Unlikely — Zone Mismatch
molasses grass (zones 9-13) does not overlap with Indiana's zone range (5b-7b). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Molasses Grass is hardy to zone 9, and the warmest ground in Indiana is zone 7 — 2 zones short. Planted in open ground it will not survive a Indiana winter. To grow it here, grow molasses grass under glass — a greenhouse is the only lift this wide the engine models.
A greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 9-13 (plant) against 5-7 (Indiana). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
Indiana spans zones 5b-7b, 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 molasses 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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Zone Comparison
Molasses Grass Needs
- USDA Zones: 9-13
- Frost-Free Days: 120+
- Sun: Full Sun
Indiana Has
- USDA Zones: 5b-7b
- Last Hard Freeze (28°F): Apr 4 - Apr 9
- First Hard Freeze (28°F): Oct 30 - Nov 4
- Annual Rainfall: 36-46 inches
- Common Soils: Silt loam, Clay loam, Glacial till
Plant Zone Range (zones 9-13)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Molasses Grass in Indiana
The frost window
Across Indiana, the last spring hard freeze (28°F) clears between Apr 4 and Apr 9, and the first fall hard freeze lands between Oct 30 and Nov 4 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 204-day window you can count on — up to 214 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.
Frost tenderness
Molasses Grass is frost-tender — its listed minimum temperature is 46.4°F (USDA PLANTS Database) — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does.
When to start the seed
Molasses Grass is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Indiana'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 — Steuben County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. 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 molasses grass does not survive a Indiana 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 Indiana under protection.
Frost-free days
Molasses Grass wants 120+ frost-free days; a typical Indiana site sees ~209 (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
Molasses Grass tolerates a wide pH range (pH 4.3-8.4) — 4.1 units, acid ground through alkaline — so soil acidity is rarely what limits it in Indiana. 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 7.5 — worth knowing before you decide whether a Indiana soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Indiana 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 37.8% of Indiana as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Molasses Grass sits mid-range for drought tolerance, so either extreme can cost you — your soil map unit, not the state average, is the real answer.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Indiana soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Molasses Grass in Indiana — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 9-13 (USDA PLANTS Database)
- State Zones: 5b-7b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Apr 4 - Apr 9 to Oct 30 - Nov 4 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Molasses Grass in Indiana
Zone compatibility tells you about winter cold survival — but Indiana growers also need to think about:
Heavy clay soils limit drainage in many areas
Late spring frosts through early May
Hot humid summers promote blight and mildew
Growing molasses grass here specifically
Molasses Grass likes pH 4.3–8.4 and takes cold to about 46°F, yet neither saves it from wet feet — SSURGO maps about 37.8% of Indiana poorly-drained, where its roots sit and rot.
Set molasses grass high on bermed, grit-amended ground so winter and storm water drain away from the roots. How to handle it →
What to actually do about these — and the constraints that apply to every Indiana grower, not just molasses grass — is covered on the Indiana growing guide.
Timing shifts within Indiana
Indiana isn't one climate. In Steuben County, the last hard freeze (28°F) holds until about Apr 18 — roughly 11 days later than the recorded state median — so plant molasses grass to your county's window, not the statewide date.
Molasses Grass needs about 120 days of frost-free season to complete its cycle. Even Steuben County — Indiana’s shortest season at 191 frost-free days — clears that by 71 days, so season length isn’t the constraint anywhere in Indiana. 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"). Molasses 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.
Indiana Cooperative Extension
For Indiana-specific cultivar recommendations, planting calendars, and pest pressure for molasses grass, the canonical source is Purdue Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Molasses Grass native to Indiana?
No — the USDA PLANTS Database lists Molasses Grass as introduced rather than native in the Lower 48, so it is not part of Indiana's native flora. It grows here as a garden plant; pairing it with a few Indiana natives keeps local pollinators fed too.
Looking for plants that belong here? The Indiana 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 Molasses Grass in Indiana
When can I plant Molasses Grass in Indiana?
Indiana's last spring hard freeze (28°F) clears between Apr 4 and Apr 9, and the first fall hard freeze lands between Oct 30 and Nov 4 (NOAA Regional Climate Centers ACIS, 1991-2020). Molasses Grass is frost-tender — its listed minimum temperature is 46.4°F (USDA PLANTS Database) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.
What hardiness zone is Molasses Grass grown in across Indiana?
Indiana spans USDA hardiness zones 5b-7b (USDA ARS PHZM 2023). Molasses 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 Indiana site have?
A typical Indiana site sees ~209 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Molasses 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 Steuben, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Molasses Grass native to Indiana?
No — the USDA PLANTS Database lists Molasses Grass as introduced rather than native in the Lower 48, so it is not part of Indiana's native flora. It grows here as a garden plant; pairing it with a few Indiana natives keeps local pollinators fed too.
How should I amend the soil for Molasses Grass in Indiana?
Molasses Grass tolerates pH 4.3-8.4 and well (dry spells) drainage (FAO ECOCROP). That is a 4.1-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Indiana site — amend for drainage and organic matter first.
Will Molasses Grass actually grow on my specific land in Indiana?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores molasses grass against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Indiana
State-level data is a sketch. Your Growable Ground report scores molasses grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Indiana molasses grass averages can't show:
We read public map data around Indiana — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Indiana molasses grass average
Explore More
Growing guides for molasses grass
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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