Conditional — Some Areas
plumbago (zones 9-11) reaches only part of North Carolina (6a-9a): zone 9 are in range, so where you are in the state decides it.
One zone short — what would close it
Plumbago is hardy to zone 9, and the warmest ground in North Carolina is zone 8 — 1 zone short. Planted in open ground it will not survive a North Carolina winter. To grow it here, grow plumbago in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 9-11 (plant) against 6-8 (North Carolina). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
Plumbago in North Carolina — the short answer
Plumbago in North Carolina: hardy in zones 9–11, full sun, against a state median of ~245 frost-free days.
- Plant zones
- 9-11
- 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
- North Carolina zones
- 6a-9a
- USDA PHZM 2023
- Frost window
- Mar 11 - Mar 24 – Nov 10 - Nov 25
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 178 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.
North Carolina spans zones 6a-9a, 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 plumbago 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.
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North Carolina is not one climate
North Carolina’s winter-low ladder runs across 100 counties, from zone 6.5 in Avery County to zone 9 in Dare County. That is 25°F between the two counties’ average coldest night — the difference between plumbago overwintering in the ground and coming under cover.
The middle half of 100 counties runs 7.5–8 zones, with a median of 8 zones — a 2.5-zone span end to end.
Measured across 100 North Carolina counties. USDA PHZM 2023, per county. 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 North Carolina Fits Best
Plumbago is rated for zones 9–11 — a cold floor USDA puts at 20 to 30°F. Against North Carolina’s 100 counties that band holds in 1 of them, and the line runs at Dare County (zone 9a), the coldest county still inside it.
Inside zones 9–11
1 county
0 of 1 shown
Below the zone 9 floor
99 counties
- Avery County · zone 6b
- Swain County · zone 6b
- Watauga County · zone 6b
3 of 99 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 North Carolina's zones 6a-9a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for plumbago (USDA PHZM 2023):
Zone Comparison
Plumbago Needs
- USDA Zones: 9-11
- Sun: Full Sun
- Mature size: 6 ft tall
- Picking window: ~120 days of harvest
- Drought tolerance: High
North Carolina Has
- USDA Zones: 6a-9a
- Last Hard Freeze (28°F): Mar 11 - Mar 24
- First Hard Freeze (28°F): Nov 10 - Nov 25
- Annual Rainfall: 40-60 inches
- Common Soils: Red clay (Piedmont), Sandy loam (Coastal), Mountain loam
Plant Zone Range (zones 9-11)
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 Plumbago in North Carolina
The frost window
Across North Carolina, the last spring hard freeze (28°F) clears between Mar 11 and Mar 24, and the first fall hard freeze lands between Nov 10 and Nov 25 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 231-day window you can count on — up to 259 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
North Carolina runs as cold as USDA zone 6, and no sourced winter-hardiness floor is on record for plumbago, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether plumbago is a permanent planting or a replant-every-spring crop for you turns on your own zone within North Carolina; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Swain 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.
Soil + Drainage Fit
Plumbago likes near-neutral soil (pH 5.5-7). That's the common-ground band across North Carolina's red clay (piedmont) and sandy loam (coastal) — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 6.5 — worth knowing before you decide whether a North Carolina soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your North Carolina site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
North Carolina's soils run mostly fine sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for plumbago is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how plumbago 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. North Carolina soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Plumbago in North Carolina
Zone compatibility tells you about winter cold survival — but North Carolina growers also need to think about:
Red Piedmont clay is hard to work and drains poorly
Humidity drives significant disease pressure
Hurricane risk on the coastal plain
Growing plumbago here specifically
North Carolina's soils run mostly fine sandy loam (Ultisols), and whether that suits plumbago's pH 5.5–7.0 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward plumbago's 5.5–7.0 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every North Carolina grower, not just plumbago — is covered on the North Carolina growing guide.
Timing shifts within North Carolina
North Carolina isn't one climate. In Swain County, the last hard freeze (28°F) holds until about Apr 27 — roughly 41 days later than the recorded state median — so plant plumbago to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in North Carolina Plumbago Is Zone-Hardy
Plumbago is rated for USDA zones 9–11. 1 of North Carolina’s 100 counties fall inside that band. The coldest that does is Dare County at zone 9a. 99 counties sit below the plant’s zone 9 floor, where an unprotected plant is relying on snow cover and a mild year. Where you are in North Carolina decides this one.
Across those 100 counties North Carolina’s winter-low ladder runs from zone 6b in Avery County to zone 9a in Dare County — 2.5 USDA zones of spread, which is 25°F between the two counties’ average coldest night of the year. That is why a statewide hardiness answer is where you start and not where you finish.
The planting window moves with it. Swain County holds its last hard freeze (28°F) until about Apr 27, while Dare County is clear by Feb 18 — 68 days apart. Set plumbago out on your county’s date, not the state’s.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F killing freeze — earlier than the folk 32°F "last frost". Plumbago’s zone 9–11 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
Plumbago draws honeybees and butterflies (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, plumbago can only work that bloom inside North Carolina's frost window — roughly 245 days, opening after the last 28°F freeze (Mar 11 - Mar 24) and closing at the first (Nov 10 - Nov 25), per NOAA Regional Climate Centers ACIS, 1991-2020.
Recommended Plumbago Varieties for North Carolina
North Carolina publishes no state variety trial for plumbago, so we won't invent a "best for North Carolina" list. Choose types rated to your USDA hardiness zone (6a-9a), and confirm winter survival and drainage against your own parcel.
North Carolina Cooperative Extension
For North Carolina-specific cultivar recommendations, planting calendars, and pest pressure for plumbago, the canonical source is NC State Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Plumbago native to North Carolina?
No — the USDA PLANTS Database lists Plumbago as introduced rather than native in the Lower 48, so it is not part of North Carolina's native flora. It grows here as a garden plant; pairing it with a few North Carolina natives keeps local pollinators fed too.
Looking for plants that belong here? The North Carolina 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 Plumbago in North Carolina
When can I plant Plumbago in North Carolina?
North Carolina's last spring hard freeze (28°F) clears between Mar 11 and Mar 24, and the first fall hard freeze lands between Nov 10 and Nov 25 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Plumbago, so this page does not state whether it overwinters in North Carolina 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 Plumbago grown in across North Carolina?
North Carolina spans USDA hardiness zones 6a-9a (USDA ARS PHZM 2023). Plumbago carries a range of zones 9-11, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical North Carolina site have?
A typical North Carolina site sees ~245 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Plumbago 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. In cooler counties like Swain, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Plumbago native to North Carolina?
No — the USDA PLANTS Database lists Plumbago as introduced rather than native in the Lower 48, so it is not part of North Carolina's native flora. It grows here as a garden plant; pairing it with a few North Carolina natives keeps local pollinators fed too.
How should I amend the soil for Plumbago in North Carolina?
Plumbago prefers pH 5.5-7 and well (dry spells) drainage (Growable Ground Plant Database). That sits in the common-ground band across North Carolina soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Plumbago actually grow on my specific land in North Carolina?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores plumbago 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 North Carolina
State-level data is a sketch. Your Growable Ground report scores plumbago against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that North Carolina plumbago averages can't show:
We read public map data around North Carolina — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the North Carolina plumbago average
Explore More
Growing guides for plumbago
Explore North Carolina county by county
North Carolina carries 100 counties with their own USDA zone — a sample of the growing pages for plumbago there:
Where else plumbago grows
Plumbago's zone band crosses state lines — these are the states closest to North Carolina 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 North Carolina
North Carolina has a growing page for 1,020 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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