Conditional — Some Areas
rhubarb (zones 2-8) has limited zone overlap with Pennsylvania (5a-7a). Only zones 5-7 in the state are suitable.
Your yard isn't the whole zone.
Pennsylvania spans zones 5a-7a, 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 rhubarb against your land's actual soil, sun, and frost.
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
Rhubarb Needs
- USDA Zones: 2-8
- Soil pH: 5.3 - 7.8
- Sun: Full Sun
- Drainage: well (dry spells)
- Frost-Free Days: 60+
Pennsylvania Has
- USDA Zones: 5a-7a
- Last Frost: Apr 10 - May 15
- First Frost: Sep 25 - Oct 25
- Annual Rainfall: 36-48 inches
- Common Soils: Silt loam, Shale-derived, Limestone-derived
Plant Zone Range (zones 2-8)
Preferred Soil pH
Plant data: USDA PLANTS Database / plant_species_v5.csv. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Rhubarb in Pennsylvania
The frost window
Across Pennsylvania, the last spring frost clears between Apr 10 and May 15, and the first fall frost lands between Sep 25 and Oct 25 (NOAA Climate Normals 1991-2020). Counting from the latest last frost to the earliest first frost, that's a 133-day window you can count on — up to 198 days on a mild site in a kind year.
Frost tenderness
Rhubarb is frost-tender — its listed minimum temperature is 41°F (USDA PLANTS Database) — so set plants out after the last frost has cleared your local site, not the state's earliest date.
Establishment timing
As a long-lived plant, rhubarb isn't racing the calendar to a harvest date. Plant it in spring once the last-frost window passes so roots settle in through the full season, or in early fall while the soil still holds summer warmth.
Timing tuned to sub-state frost dates — McKean 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
Zone compatibility says you can survive winter here. Whether the growing season is long enough — and warm enough — is a different question.
Frost-free days
Rhubarb wants 60+ frost-free days; a typical Pennsylvania site sees ~190 (NOAA Climate Normals). That leaves comfortable headroom for succession planting.
Growing degree days
Rhubarb needs ~800 GDD (base 50°F) to ripen. The state median runs ~3200 GDD (USDA NRCS county aggregates), so Pennsylvania's typical season clears that easily.
Climate aggregates derive from USDA NRCS county-level hardiness data + Cornell CALS Extension GDD-by-region tables + MSU Extension chill-hours-by-zone (1991-2020 NOAA Climate Normals baseline).
Soil + Drainage Fit
Rhubarb likes near-neutral soil (pH 5.3-7.8). That's the common-ground band across Pennsylvania's silt loam and shale-derived — a soil test confirms it for your site. Drainage matters: this plant wants well (dry spells). If your Pennsylvania site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Whether rhubarb thrives in Pennsylvania comes down to drainage, and SSURGO drainage class flips from well-drained to poorly-drained parcel to parcel — your soil map unit, not the state average, is the real answer.
Check your parcel → Source: USDA NRCS SSURGO.
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.
Rhubarb in Pennsylvania — Quick Answer
- Verdict: Conditional — Some Areas
- Plant Zones: 2-8 (USDA PLANTS Database)
- State Zones: 5a-7a (USDA ARS PHZM 2023)
- Growing Season: Apr 10 - May 15 to Sep 25 - Oct 25 (NOAA Climate Normals)
- Days to Maturity: 730 days
What Else to Consider
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
Build up over shale rather than into it — raised beds with imported soil give roots depth the ridge won't.
Short mountain seasons in the Poconos and Alleghenies
Mountain growers stretch the season with cold frames and fast varieties — the missing weeks are recoverable.
Deer pressure is among the highest in the US
In the hardest-hit deer country, a tall fence is the only reliable line — resistant plants cover the rest.
Growing rhubarb here specifically
Rhubarb rates to USDA zones 2–8 and is hardy to about 41°F, but cold isn't the risk in Pennsylvania — wet is: with roughly 14.1% of its soils poorly-drained (SSURGO), soggy ground rots the roots.
Give rhubarb a raised bed or mounded row with coarse amendment so its roots never sit wet. How to handle it →
Timing shifts within Pennsylvania
Pennsylvania isn't one climate. In McKean County, the last hard freeze (28°F) holds until about Apr 16 — roughly 15 days later than the recorded state median — so plant rhubarb to your county's window, not the statewide date.
County last-freeze dates: NOAA/PRISM Climate Normals 1991-2020, 28°F threshold (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Good to Know Before You Plant Rhubarb
Rhubarb is listed as toxic to dogs, cats (leaves) at a moderate level (ASPCA). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.
Pennsylvania Cooperative Extension
For Pennsylvania-specific cultivar recommendations, planting calendars, and pest pressure for rhubarb, the canonical source is Penn State Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Rhubarb native to Pennsylvania?
No — the USDA PLANTS Database lists Rhubarb 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 Rhubarb in Pennsylvania
When can I plant Rhubarb in Pennsylvania?
Pennsylvania's last spring frost clears between Apr 10 and May 15, and the first fall frost lands between Sep 25 and Oct 25 (NOAA Climate Normals 1991-2020). Rhubarb is a long-lived planting, so target spring just after your local last frost — or early fall while the soil holds warmth — and let it establish through the season.
What hardiness zone is Rhubarb grown in across Pennsylvania?
Pennsylvania spans USDA hardiness zones 5a-7a (USDA ARS PHZM 2023). Rhubarb carries a range of zones 2-8, 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 ~190 frost-free days per year (derived from NOAA Climate Normals 1991-2020). Rhubarb needs 60+ 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 McKean, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Rhubarb native to Pennsylvania?
No — the USDA PLANTS Database lists Rhubarb 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 Rhubarb in Pennsylvania?
Rhubarb prefers pH 5.3-7.8 and well (dry spells) drainage (USDA PLANTS Database). That sits in the common-ground band across Pennsylvania soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Rhubarb actually grow on my specific land in Pennsylvania?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores rhubarb 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 rhubarb against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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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 →