Pennsylvania planting calendar

When to plant oregano in Pennsylvania — sow, transplant & harvest dates

Pennsylvania is mostly USDA zone 6b (range 5a-7b). Dates below are derived from oregano's frost tolerance and Pennsylvania's frost window — not generic national averages.

Oregano planting timetable for Pennsylvania

Stage	When in Pennsylvania	Anchor
Start seeds indoors	mid-March (March 14)	6 weeks before the last frost (late April)
Transplant outside	late April (April 25)	0 days after the last frost (late April)
First harvest (estimate)	mid-July (July 14)	~80 days from transplant

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why Pennsylvania's climate shifts the oregano dates

Pennsylvania's last spring frost averages late April and first fall frost mid-October, which sets the whole planting clock. Pennsylvania runs from cold northern mountains to a mild southeastern corner. Philadelphia gardens almost two zones warmer than the northern tier. Wait for warm soil — oregano stall in cold ground even after the air warms, so don't rush them out.

Oregano is a hardy perennial in zones 5-10 and is easiest to start from seed indoors 6-8 weeks before the last spring frost, or from divisions or cuttings; seeds are tiny and slow to produce harvestable growth. Transplant outdoors around the last frost date once soil has warmed to at least 13 °C — established plants tolerate light frost. In zones 4 and colder, treat as an annual or overwinter divisions in a cold frame; in zones 9-11 it stays evergreen but may die back in intense summer heat without afternoon shade.

Frost-risk note

Don't plant before late April — a hard freeze can still set young plants back. In the northern Allegheny plateau (zone 5a) the safe date runs a week or two later.

Regional variation within Pennsylvania

the northern Allegheny plateau (zone 5a) runs roughly 1-2 weeks behind the state average; the southeast around Philadelphia (zone 7b) can plant 1-2 weeks earlier.

Philadelphia — USDA zone 7b
Pittsburgh — USDA zone 6b
Harrisburg — USDA zone 7a
Allentown — USDA zone 6b
Erie — USDA zone 6b

What else to plant in Pennsylvania around then

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 13-21 °C (55-70 °F).
Spacing: 8-12 inches (20-30 cm) between plants.
Days to harvest: ~80 days from planting out.

Frequently asked questions

When is the best time to plant oregano in Pennsylvania?

In Pennsylvania (mostly USDA zone 6b), sow oregano indoors around mid-March, transplant outdoors late April (after the last frost, late April), and harvest from mid-July. Oregano are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

What USDA zone is Pennsylvania?

Most of Pennsylvania sits in USDA hardiness zone 6b, with the state spanning roughly 5a-7b from the northern Allegheny plateau (zone 5a) to the southeast around Philadelphia (zone 7b). The last spring frost averages late April and the first fall frost mid-October.

Can you grow oregano in Pennsylvania?

Yes. Pennsylvania's dominant zone 6b supports oregano — the key is timing. Oregano are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

Does the planting date change across Pennsylvania?

the northern Allegheny plateau (zone 5a) runs roughly 1-2 weeks behind the state average; the southeast around Philadelphia (zone 7b) can plant 1-2 weeks earlier.

What else can I plant in Pennsylvania around the same time?

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.