Unlikely — Zone Mismatch
kangkong (zones 9-12) does not overlap with Pennsylvania's zone range (5b-8a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Kangkong is hardy to zone 9, and the warmest ground in Pennsylvania is zone 7 — 2 zones short. Planted in open ground it will not survive a Pennsylvania winter. To grow it here, grow kangkong under glass — a greenhouse is the only lift this wide the engine models.
A greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 9-12 (plant) against 5-7 (Pennsylvania). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
Pennsylvania spans zones 5b-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 kangkong 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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Zone Comparison
Kangkong Needs
- USDA Zones: 9-12
- Frost-Free Days: 30+
- Sun: Full Sun
- Mature size: 1.5 ft tall
- Picking window: ~45 days of harvest
- Drought tolerance: Low
Pennsylvania Has
- USDA Zones: 5b-8a
- Last Hard Freeze (28°F): Apr 6 - Apr 24
- First Hard Freeze (28°F): Oct 25 - Nov 3
- Annual Rainfall: 36-48 inches
- Common Soils: Silt loam, Shale-derived, Limestone-derived
Plant Zone Range (zones 9-12)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Kangkong in Pennsylvania
The frost window
Across Pennsylvania, the last spring hard freeze (28°F) clears between Apr 6 and Apr 24, and the first fall hard freeze lands between Oct 25 and Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 184-day window you can count on — up to 211 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 kangkong goes out, not when it starts. It is sown under cover about 4 weeks ahead, so counting back from Pennsylvania's late-side last freeze of Apr 24 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Winter standing
Pennsylvania runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for kangkong, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether kangkong is a permanent planting or a replant-every-spring crop for you turns on your own zone within Pennsylvania; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Potter County, not the statewide average.
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 kangkong does not survive a Pennsylvania 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 Pennsylvania under protection.
Frost-free days
Kangkong wants 30+ frost-free days; a typical Pennsylvania site sees ~197 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Kangkong needs ~1500 GDD (base 50°F) to ripen. The state median runs ~2447 GDD (from PRISM 1991-2020 climate normals), so Pennsylvania'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
Kangkong tolerates a wide pH range (pH 4.3-7.5) — 3.2 units, acid ground through alkaline — so soil acidity is rarely what limits it in Pennsylvania. 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 and 7 — worth knowing before you decide whether a Pennsylvania soil test result is a problem or just a number. Drainage requirement: poorly (saturated >50% of year). A soil-survey lookup (NRCS SSURGO) flags whether your specific site matches.
Your land, not the state average
Whether kangkong is safe to eat from Pennsylvania soil is a block-by-block question, not a town-wide one — 68,671 documented contamination sites mean levels spike on some parcels and not the one next door. Kangkong roots to about 7 inches, so it is the top 7 inches under your address that decide what it takes up, so only a test on your address settles it.
Check your parcel → Source: USDA NRCS SSURGO + EPA/state contamination databases.
Plant pH and drainage requirements from USDA PLANTS Database. Pennsylvania soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Kangkong in Pennsylvania — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 9-12 (USDA PLANTS Database)
- State Zones: 5b-8a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Apr 6 - Apr 24 to Oct 25 - Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 45 days
What Else to Consider for Kangkong in Pennsylvania
Zone compatibility tells you about winter cold survival — but Pennsylvania growers also need to think about:
Rocky shale soils in the ridge-and-valley region
Short mountain seasons in the Poconos and Alleghenies
Deer pressure is among the highest in the US
Growing kangkong here specifically
Kangkong is a leafy crop whose edible part grows in or against the soil and can take up lead, and Pennsylvania carries 68,671 documented contamination sites where legacy fill and old paint push metals up parcel by parcel.
Grow kangkong in raised beds of tested clean soil and run a parcel soil-lead test before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Pennsylvania grower, not just kangkong — is covered on the Pennsylvania growing guide.
Timing shifts within Pennsylvania
Pennsylvania isn't one climate. In Potter County, the last hard freeze (28°F) holds until about May 5 — roughly 21 days later than the recorded state median — so plant kangkong to your county's window, not the statewide date.
Kangkong needs about 30 days of frost-free season to complete its cycle. Even Potter County — Pennsylvania’s shortest season at 160 frost-free days — clears that by 130 days, so season length isn’t the constraint anywhere in Pennsylvania. What varies is your own parcel.
Across Pennsylvania’s 67 counties the frost-free season runs from 160 days in Potter County to 250 days in Philadelphia County — a spread of 90 days, which is why a single statewide planting date misleads. The median Pennsylvania county sees 197 frost-free days, leaving kangkong about 167 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"). Kangkong's 30-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
Kangkong draws honeybees (low value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, kangkong can only work that bloom inside Pennsylvania's frost window — roughly 197 days, opening after the last 28°F freeze (Apr 6 - Apr 24) and closing at the first (Oct 25 - Nov 3), per NOAA Regional Climate Centers ACIS, 1991-2020.
Pennsylvania Cooperative Extension
For Pennsylvania-specific cultivar recommendations, planting calendars, and pest pressure for kangkong, the canonical source is Penn State Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Kangkong native to Pennsylvania?
No — the USDA PLANTS Database lists Kangkong as introduced rather than native in the Lower 48, so it is not part of Pennsylvania's native flora. It grows here as a garden plant; pairing it with a few Pennsylvania natives keeps local pollinators fed too.
Looking for plants that belong here? The Pennsylvania 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 Kangkong in Pennsylvania
When can I plant Kangkong in Pennsylvania?
Pennsylvania's last spring hard freeze (28°F) clears between Apr 6 and Apr 24, and the first fall hard freeze lands between Oct 25 and Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Kangkong, so this page does not state whether it overwinters in Pennsylvania 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 Kangkong grown in across Pennsylvania?
Pennsylvania spans USDA hardiness zones 5b-8a (USDA ARS PHZM 2023). Kangkong carries a range of zones 9-12, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Pennsylvania site have?
A typical Pennsylvania site sees ~197 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Kangkong 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 Potter, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Kangkong native to Pennsylvania?
No — the USDA PLANTS Database lists Kangkong as introduced rather than native in the Lower 48, so it is not part of Pennsylvania's native flora. It grows here as a garden plant; pairing it with a few Pennsylvania natives keeps local pollinators fed too.
How should I amend the soil for Kangkong in Pennsylvania?
Kangkong tolerates pH 4.3-7.5 and poorly (saturated >50% of year) drainage (FAO ECOCROP). That is a 3.2-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Pennsylvania site — amend for drainage and organic matter first.
Will Kangkong actually grow on my specific land in Pennsylvania?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores kangkong 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 Pennsylvania
State-level data is a sketch. Your Growable Ground report scores kangkong against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Pennsylvania kangkong averages can't show:
We read public map data around Pennsylvania — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Pennsylvania kangkong average
Explore More
Growing guides for kangkong
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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