feb 17 Transplant: Mar 24 🍅 Harvest: Apr 28 – Jun 30
Recommended (50%) ✓ Fits season (132 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 3 – Jul 5
Safe Start (90%) ✓ Fits season (139 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: May 21 – Jul 23

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
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 615 gal / 100 sq ft
Mustard Greens needs ~730 GDD — county provides 4,197 GDD Excellent fit

Mustard Greens Planting Timeline โ€” Charles County, MD

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 โ€“ Mar 8
Transplant Outdoors March 29 Mar 29 โ€“ Apr 12
Direct Sow March 15 Mar 15 โ€“ Apr 5
Fall Sowing September 5 Sep 5 โ€“ Sep 19
Harvest May 3 May 3 โ€“ Jul 5

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“50 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

230 days

Growing Tips for Charles County

Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Mustard Greens in Charles County, MD?

Charles County is in Zone 7a with an average last frost of March 29. Plan your Mustard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Charles County, MD?

Charles County, Maryland is in USDA Hardiness Zone 7a. The average last spring frost is March 29 and first fall frost is November 14.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Charles County gardeners in Zone 7a 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 Charles County, MD. Local conditions may vary. Last updated: April 2026.