spear grass (Heteropogon contortus), photographi

Can I Grow Spear Grass in Ohio?

USDA Zones 5b-7a · Plant zone range 9-13

Unlikely — Zone Mismatch

spear grass (zones 9-13) does not overlap with Ohio's zone range (5b-7a). Growing outdoors is unlikely without significant protection.

2 zones short — what would close it

Spear Grass is hardy to zone 9, and the warmest ground in Ohio is zone 7 — 2 zones short. Planted in open ground it will not survive a Ohio winter. To grow it here, grow spear grass in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.

An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →

Zone math from 9-13 (plant) against 5-7 (Ohio). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.

Spear Grass in Ohio — the short answer

Spear Grass in Ohio: hardy in zones 9–13, full sun, against a state median of ~208 frost-free days.

Plant zones
9-13
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
Ohio zones
5b-7a
USDA PHZM 2023
Frost window
Apr 5 - Apr 13 – Oct 31 - Nov 6
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
182 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free

Your yard isn't the whole zone.

Ohio spans zones 5b-7a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score spear grass against your land's actual soil, sun, and frost.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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Ohio is not one climate

A single Ohio answer averages 88 counties whose growing seasons are 57 days apart — from 182 frost-free days in Columbiana County to 239 in Cuyahoga County. Which end of that your land sits nearer changes what spear grass can finish before the first hard freeze.

182 daysColumbiana County239 daysCuyahoga County

The middle half of 88 counties runs 201214 days, with a median of 208 days — a 57-day span end to end.

Measured across 88 Ohio counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where Spear Grass Stands in Ohio

Spear Grass is rated for zones 913 — a cold floor USDA puts at 20 to 30°F. No Ohio county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Ohio winters, not about spear grass.

Below the zone 9 floor

88 counties

3 of 88 shown

Winter cold is the limit here — the same plant works in a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.

Zone Comparison

Spear Grass Needs

  • USDA Zones: 9-13
  • Frost-Free Days: 120+
  • Sun: Full Sun
  • Mature size: 8 in tall
  • Drought tolerance: High

Ohio Has

  • USDA Zones: 5b-7a
  • Last Hard Freeze (28°F): Apr 5 - Apr 13
  • First Hard Freeze (28°F): Oct 31 - Nov 6
  • Annual Rainfall: 34-42 inches
  • Common Soils: Glacial till, Clay loam, Silt loam

Plant Zone Range (zones 9-13)

9a
13b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.58.5

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Spear Grass in Ohio

The frost window

Across Ohio, the last spring hard freeze (28°F) clears between Apr 5 and Apr 13, and the first fall hard freeze lands between Oct 31 and Nov 6 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 201-day window you can count on — up to 215 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

When to start the seed

Spear Grass is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Ohio's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.

Timing tuned to sub-state frost dates — Geauga County, not the statewide average.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

The zone check says spear grass does not survive a Ohio winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on Ohio under protection.

Frost-free days

Spear Grass wants 120+ frost-free days; a typical Ohio site sees ~208 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Spear Grass tolerates a wide pH range (pH 4.5-8.5) — 4 units, acid ground through alkaline — so soil acidity is rarely what limits it in Ohio. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 5 and 6 — worth knowing before you decide whether a Ohio soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Ohio site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Your land, not the state average

SSURGO maps about 28.6% of Ohio as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Spear Grass tolerates drought well, so wet feet — not dry spells — is its real risk here — your soil map unit, not the state average, is the real answer.

Check your parcel → Source: USDA NRCS SSURGO.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Ohio soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Spear Grass in Ohio

Zone compatibility tells you about winter cold survival — but Ohio growers also need to think about:

Heavy clay soils across much of northern Ohio require amendment for drainage

Variable spring weather with late frost risk through mid-May

Japanese beetles and tomato hornworms are common garden pests

Wet springs can delay planting and promote root rot

Growing spear grass here specifically

Spear Grass roots run medium and prefer pH 4.5–8.5, but drainage comes first here: SSURGO maps about 28.6% of Ohio as poorly or somewhat-poorly drained, and wet ground rots its roots before pH ever matters.

Plant spear grass on a raised, gravel-amended berm so water drains fast and the roots stays dry. How to handle it →

What to actually do about these — and the constraints that apply to every Ohio grower, not just spear grass — is covered on the Ohio growing guide.

Timing shifts within Ohio

Ohio isn't one climate. In Geauga County, the last hard freeze (28°F) holds until about Apr 22 — roughly 13 days later than the recorded state median — so plant spear grass to your county's window, not the statewide date.

Spear Grass needs about 120 days of frost-free season to complete its cycle. Even Columbiana County — Ohio’s shortest season at 182 frost-free days — clears that by 62 days, so season length isn’t the constraint anywhere in Ohio. What varies is your own parcel.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Spear Grass's 120-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Ohio Cooperative Extension

For Ohio-specific cultivar recommendations, planting calendars, and pest pressure for spear grass, the canonical source is Ohio State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Spear Grass native to Ohio?

Spear Grass is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Ohio. It can still earn a place in a Ohio garden — the zone comparison above tells you whether it will thrive.

Looking for plants that belong here? The Ohio growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Spear Grass in Ohio

When can I plant Spear Grass in Ohio?

Ohio's last spring hard freeze (28°F) clears between Apr 5 and Apr 13, and the first fall hard freeze lands between Oct 31 and Nov 6 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.

What hardiness zone is Spear Grass grown in across Ohio?

Ohio spans USDA hardiness zones 5b-7a (USDA ARS PHZM 2023). Spear Grass carries a range of zones 9-13, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Ohio site have?

A typical Ohio site sees ~208 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Spear Grass needs 120+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Geauga, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Spear Grass native to Ohio?

Spear Grass is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Ohio. It can still earn a place in a Ohio garden — the zone comparison above tells you whether it will thrive.

How should I amend the soil for Spear Grass in Ohio?

Spear Grass tolerates pH 4.5-8.5 and well (dry spells) drainage (FAO ECOCROP). That is a 4-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Ohio site — amend for drainage and organic matter first.

Will Spear Grass actually grow on my specific land in Ohio?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores spear grass against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Ohio

State-level data is a sketch. Your Growable Ground report scores spear grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Ohio spear grass averages can't show:

Your soil pHYour frost-free days — Ohio averages 208Your sun & shade

We read public map data around Ohio — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Ohio spear grass average

Explore More

Explore Ohio county by county

Ohio carries 88 counties with their own USDA zone — a sample of the growing pages for spear grass there:

Where else spear grass grows

Spear Grass's zone band crosses state lines — these are the states closest to Ohio in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.

More to grow in Ohio

Ohio has a growing page for 893 plants — a rotating sample of the rest of the shelf.

Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →

Cite this dataset

Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643

Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643

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