Generally — Most Areas
asystasia (zones 10-13) suits most of Florida (8b-12a) — zones 10-12 are in range, and the rest of the state is the exception.
Asystasia in Florida — the short answer
Asystasia in Florida: hardy in zones 10–13, part sun, against a state median of ~320 frost-free days.
- Plant zones
- 10-13
- 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
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.
Florida spans zones 8b-12a, 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 asystasia against your land's actual soil, sun, and frost.
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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 asystasia 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
Asystasia is rated for zones 10–13 — a cold floor USDA puts at 30 to 40°F. Against Florida’s 67 counties that band holds in 20 of them, and the line runs at Brevard County (zone 10a), the coldest county still inside it.
Inside zones 10–13
20 counties
- Charlotte County · zone 10a
- Collier County · zone 10a
- Glades County · zone 10a
3 of 20 shown
Below the zone 10 floor
47 counties
- Holmes County · zone 8b
- Alachua County · zone 9a
- Baker County · zone 9a
3 of 47 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Even within Florida's zones 8b-12a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for asystasia (USDA PHZM 2023):
Zone Comparison
Asystasia Needs
- USDA Zones: 10-13
- Frost-Free Days: 42+
- Sun: Part Sun
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 10-13)
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 Asystasia 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.
When to start the seed
Asystasia is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Florida'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.
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 asystasia 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
Asystasia wants 42+ frost-free days; a typical Florida site sees ~320 (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
Asystasia prefers acidic soil (pH 3.5-5). Florida's sandy can run on the acidic side, which often aligns well — confirm with a soil test before planting. It will grow across that whole span, but it does best between pH 4 and 4.5 — worth knowing before you decide whether a Florida soil test result is a problem or just a number. Drainage matters: this plant wants poorly (saturated >50% of year), well (dry spells). If your Florida site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
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 Asystasia 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
What to actually do about these — and the constraints that apply to every Florida grower, not just asystasia — is covered on the Florida growing guide.
Timing shifts within Florida
Asystasia needs about 42 days of frost-free season to complete its cycle. Even Holmes County — Florida’s shortest season at 281 frost-free days — clears that by 239 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 asystasia about 278 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"). Asystasia's 42-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Asystasia draws honeybees, native bees, and butterflies (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, asystasia can only work that bloom inside Florida's frost window — roughly 320 days, opening after the last 28°F freeze (Jan 25 - Feb 10) and closing at the first (Dec 7 - Dec 18), per NOAA Regional Climate Centers ACIS, 1991-2020.
Florida Cooperative Extension
For Florida-specific cultivar recommendations, planting calendars, and pest pressure for asystasia, the canonical source is UF/IFAS Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Asystasia native to Florida?
No — the USDA PLANTS Database lists Asystasia 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 Asystasia in Florida
When can I plant Asystasia 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). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
What hardiness zone is Asystasia grown in across Florida?
Florida spans USDA hardiness zones 8b-12a (USDA ARS PHZM 2023). Asystasia carries a range of zones 10-13, 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). Asystasia needs 42+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Asystasia native to Florida?
No — the USDA PLANTS Database lists Asystasia 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 Asystasia in Florida?
Asystasia prefers pH 3.5-5 and poorly (saturated >50% of year), well (dry spells) drainage (FAO ECOCROP). Most Florida soils run mildly acidic to neutral; many sites land near this band naturally, and a soil test plus targeted sulfur or organic amendment closes any gap.
Will Asystasia actually grow on my specific land in Florida?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores asystasia 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 asystasia against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Florida asystasia 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 asystasia average
Explore More
Growing guides for asystasia
Explore Florida county by county
Florida carries 67 counties with their own USDA zone — a sample of the growing pages for asystasia there:
Where else asystasia grows
Asystasia's zone band crosses state lines — these are the states closest to Florida in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Florida
Florida has a growing page for 1,035 plants — a rotating sample of the rest of the shelf.
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