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When to Plant Mustard Greens in Union County, NC

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.

Union County, North Carolina is in USDA Zone 7b. The average last spring frost is March 26 and the first fall frost is November 4, giving you a growing season of approximately 223 days.

At an elevation of 1,049 feet, Union County receives approximately 53.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88ยฐF, providing good warmth for Mustard Greens during the growing season. Clay soil retains moisture well for Mustard Greens, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mustard Greens root diseases.

Union County, NC (Zone 7b) Long season
223 days
Last Spring Frost March 26
223 growing days
First Fall Frost November 4

Union County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (126 days to spare)
Start indoors: Feb 12 Transplant: Mar 19 🍅 Harvest: Apr 23 – Jun 25
Recommended (50%) ✓ Fits season (125 days to spare)
Start indoors: Feb 19 Transplant: Mar 26 🍅 Harvest: Apr 30 – Jul 2
Safe Start (90%) ✓ Fits season (120 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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Mustard Greens needs ~640 GDD — county provides 3,568 GDD Excellent fit

Mustard Greens Planting Timeline โ€” Union County, NC

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 โ€“ Mar 5
Transplant Outdoors March 26 Mar 26 โ€“ Apr 9
Direct Sow March 12 Mar 12 โ€“ Apr 2
Fall Sowing August 26 Aug 26 โ€“ Sep 9
Harvest April 30 Apr 30 โ€“ Jul 2

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 Harvest
May Harvest
June Harvest
July Harvest
August Fall Sowing
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 7b

Growing Season

223 days

Growing Tips for Union 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 Union County, NC?

Union County is in Zone 7b with an average last frost of March 26. Plan your Mustard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, NC?

Union County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is March 26 and first fall frost is November 4.

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Plan Your Garden with Confidence

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