Generally — Most Areas
amaranth (zones 2-11) suits most of Florida (8b-12a) — zones 8-11 are in range, and the rest of the state is the exception.
Amaranth in Florida — the short answer
Amaranth in Florida: hardy in zones 2–11, full sun, against a state median of ~320 frost-free days.
- Plant zones
- 2-11
- 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
- Florida zones
- 8b-12a
- USDA PHZM 2023
- Frost window
- Jan 25 - Feb 10 – Dec 7 - Dec 18
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 281 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 90 days
- Growable Ground Plant Database
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.
Your yard isn't the whole zone.
Amaranth is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Florida site runs ~320 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score amaranth against your land's actual frost dates, sun, and soil.
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Florida is not one climate
A single Florida answer averages 67 counties whose growing seasons are 84 days apart — from 281 frost-free days in Holmes County to 365 in Sarasota County. Which end of that your land sits nearer changes what amaranth can finish before the first hard freeze.
The middle half of 67 counties runs 300–333 days, with a median of 320 days — a 84-day span end to end.
Measured across 67 Florida 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 in Florida Fits Best
Even within Florida's zones 8b-12a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for amaranth (USDA PHZM 2023):
Zone Comparison
Amaranth Needs
- USDA Zones: 2-11
- Frost-Free Days: 30+
- Sun: Full Sun
- Mature size: 4 ft tall
- Picking window: ~30 days of harvest
- Drought tolerance: Low
Florida Has
- USDA Zones: 8b-12a
- Last Hard Freeze (28°F): Jan 25 - Feb 10
- First Hard Freeze (28°F): Dec 7 - Dec 18
- Annual Rainfall: 50-65 inches
- Common Soils: Sandy, Muck (Everglades), Shell-rock (Keys)
Plant Zone Range (zones 2-11)
Preferred Soil pH
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 Amaranth in Florida
The frost window
Across Florida, the last spring hard freeze (28°F) clears between Jan 25 and Feb 10, and the first fall hard freeze lands between Dec 7 and Dec 18 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 300-day window you can count on — up to 327 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
Amaranth is frost-tender — FAO ECOCROP puts its killing temperature at 32°F — 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. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.
When to start the seed
Those dates are when amaranth goes out, not when it starts. It is sown under cover about 4 weeks ahead, so counting back from Florida's late-side last freeze of Feb 10 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Days to maturity vs. the window
At 90 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 210 days to spare even in Florida's tightest freeze scenario — room for a later start or a second sowing.
Timing tuned to sub-state frost dates — Holmes 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 amaranth survives winter in part of Florida, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Amaranth wants 30+ frost-free days; a typical Florida site sees ~320 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Amaranth needs ~1200 GDD (base 50°F) to ripen. The state median runs ~7743 GDD (from PRISM 1991-2020 climate normals), so Florida'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
Amaranth tolerates a wide pH range (pH 4.3-8.5) — 4.2 units, acid ground through alkaline — so soil acidity is rarely what limits it in Florida. 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 7.5 — worth knowing before you decide whether a Florida soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Florida 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 44.6% of Florida as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Amaranth has low drought tolerance, so it is the fast-draining end that will cost you — 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. Florida soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Amaranth in Florida
Zone compatibility tells you about winter cold survival — but Florida growers also need to think about:
Sandy soils drain too fast and hold few nutrients — frequent fertilization needed
Humidity drives fungal diseases (powdery mildew, black spot, rust)
Hurricane season (June-November) can destroy plantings
Nematodes are a serious pest in sandy FL soils
Growing amaranth here specifically
Amaranth rates to USDA zones 2–11 and takes frost damage on growing tissue around 32°F (FAO ECOCROP), but cold isn't the risk in Florida — wet is: with roughly 44.6% of its soils poorly-drained (SSURGO), soggy ground rots the roots.
Give amaranth a raised bed or mounded row with coarse amendment so its roots never sit wet. How to handle it →
What to actually do about these — and the constraints that apply to every Florida grower, not just amaranth — is covered on the Florida growing guide.
Timing shifts within Florida
Florida isn't one climate. In Holmes County, the last hard freeze (28°F) holds until about Feb 20 — roughly 16 days later than the recorded state median — so plant amaranth to your county's window, not the statewide date.
Amaranth needs about 30 days of frost-free season to complete its cycle. Even Holmes County — Florida’s shortest season at 281 frost-free days — clears that by 251 days, so season length isn’t the constraint anywhere in Florida. What varies is your own parcel.
Across Florida’s 67 counties the frost-free season runs from 281 days in Holmes County to 365 days in Sarasota County — a spread of 84 days, which is why a single statewide planting date misleads. The median Florida county sees 320 frost-free days, leaving amaranth about 290 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"). Amaranth's 30-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Recommended Amaranth Varieties for Florida
Florida publishes no state variety trial for amaranth, so we won't invent a "best for Florida" list. Choose types rated to your USDA hardiness zone (8b-12a), and confirm winter survival and drainage against your own parcel.
Florida Cooperative Extension
For Florida-specific cultivar recommendations, planting calendars, and pest pressure for amaranth, the canonical source is UF/IFAS Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Amaranth native to Florida?
No — the USDA PLANTS Database lists Amaranth as introduced rather than native in the Lower 48, so it is not part of Florida's native flora. It grows here as a garden plant; pairing it with a few Florida natives keeps local pollinators fed too.
Looking for plants that belong here? The Florida 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 Amaranth in Florida
When can I plant Amaranth in Florida?
Florida's last spring hard freeze (28°F) clears between Jan 25 and Feb 10, and the first fall hard freeze lands between Dec 7 and Dec 18 (NOAA Regional Climate Centers ACIS, 1991-2020). Amaranth is frost-tender — its killing temperature is 32°F (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.
Can Amaranth mature before first frost in Florida?
Yes — Amaranth matures in 90 days (Growable Ground Plant Database), and Florida's dependable hard-freeze-free window runs 300 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 210 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.
What hardiness zone is Amaranth grown in across Florida?
Florida spans USDA hardiness zones 8b-12a (USDA ARS PHZM 2023). Amaranth 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 Florida site have?
A typical Florida site sees ~320 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Amaranth needs 30+ 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 Holmes, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Amaranth native to Florida?
No — the USDA PLANTS Database lists Amaranth as introduced rather than native in the Lower 48, so it is not part of Florida's native flora. It grows here as a garden plant; pairing it with a few Florida natives keeps local pollinators fed too.
How should I amend the soil for Amaranth in Florida?
Amaranth tolerates pH 4.3-8.5 and well (dry spells) drainage (FAO ECOCROP). That is a 4.2-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Florida site — amend for drainage and organic matter first.
Will Amaranth actually grow on my specific land in Florida?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores amaranth 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 Florida
State-level data is a sketch. Your Growable Ground report scores amaranth against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Florida amaranth averages can't show:
We read public map data around Florida — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Florida amaranth average
Explore More
Growing guides for amaranth
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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