Japanese Forest Grass is a perennial grown for its green blooms, which open in summer and return year after year. It's hardy across USDA zones 5 through 9, shrugs off deer and grows just as well in a container as in the ground.
Japanese Forest Grass — the short answer
Japanese Forest Grass: grown in zones 5–9, shade, pH 5.5–7.
- USDA zones
- 5–9
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Soil pH
- 5.5–7
- Growable Ground Plant Database
- Sun
- Shade
- Growable Ground Plant Database
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — each tile names its own row's source, because per-field provenance varies.
Score Japanese Forest Grass on your exact land.
Zone averages can't see the slope, soil, frost, and sun that decide whether japanese forest grass actually takes — and those shift from one yard to the next. Enter your address and we'll score japanese forest grass against your land's real conditions.
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What Japanese Forest Grass is
Japanese Forest Grass grows as a perennial and reaches around a foot and a half at maturity. It blooms green in summer. It's also deer-resistant and well suited to containers.
How to grow Japanese Forest Grass
Japanese Forest Grass grows in USDA zones 5 through 9. Japanese Forest Grass does best in shade — at least 2 hours of direct sun a day — and soil from pH 5.5 to 7, 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
5-9
USDA PHZM 2023
Soil pH
5.5 - 7
Growable Ground Plant Database
Sun
Shade
Growable Ground plant catalog
Drainage
well (dry spells)
Growable Ground plant catalog
Mature Height
1.5 ft
Growable Ground plant catalog
Frost-Free Days
120+
The frost-free stretch it needs start to finish — short-season areas may need an indoor head start.
Growable Ground plant catalog
Start the season right
Plant japanese forest grass in shade with at least 2 hours of direct sun. It grows in the cool halves of the year, so sow it in spring or late summer rather than waiting for midsummer heat.
Match the soil
Japanese Forest Grass prefers pH 5.5 to 7 (Growable Ground Plant 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.
Harvest at its peak
Cut japanese forest grass blooms in the cool of the morning, just as they open, for the longest display.
Where Japanese Forest Grass thrives
Japanese Forest Grass is hardy across USDA zones 5 through 9. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
A USDA zone is a 10°F band of average annual extreme winter minimum, so zones 5–9 spans average winter lows from -20°F to 30°F (USDA PHZM 2023). Across the 50 states and DC, that band covers 25 outright and splits 25 more down the middle — and which side of that line your land sits on changes the answer.
Zones 5–9·Where Japanese Forest Grass growsOpen map →
This map is derived from the USDA ARS / PRISM Plant Hardiness Zone Map (2023) and is not the official USDA Plant Hardiness Zone Map.
Where Japanese Forest Grass stands, state by state
Japanese Forest Grass is rated for zones 5–9 — a cold floor USDA puts at -20 to -10°F. Across the 50 states and DC, 25 sit fully inside that band, the line runs through 25 more, and 1 sits outside it — and inside every split state, the same line runs on at county grain.
Fully inside zones 5–9
25 states
3 of 25 shown
The line runs through
25 states
3 of 25 shown
Japanese Forest Grass’s band covers part of each of these states — which side of the line your county sits on changes the answer, and each state page draws it.
Outside zones 5–9
1 state
- North Dakota · zones 3b-4b
Winter cold is the limit here — the same plant often works in a container that comes under cover. Each link is that state’s own growing hub.
State zone extents: USDA Plant Hardiness Zone Map (PHZM) 2023. A zone is a 10°F band of average annual extreme minimum temperature, so a state that splits the band contains the boundary — its own page draws the county line, and a parcel report resolves which side your land sits on.
What grows around Japanese Forest Grass
Growing guides for japanese forest grass
In rotation planning, japanese forest grass counts as a Grass — beds recover best when grass crops don’t follow each other in the same spot year over year. (Growable Ground derivation — crop-rotation group from botanical family)
Related plants in perennial flower
Good to know
Good news for pet owners — japanese forest grass isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Japanese Forest Grass isn't classified as a notable pollinator plant in our data — pair it with high-value bloomers nearby to feed bees.
Your land is one point inside Japanese Forest Grass's range
This page resolves to the species. Your state page draws the county line, and a report reads the parcel — the soil pH, drainage, sun, and frost dates on your exact ground, which no species average can see.
See if Japanese Forest Grass will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether japanese forest 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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How we know this about Japanese Forest Grass
The figures above are cited per row, not per site: the pH band names this plant’s own source column, the three temperature figures each carry their own, and days-to-maturity cites the publication that actually lists it. All of it comes from the Growable Ground Plant Database — a compilation over FAO ECOCROP, USDA PLANTS, and university Extension sources, published openly with per-field provenance.
Grounded inUSDA PLANTS Database•USDA PHZM•ASPCA
Frequently asked questions
Can I grow Japanese Forest Grass in my zone?
Japanese Forest Grass grows in USDA hardiness zones 5 through 9 (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 Japanese Forest Grass?
Japanese Forest Grass is a cool-season crop, so it goes in during the cool halves of the year — early spring, and again in late summer for a fall planting — rather than at the height of summer heat. Your local frost dates set the exact window — a Growable Ground report reads them for your address.
How much sun does Japanese Forest Grass need?
Japanese Forest Grass is shade-tolerant — it gets by on as little as 2 hours of direct sun, so it earns a place most vegetables can't use. A north-facing strip or the ground under a leafy canopy is right where it belongs. A Growable Ground report shows which corners of your land stay shaded through the day, turning those dim spots into planting spots.
What soil does Japanese Forest Grass need?
Japanese Forest Grass prefers soil pH 5.5 to 7, on well-drained ground (Growable Ground Plant Database). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Japanese Forest Grass attract pollinators?
Japanese Forest 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 Japanese Forest Grass safe for pets?
Japanese Forest Grass is not known to be toxic to dogs or cats based on available data. Always supervise pets around new plantings. (Source: ASPCA.)
Keep exploring Japanese Forest Grass
Japanese Forest Grass state by state
Every state japanese forest grass's zone reaches — 1 link straight to that state's japanese forest grass growing page; the rest open the state's full growing guide.