Black Mustard is an annual grown for its foliage and form, settling in over about 60 days. It's hardy across USDA zones 6 through 10. Its spring flowers are a moderate draw for honeybees and native bees.
Zones
6-10
pH Range
5.3-7.8
Sun
Full Sun
Days to Maturity
60
Score Black Mustard on your exact land.
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What Black Mustard is
Black Mustard grows as an annual and reaches around four feet at maturity. It blooms in spring.
How to grow Black Mustard
Black Mustard grows in USDA zones 6 through 10. Black Mustard does best in full sun — at least 6 hours of direct sun a day — and soil from pH 5.3 to 7.8, on well-drained ground. It needs a growing season of at least 120 frost-free days, which is why climate matters as much as soil.
USDA Zones
6-10
USDA PHZM 2023
Soil pH
5.3 - 7.8
USDA PLANTS Database
Sun
Full Sun
plant_species_v5.csv
Drainage
well (dry spells)
plant_species_v5.csv
Frost Tolerance
41°F
plant_species_v5.csv
Days to Maturity
60 days
Black mustard; biofumigant cover crop. Days = typical termination point before flowering.
USDA-NRCS
Mature Height
4 ft
plant_species_v5.csv
Frost-Free Days
120+
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Start the season right
Plant black mustard in full sun with at least 6 hours of direct sun, once the soil has warmed and frost risk has passed.
Match the soil
Black Mustard prefers pH 5.3 to 7.8 (USDA PLANTS Database). A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band.
Water steadily
Keep the root zone evenly moist through establishment. A 2–3 inch mulch layer holds moisture without waterlogging.
Keep it in good form
Prune black mustard to shape as it grows; the reward is its foliage and structure, not a harvest, so steady upkeep is the whole job.
Good to know
Good news for pet owners — black mustard isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Black Mustard offers moderate value to bees and other pollinators. (Source: Xerces Society, Pollinator Partnership.)
Where Black Mustard thrives
Black Mustard is hardy across USDA zones 6 through 10. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
Zones 6–10·Where Black Mustard growsOpen map →
On USDA hardiness-zone overlap, Black Mustard can grow in these states:
See if Black Mustard will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether black mustard actually takes — we score it against the real conditions at your address.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Frequently Asked Questions
Can I grow Black Mustard in my zone?
Black Mustard grows in USDA hardiness zones 6 through 10 (USDA PHZM 2023). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
When should you plant Black Mustard?
Most growers plant black mustard after the last spring frost, once the soil has warmed, leaving enough of the season for its 120-day frost-free need. Your local frost dates set the exact window — a Growable Ground report reads them for your address.
How much sun does Black Mustard need?
Black Mustard needs full sun — a spot that catches at least 6 hours of direct summer sun a day. In more shade it still grows, but usually gives a smaller, later crop. The catch is that a yard rarely gets even light everywhere — a fence, the house, or one tall tree can quietly take those hours. A Growable Ground report reads the real sun-hours across your land, canopy and buildings included, so you can pick the brightest bed before you plant.
What soil does Black Mustard need?
Black Mustard prefers soil pH 5.3 to 7.8, on well-drained ground (USDA PLANTS Database). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Black Mustard attract pollinators?
Yes — black mustard's flowers are a solid nectar source for honeybees and native bees (Xerces Society, Pollinator Partnership).
Is Black Mustard safe for pets?
Black Mustard is not known to be toxic to dogs or cats based on available data (ASPCA). Always supervise pets around new plantings.