Can I Grow Hollyhock in Pennsylvania?

Hollyhock in Pennsylvania — the short answer

Pennsylvania is not one climate

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 hollyhock (USDA PHZM 2023):

Zone Comparison

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 Hollyhock in Pennsylvania

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

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.

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. Pennsylvania soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Hollyhock in Pennsylvania

Zone compatibility tells you about winter cold survival — but Pennsylvania growers also need to think about:

What to actually do about these — and the constraints that apply to every Pennsylvania grower, not just hollyhock — is covered on the Pennsylvania growing guide.

Where in Pennsylvania Hollyhock Is Zone-Hardy

Hollyhock is rated for USDA zones 5–9. Every one of Pennsylvania’s 67 counties sits inside that band — from Cambria County at zone 5b to Philadelphia County at zone 7b — so winter cold is not what decides this plant anywhere in the state. What is left to vary is your own parcel: slope, shelter and cold-air drainage routinely move a site half a zone either way from the county figure.

Across those 67 counties Pennsylvania’s winter-low ladder runs from zone 5b in Cambria County to zone 7b in Philadelphia County — 2 USDA zones of spread, which is 20°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. Potter County holds its last hard freeze (28°F) until about May 5, while Philadelphia County is clear by Mar 19 — 47 days apart. Set hollyhock 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". Hollyhock’s zone 5–9 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

Hollyhock draws honeybees, native bees, butterflies, and hummingbirds (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, hollyhock 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 hollyhock, the canonical source is Penn State Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Hollyhock native to Pennsylvania?

No — the USDA PLANTS Database lists Hollyhock 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.

What pests threaten hollyhock in Pennsylvania?

Japanese beetle is documented in Pennsylvania and will find hollyhock, but it is manageable here. What an experienced grower watches for, and does:

Japanese beetle

Worth watching

This is on the University of Minnesota's list of Japanese beetle preferred plants — but their read is that fruits, vegetables and herbs tolerate limited leaf feeding, and that in most cases the damage is cosmetic and will not kill the plant.

What to do: Protect it only through the few peak weeks: handpick into soapy water in the cool of morning, harvest regularly through July and August to take the feeding pressure off the edible parts, and keep the plant well watered — a vigorous plant outgrows feeding that looks worse than it is. Do not hang a beetle trap.

Documented range: states listed as Japanese-beetle infested · University of Minnesota Extension, National Plant Board

The full japanese beetle playbook

Only pests whose documented range and host relationship both trace to a primary source appear here — so a quiet section means we have nothing sourced to tell you, not that your garden is pest-free.

Common Questions About Growing Hollyhock in Pennsylvania