Can I Grow Tithonia in Arkansas?

USDA Zones 6b-8b · Plant zone range 2-11

Yes — Strong Match

tithonia (zones 2-11) covers every zone Arkansas contains (6b-8b), so hardiness is not what limits it anywhere in the state.

Score your parcel · free

Your yard isn't the whole zone.

Arkansas spans zones 6b-8b, 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 tithonia against your parcel's actual hardiness, soil, and sun.

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

No card required · your full report in seconds

Zone Comparison

Tithonia Needs

  • USDA Zones: 2-11
  • Sun: Full Sun
  • Mature size: 5 ft tall
  • Picking window: ~90 days of harvest
  • Drought tolerance: High

Arkansas Has

  • USDA Zones: 6b-8b
  • Last Hard Freeze (28°F): Mar 2 - Mar 20
  • First Hard Freeze (28°F): Nov 15 - Nov 23
  • Annual Rainfall: 44-56 inches
  • Common Soils: Silt loam, Sandy loam, Red clay

Plant Zone Range (zones 2-11)

2a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.57.5

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

When to Plant Tithonia in Arkansas

The frost window

Across Arkansas, the last spring hard freeze (28°F) clears between Mar 2 and Mar 20, and the first fall hard freeze lands between Nov 15 and Nov 23 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 240-day window you can count on — up to 266 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 tithonia goes out, not when it starts. It is sown under cover about 6 weeks ahead, so counting back from Arkansas's late-side last freeze of Mar 20 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Winter standing

Arkansas runs as cold as USDA zone 6, and no sourced winter-hardiness floor is on record for tithonia, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether tithonia is a permanent planting or a replant-every-spring crop for you turns on your own zone within Arkansas; 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 tithonia survives winter here. Whether the season is long enough — and warm enough — is a different question.

Days to maturity

Tithonia matures in ~80 days (Growable Ground Plant Database). A typical Arkansas site has ~254 frost-free days, so plenty of room for a second succession.

Growing degree days

Tithonia needs ~1800 GDD (base 50°F) to ripen. The state median runs ~4819 GDD (from PRISM 1991-2020 climate normals), so Arkansas'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

Tithonia likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across Arkansas's silt loam and sandy loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 7 — worth knowing before you decide whether a Arkansas soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Arkansas 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. Arkansas soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Tithonia in Arkansas — Quick Answer

  • Verdict: Yes — Strong Match
  • Plant Zones: 2-11 (USDA PLANTS Database)
  • State Zones: 6b-8b (USDA ARS PHZM 2023)
  • Growing Season: 28°F hard freezes about Mar 2 - Mar 20 to Nov 15 - Nov 23 (NOAA Regional Climate Centers ACIS, 1991-2020)
  • Days to Maturity: 80 days

What Else to Consider for Tithonia in Arkansas

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

Hot, humid summers drive fungal and bacterial diseases

Heavy clay soils in parts of the Ozarks

Severe spring storms and hail risk

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

Timing shifts within Arkansas

Tithonia needs about 80 days of frost-free season from planting to harvest. Even Benton County — Arkansas’s shortest season at 226 frost-free days — clears that by 146 days, so season length isn’t the constraint anywhere in Arkansas. 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"). Tithonia's 80-day requirement: USDA PLANTS / Growable Ground plant database (days to maturity). A parcel report resolves your address's own frost dates.

Where in Arkansas Fits Best

Even within Arkansas's zones 6b-8b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for tithonia (USDA PHZM 2023):

Pollinator + Wildlife Value

Tithonia draws honeybees, native bees, butterflies, and hummingbirds (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, tithonia can only work that bloom inside Arkansas's frost window — roughly 254 days, opening after the last 28°F freeze (Mar 2 - Mar 20) and closing at the first (Nov 15 - Nov 23), per NOAA Regional Climate Centers ACIS, 1991-2020.

Arkansas Cooperative Extension

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

Is Tithonia native to Arkansas?

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

Looking for plants that belong here? The Arkansas 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 Tithonia in Arkansas

When can I plant Tithonia in Arkansas?

Arkansas's last spring hard freeze (28°F) clears between Mar 2 and Mar 20, and the first fall hard freeze lands between Nov 15 and Nov 23 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Tithonia, so this page does not state whether it overwinters in Arkansas 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 Tithonia grown in across Arkansas?

Arkansas spans USDA hardiness zones 6b-8b (USDA ARS PHZM 2023). Tithonia carries a range of zones 2-11, so the overlap zones are where outdoor growing is most reliable.

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

A typical Arkansas site sees ~254 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Tithonia 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 Tithonia native to Arkansas?

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

How should I amend the soil for Tithonia in Arkansas?

Tithonia prefers pH 5.5-7.5 and well (dry spells) drainage (Growable Ground Plant Database). That sits in the common-ground band across Arkansas soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Tithonia actually grow on my specific land in Arkansas?

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

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

Three things about your lot that Arkansas tithonia averages can't show:

Your soil pHYour frost-free days — Arkansas averages 254Your sun & shade

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

25+ data sources read at your address, not the Arkansas tithonia average

Last updated: