Can I Grow Marshmallow in Indiana?

USDA Zones 5b-7b · Plant zone range 3-9

Yes — Strong Match

marshmallow (zones 3-9) covers every zone Indiana contains (5b-7b), so hardiness is not what limits it anywhere in the state.

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Your yard isn't the whole zone.

Indiana spans zones 5b-7b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score marshmallow against your parcel's actual hardiness, soil, and sun.

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Zone Comparison

Marshmallow Needs

  • USDA Zones: 3-9
  • Sun: Full Sun
  • Mature size: 4 ft tall
  • Picking window: ~60 days of harvest
  • Drought tolerance: Low

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 3-9)

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

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.58.5

Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Marshmallow 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.

When to start the seed

Those dates are when marshmallow goes out, not when it starts. It is sown under cover about 6 weeks ahead, so counting back from Indiana's late-side last freeze of Apr 9 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Winter standing

Indiana runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for marshmallow, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether marshmallow is a permanent planting or a replant-every-spring crop for you turns on your own zone within Indiana; check its hardiness range against that before treating it as long-lived ground.

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 marshmallow survives winter here. Whether the season is long enough — and warm enough — is a different question.

Days to maturity

Marshmallow matures in ~150 days (Growable Ground Plant Database). A typical Indiana site has ~209 frost-free days, so one full crop fits, with little room for replant.

Growing degree days

Marshmallow needs ~1000 GDD (base 50°F) to ripen. The state median runs ~3153 GDD (from PRISM 1991-2020 climate normals), so Indiana's typical season clears that easily.

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

Marshmallow tolerates a wide pH range (pH 5.5-8.5) — 3 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 6 and 7.5 — worth knowing before you decide whether a Indiana soil test result is a problem or just a number. Drainage requirement: poorly (saturated >50% of year). A soil-survey lookup (NRCS SSURGO) flags whether your specific site matches.

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.

Marshmallow in Indiana — Quick Answer

  • Verdict: Yes — Strong Match
  • Plant Zones: 3-9 (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)
  • Days to Maturity: 150 days

What Else to Consider for Marshmallow 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

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

Timing shifts within Indiana

Marshmallow needs about 150 days of frost-free season from planting to harvest. Even Steuben County — Indiana’s shortest season at 191 frost-free days — clears that by 41 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"). Marshmallow's 150-day requirement: USDA PLANTS / Growable Ground plant database (days to maturity). A parcel report resolves your address's own frost dates.

Where in Indiana Fits Best

Even within Indiana's zones 5b-7b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for marshmallow (USDA PHZM 2023):

Pollinator + Wildlife Value

Marshmallow draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, marshmallow can only work that bloom inside Indiana's frost window — roughly 209 days, opening after the last 28°F freeze (Apr 4 - Apr 9) and closing at the first (Oct 30 - Nov 4), per NOAA Regional Climate Centers ACIS, 1991-2020.

Indiana Cooperative Extension

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

Is Marshmallow native to Indiana?

No — the USDA PLANTS Database lists Marshmallow 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 Marshmallow in Indiana

When can I plant Marshmallow 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). No sourced winter-hardiness floor is on record for Marshmallow, so this page does not state whether it overwinters in Indiana and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.

What hardiness zone is Marshmallow grown in across Indiana?

Indiana spans USDA hardiness zones 5b-7b (USDA ARS PHZM 2023). Marshmallow carries a range of zones 3-9, 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). Marshmallow should be matched against that window, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Marshmallow native to Indiana?

No — the USDA PLANTS Database lists Marshmallow 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 Marshmallow in Indiana?

Marshmallow tolerates pH 5.5-8.5 and poorly (saturated >50% of year) drainage (Growable Ground Plant Database). That is a 3-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 Marshmallow actually grow on my specific land in Indiana?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores marshmallow 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 Indiana

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

Three things about your lot that Indiana marshmallow averages can't show:

Your soil pHYour frost-free days — Indiana averages 209Your sun & shade

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 marshmallow average

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