Unlikely — Zone Mismatch
sea hibiscus (zones 10-12) does not overlap with District of Columbia's zone range (7b-8a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Sea Hibiscus is hardy to zone 10, and the warmest ground in District Of Columbia is zone 8 — 2 zones short. Planted in open ground it will not survive a District Of Columbia winter. To grow it here, grow sea hibiscus in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.
An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 10-12 (plant) against 7-8 (District of Columbia). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.
Sea Hibiscus in District of Columbia — the short answer
Sea Hibiscus in District of Columbia: hardy in zones 10–12, full sun, against a state median of ~254 frost-free days.
- Plant zones
- 10-12
- 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
- District of Columbia zones
- 7b-8a
- USDA PHZM 2023
- Frost window
- Mar 15 – Nov 24
- NOAA RCC ACIS 1991-2020, 28°F
- Typical season
- ~254 days
- NOAA Regional Climate Centers ACIS, 1991-2020
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.
District of Columbia spans zones 7b-8a, 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 sea hibiscus against your parcel's actual hardiness, soil, and sun.
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Where Sea Hibiscus Stands in District of Columbia
Sea Hibiscus is rated for zones 10–12 — a cold floor USDA puts at 30 to 40°F. No District of Columbia county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about District of Columbia winters, not about sea hibiscus.
Below the zone 10 floor
1 county
- District of Columbia County · zone 8a
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.
Zone Comparison
Sea Hibiscus Needs
- USDA Zones: 10-12
- Frost-Free Days: 270+
- Sun: Full Sun
District of Columbia Has
- USDA Zones: 7b-8a
- Last Hard Freeze (28°F): Mar 15
- First Hard Freeze (28°F): Nov 24
- Annual Rainfall: 39-43 inches
- Common Soils: Urban fill, Silt loam, Clay loam
Plant Zone Range (zones 10-12)
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 Sea Hibiscus in District of Columbia
The frost window
Across District of Columbia, the last spring hard freeze (28°F) clears between Mar 15 and Mar 15, and the first fall hard freeze lands between Nov 24 and Nov 24 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 254-day window you can count on — up to 254 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.
Winter standing
District of Columbia runs as cold as USDA zone 7, and no sourced winter-hardiness floor is on record for sea hibiscus, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether sea hibiscus is a permanent planting or a replant-every-spring crop for you turns on your own zone within District of Columbia; check its hardiness range against that before treating it as long-lived ground.
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 sea hibiscus does not survive a District of Columbia winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on District of Columbia under protection.
Frost-free days
Sea Hibiscus wants 270+ frost-free days; a typical District of Columbia site sees ~254 (NOAA Regional Climate Centers ACIS, 1991-2020) — 16 days short of what it needs. A typical District of Columbia season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.
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
Sea Hibiscus likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across District of Columbia's urban fill and silt 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 District of Columbia soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your District of Columbia site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
District Of Columbia's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Sea Hibiscus needs about 19 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how sea hibiscus performs.
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. District of Columbia soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Sea Hibiscus in District of Columbia
Zone compatibility tells you about winter cold survival — but District of Columbia growers also need to think about:
Dense urban siting means small lots, compacted fill soils, and limited sun
Summer heat and humidity promote fungal diseases
The urban heat-island effect pushes summer temperatures above surrounding suburbs
Growing sea hibiscus here specifically
District Of Columbia's soils run mostly silt loam (Ultisols), and whether that suits sea hibiscus's pH 5.5–7.5 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward sea hibiscus's 5.5–7.5 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every District of Columbia grower, not just sea hibiscus — is covered on the District of Columbia growing guide.
Pollinator + Wildlife Value
Sea Hibiscus draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, sea hibiscus can only work that bloom inside District of Columbia's frost window — roughly 254 days, opening after the last 28°F freeze (Mar 15) and closing at the first (Nov 24), per NOAA Regional Climate Centers ACIS, 1991-2020.
District of Columbia Cooperative Extension
For District of Columbia-specific cultivar recommendations, planting calendars, and pest pressure for sea hibiscus, the canonical source is UDC Center for Urban Agriculture. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Sea Hibiscus native to District of Columbia?
No — the USDA PLANTS Database lists Sea Hibiscus as introduced rather than native in the Lower 48, so it is not part of District of Columbia's native flora. It grows here as a garden plant; pairing it with a few District of Columbia natives keeps local pollinators fed too.
Looking for plants that belong here? The District of Columbia 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 Sea Hibiscus in District of Columbia
When can I plant Sea Hibiscus in District of Columbia?
District of Columbia's last spring hard freeze (28°F) clears between Mar 15 and Mar 15, and the first fall hard freeze lands between Nov 24 and Nov 24 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Sea Hibiscus, so this page does not state whether it overwinters in District of Columbia 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 Sea Hibiscus grown in across District of Columbia?
District of Columbia spans USDA hardiness zones 7b-8a (USDA ARS PHZM 2023). Sea Hibiscus carries a range of zones 10-12, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical District of Columbia site have?
A typical District of Columbia site sees ~254 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Sea Hibiscus needs 270+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Sea Hibiscus native to District of Columbia?
No — the USDA PLANTS Database lists Sea Hibiscus as introduced rather than native in the Lower 48, so it is not part of District of Columbia's native flora. It grows here as a garden plant; pairing it with a few District of Columbia natives keeps local pollinators fed too.
How should I amend the soil for Sea Hibiscus in District of Columbia?
Sea Hibiscus prefers pH 5.5-7.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across District of Columbia soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Sea Hibiscus actually grow on my specific land in District of Columbia?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores sea hibiscus 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 District of Columbia
State-level data is a sketch. Your Growable Ground report scores sea hibiscus against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that District of Columbia sea hibiscus averages can't show:
We read public map data around District of Columbia — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the District of Columbia sea hibiscus average
Explore More
Growing guides for sea hibiscus
Explore District of Columbia county by county
District of Columbia carries 1 counties with their own USDA zone — a sample of the growing pages for sea hibiscus there:
Where else sea hibiscus grows
Sea Hibiscus's zone band crosses state lines — these are the states closest to District of Columbia 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 District of Columbia
District of Columbia has a growing page for 1,013 plants — a rotating sample of the rest of the shelf.
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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