Wisconsin planting calendar

When to plant parsley in Wisconsin — sow, transplant & harvest dates

Wisconsin is mostly USDA zone 5a (range 3b-6a). Dates below are derived from parsley's frost tolerance and Wisconsin's frost window — not generic national averages.

Parsley planting timetable for Wisconsin

Stage	When in Wisconsin	Anchor
Start seeds indoors	early March (March 6)	10 weeks before the last frost (mid-May)
Transplant outside	late April (April 24)	21 days before the last frost (mid-May)
First harvest (estimate)	early July (July 8)	~75 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 Wisconsin's climate shifts the parsley dates

Wisconsin's last spring frost averages mid-May and first fall frost early October, which sets the whole planting clock. Wisconsin is a cold, continental Midwest state, milder along Lake Michigan and considerably colder in the northern interior. Sow early — parsley bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

Parsley is notoriously slow to germinate — 14-28 days at optimal temperatures — which is why indoor starting 10-12 weeks before the last frost is worthwhile despite its mild transplant tolerance. Established plants are half-hardy and can go outside 3-4 weeks before the last spring frost, surviving temperatures down to about -6 °C (20 °F). Being a biennial, parsley produces leaves all through its first season, then bolts and flowers in its second year; in zones 7 and warmer it often overwinters successfully in the ground.

Frost-risk note

Don't plant before mid-May — a hard freeze can still set young plants back. In the north-central highlands near the UP line (zone 3b) the safe date runs a week or two later.

Regional variation within Wisconsin

the north-central highlands near the UP line (zone 3b) runs roughly 1-2 weeks behind the state average; the Lake Michigan shore around Milwaukee (zone 6a) can plant 1-2 weeks earlier.

Milwaukee — USDA zone 6a
Madison — USDA zone 5b
Green Bay — USDA zone 5a
Eau Claire — USDA zone 4b

What else to plant in Wisconsin around then

The same early window suits peas, lettuce, spinach, and onion sets.

Quick-grow guide

Sun: Full sun to partial shade — 4-6 hours direct.
Soil temperature for germination: 13-24 °C (55-75 °F).
Spacing: 6-9 inches (15-23 cm) between plants.
Days to harvest: ~75 days from planting out.

Frequently asked questions

When is the best time to plant parsley in Wisconsin?

In Wisconsin (mostly USDA zone 5a), sow parsley indoors around early March, transplant outdoors late April (before the last frost, mid-May), and harvest from early July. Parsley are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

What USDA zone is Wisconsin?

Most of Wisconsin sits in USDA hardiness zone 5a, with the state spanning roughly 3b-6a from the north-central highlands near the UP line (zone 3b) to the Lake Michigan shore around Milwaukee (zone 6a). The last spring frost averages mid-May and the first fall frost early October.

Can you grow parsley in Wisconsin?

Yes. Wisconsin's dominant zone 5a supports parsley — the key is timing. Parsley are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

Does the planting date change across Wisconsin?

the north-central highlands near the UP line (zone 3b) runs roughly 1-2 weeks behind the state average; the Lake Michigan shore around Milwaukee (zone 6a) can plant 1-2 weeks earlier.

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

The same early window suits peas, lettuce, spinach, and onion sets.

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.