Yes — Strong Match
borage (zones 2-11) covers every zone Pennsylvania contains (5b-8a), so hardiness is not what limits it anywhere in the state.
Your yard isn't the whole zone.
Borage is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Pennsylvania site runs ~197 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score borage against your land's actual frost dates, sun, and soil.
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Zone Comparison
Borage Needs
- USDA Zones: 2-11
- Frost-Free Days: 150+
- Sun: Full Sun
- Mature size: 2 ft tall
- Picking window: ~60 days of harvest
- Drought tolerance: Medium
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 2-11)
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 Borage 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.
Frost tenderness
Borage is frost-tender — its listed minimum temperature is 39.2°F (USDA PLANTS Database) — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does.
When to start the seed
Borage is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Pennsylvania'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.
Days to maturity vs. the window
At 60 days to maturity (USDA PLANTS Database), counting from the last hard freeze it ripens with 124 days to spare even in Pennsylvania's tightest freeze scenario — room for a later start or a second sowing.
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 borage survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Borage wants 150+ frost-free days; a typical Pennsylvania site sees ~197 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a workable window — start indoors to bank time.
Growing degree days
Borage needs ~900 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
Borage likes near-neutral soil (pH 6-8.3). That's the common-ground band across Pennsylvania's silt loam and shale-derived — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6.5 and 7.5 — worth knowing before you decide whether a Pennsylvania soil test result is a problem or just a number. 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
SSURGO maps about 14.1% of Pennsylvania as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Borage sits mid-range for drought tolerance, so either extreme can cost you — 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.
Borage in Pennsylvania — Quick Answer
- Verdict: Yes — Strong Match
- Plant Zones: 2-11 (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: 60 days
What Else to Consider for Borage 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 borage here specifically
Borage likes pH 6.0–8.3 and takes cold to about 39°F, yet neither saves it from wet feet — SSURGO maps about 14.1% of Pennsylvania poorly-drained, where its crown sit and rot.
Set borage high on bermed, grit-amended ground so winter and storm water drain away from the crown. How to handle it →
What to actually do about these — and the constraints that apply to every Pennsylvania grower, not just borage — 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 borage to your county's window, not the statewide date.
Borage needs about 150 days of frost-free season to complete its cycle. Even Potter County — Pennsylvania’s shortest season at 160 frost-free days — clears that by 10 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 borage about 47 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"). Borage's 150-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Where in Pennsylvania Fits Best
Even within Pennsylvania's zones 5b-8a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for borage (USDA PHZM 2023):
Pollinator + Wildlife Value
Borage draws honeybees and native bees (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, borage 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.
Recommended Borage Varieties for Pennsylvania
Pennsylvania publishes no state variety trial for borage, so we won't invent a "best for Pennsylvania" list. Choose types rated to your USDA hardiness zone (5b-8a), and confirm winter survival and drainage against your own parcel.
Pennsylvania Cooperative Extension
For Pennsylvania-specific cultivar recommendations, planting calendars, and pest pressure for borage, the canonical source is Penn State Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Borage native to Pennsylvania?
No — the USDA PLANTS Database lists Borage 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 Borage in Pennsylvania
When can I plant Borage 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). Borage is frost-tender — its listed minimum temperature is 39.2°F (USDA PLANTS Database) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.
Can Borage mature before first frost in Pennsylvania?
Yes — Borage matures in 60 days (USDA PLANTS Database), and Pennsylvania's dependable hard-freeze-free window runs 184 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 124 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.
What hardiness zone is Borage grown in across Pennsylvania?
Pennsylvania spans USDA hardiness zones 5b-8a (USDA ARS PHZM 2023). Borage carries a range of zones 2-11, 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). Borage needs 150+ 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 Borage native to Pennsylvania?
No — the USDA PLANTS Database lists Borage 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 Borage in Pennsylvania?
Borage prefers pH 6-8.3 and well (dry spells) drainage (FAO ECOCROP). 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 Borage actually grow on my specific land in Pennsylvania?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores borage 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 borage against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Pennsylvania borage 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 borage average
Explore More
Growing guides for borage
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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