When to Plant Mustard Greens in St. Mary's 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.
St. Mary's County, Maryland is in USDA Zone 7a. The average last spring frost is April 5 and the first fall frost is November 4, giving you a growing season of approximately 213 days.
At an elevation of 156 feet, St. Mary's County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Mustard Greens during the growing season.
St. Mary's County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.9
Drainage
Well Drained
Plant Planting Risk Windows
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
Mustard Greens Planting Timeline — St. Mary's County, MD
Mustard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 1 | Mar 1 – Mar 15 |
| Transplant Outdoors | April 5 | Apr 5 – Apr 19 |
| Direct Sow | March 22 | Mar 22 – Apr 12 |
| Fall Sowing | August 26 | Aug 26 – Sep 9 |
| Harvest | May 10 | May 10 – Jul 12 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
30–50 days
Soil pH
6 – 7
USDA Zone
Zone 7a
Growing Season
213 days
Growing Tips for St. Mary's 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
Level Up Your Garden
Mustard Greens in Other Locations
Frequently Asked Questions
When should I plant Mustard Greens in St. Mary's County, MD?
St. Mary's County is in Zone 7a with an average last frost of April 5. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Mary's County, MD?
St. Mary's County, Maryland is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is November 4.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help St. Mary's County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.
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