Can I Grow Horehound in Mississippi?

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

Yes — Strong Match

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

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Zone Comparison

Horehound Needs

  • USDA Zones: 3-9
  • Frost-Free Days: 90+
  • Sun: Full Sun
  • Mature size: 2 ft tall
  • Picking window: ~90 days of harvest
  • Drought tolerance: High

Mississippi Has

  • USDA Zones: 7b-9b
  • Last Hard Freeze (28°F): Feb 17 - Mar 3
  • First Hard Freeze (28°F): Nov 21 - Nov 30
  • Annual Rainfall: 50-65 inches
  • Common Soils: Loess, Alluvial clay, Sandy loam

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 4.57.5

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

When to Plant Horehound in Mississippi

The frost window

Across Mississippi, the last spring hard freeze (28°F) clears between Feb 17 and Mar 3, and the first fall hard freeze lands between Nov 21 and Nov 30 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 263-day window you can count on — up to 286 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 horehound goes out, not when it starts. It is sown under cover about 8 weeks ahead, so counting back from Mississippi's late-side last freeze of Mar 3 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Winter standing

Mississippi runs as cold as USDA zone 7, and no sourced winter-hardiness floor is on record for horehound, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether horehound is a permanent planting or a replant-every-spring crop for you turns on your own zone within Mississippi; 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 horehound survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Horehound wants 90+ frost-free days; a typical Mississippi site sees ~273 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

Growing degree days

Horehound needs ~800 GDD (base 50°F) to ripen. The state median runs ~5404 GDD (from PRISM 1991-2020 climate normals), so Mississippi'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

Horehound tolerates a wide pH range (pH 4.5-7.5) — 3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Mississippi. 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 5.5 and 7 — worth knowing before you decide whether a Mississippi soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Mississippi site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Plant pH and drainage requirements from USDA PLANTS Database. Mississippi soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Horehound in Mississippi — Quick Answer

  • Verdict: Yes — Strong Match
  • Plant Zones: 3-9 (USDA PLANTS Database)
  • State Zones: 7b-9b (USDA ARS PHZM 2023)
  • Growing Season: 28°F hard freezes about Feb 17 - Mar 3 to Nov 21 - Nov 30 (NOAA Regional Climate Centers ACIS, 1991-2020)
  • Days to Maturity: 90 days

What Else to Consider for Horehound in Mississippi

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

Extreme summer heat and humidity

Heavy alluvial clay in the Delta region

Frequent severe storms and flooding

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

Timing shifts within Mississippi

Horehound needs about 90 days of frost-free season to complete its cycle. Even Tishomingo County — Mississippi’s shortest season at 232 frost-free days — clears that by 142 days, so season length isn’t the constraint anywhere in Mississippi. What varies is your own parcel.

Across Mississippi’s 82 counties the frost-free season runs from 232 days in Tishomingo County to 309 days in Harrison County — a spread of 77 days, which is why a single statewide planting date misleads. The median Mississippi county sees 273 frost-free days, leaving horehound about 183 days of slack on a typical parcel — room for a second sowing where the season runs long.

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"). Horehound's 90-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Where in Mississippi Fits Best

Even within Mississippi's zones 7b-9b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for horehound (USDA PHZM 2023):

Pollinator + Wildlife Value

Horehound draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, horehound can only work that bloom inside Mississippi's frost window — roughly 273 days, opening after the last 28°F freeze (Feb 17 - Mar 3) and closing at the first (Nov 21 - Nov 30), per NOAA Regional Climate Centers ACIS, 1991-2020.

Mississippi Cooperative Extension

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

Is Horehound native to Mississippi?

No — the USDA PLANTS Database lists Horehound as introduced rather than native in the Lower 48, so it is not part of Mississippi's native flora. It grows here as a garden plant; pairing it with a few Mississippi natives keeps local pollinators fed too.

Looking for plants that belong here? The Mississippi 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 Horehound in Mississippi

When can I plant Horehound in Mississippi?

Mississippi's last spring hard freeze (28°F) clears between Feb 17 and Mar 3, and the first fall hard freeze lands between Nov 21 and Nov 30 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Horehound, so this page does not state whether it overwinters in Mississippi 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 Horehound grown in across Mississippi?

Mississippi spans USDA hardiness zones 7b-9b (USDA ARS PHZM 2023). Horehound 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 Mississippi site have?

A typical Mississippi site sees ~273 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Horehound needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Horehound native to Mississippi?

No — the USDA PLANTS Database lists Horehound as introduced rather than native in the Lower 48, so it is not part of Mississippi's native flora. It grows here as a garden plant; pairing it with a few Mississippi natives keeps local pollinators fed too.

How should I amend the soil for Horehound in Mississippi?

Horehound tolerates pH 4.5-7.5 and well (dry spells) 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 Mississippi site — amend for drainage and organic matter first.

Will Horehound actually grow on my specific land in Mississippi?

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

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

Three things about your lot that Mississippi horehound averages can't show:

Your soil pHYour frost-free days — Mississippi averages 273Your sun & shade

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

25+ data sources read at your address, not the Mississippi horehound average

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