Spear Grass is a cover crop — grown to build and protect the soil rather than for a harvest of its own. It's hardy across USDA zones 9 through 13 and shrugs off dry spells.
Zones
9-13
pH Range
4.5-8.5
Sun
Full Sun
Days to Maturity
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Score Spear Grass on your exact land.
Zone averages can't see the slope, soil, frost, and sun that decide whether spear grass actually takes — and those shift from one yard to the next. Enter your address and we'll score spear grass against your land's real conditions.
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What Spear Grass is
Spear Grass reaches around 8 inches at maturity. It blooms yellow in early summer.
How to grow Spear Grass
Spear Grass grows in USDA zones 9 through 13. Spear Grass does best in full sun — at least 6 hours of direct sun a day — and soil from pH 4.5 to 8.5, 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
9-13
USDA PHZM 2023
Soil pH
4.5 - 8.5
USDA PLANTS Database
Sun
Full Sun
plant_species_v5.csv
Drainage
well (dry spells)
plant_species_v5.csv
Frost Tolerance
68°F
plant_species_v5.csv
Mature Height
0.7 ft
plant_species_v5.csv
Frost-Free Days
120+
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Start the season right
Plant spear grass in full sun with at least 6 hours of direct sun, once the soil has warmed and frost risk has passed.
Match the soil
Spear Grass prefers pH 4.5 to 8.5 (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.
Turn it in before it seeds
Cut spear grass down or turn it into the soil before it sets seed, while the growth is still green — that's when it returns the most to the ground.
Good to know
Good news for pet owners — spear grass isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Spear Grass isn't classified as a notable pollinator plant in our data — pair it with high-value bloomers nearby to feed bees.
Where Spear Grass thrives
Spear Grass is hardy across USDA zones 9 through 13. 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 9–13·Where Spear Grass growsOpen map →
Continental US shown — Alaska and US Pacific territories sit outside the federal map's polygon dataset.
On USDA hardiness-zone overlap, Spear Grass can grow in these states:
See if Spear Grass will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether spear grass 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 Spear Grass in my zone?
Spear Grass grows in USDA hardiness zones 9 through 13 (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 Spear Grass?
Most growers plant spear grass 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 Spear Grass need?
Spear Grass 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 Spear Grass need?
Spear Grass prefers soil pH 4.5 to 8.5, on well-drained ground (USDA PLANTS Database). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Spear Grass attract pollinators?
Spear Grass isn't classified as a notable pollinator plant in our data. Pairing it with high-value bloomers nearby keeps bees and butterflies fed.
Is Spear Grass safe for pets?
Spear Grass is not known to be toxic to dogs or cats based on available data (ASPCA). Always supervise pets around new plantings.