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USDA Hardiness Zone 5b

Frost Dates for 49680 — South Boardman, Michigan

Averages from S Boardman 2w, Mi US, the nearest reporting station, 3.3 miles away.

Plant tender crops after May 24, and expect the first autumn freeze around October 4. That leaves about 133 frost-free days.

Last spring frost
May 24

50% probability

First fall frost
October 4

50% probability

Growing season
133 days

frost-free

Hardiness zone
5b

-15 to -10°F annual low

Planting calendar for 49680

What to do and when, based on the frost normals for South Boardman, Michigan
WhenWhat to do
March 15 – March 29

Start peppers and aubergines indoors

They need eight to ten weeks under lights before they can go out.

March 29 – April 12

Start tomatoes indoors

Six to eight weeks gives a transplant big enough to set fruit early.

April 26 – May 10

Sow peas, spinach, lettuce, radish outdoors

These tolerate light frost and prefer to germinate in cool soil.

May 24 onward

Transplant tomatoes, peppers, basil, squash, cucumbers

The average last freeze has passed — still watch the actual forecast.

by July 12

Sow the autumn crop of carrots, beets and brassicas

They need about twelve weeks to size up before growth stops.

by September 20

Harvest tender crops, or be ready to cover them

A first freeze two weeks early is well within normal variation.

October 4 onward

Plant garlic, mulch beds, lift tender bulbs

Garlic wants a cold spell; bare soil loses structure over winter.

What these dates mean

Wait until after May 24 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in South Boardman, Michigan are past their last freeze. Harvest before October 4, which leaves roughly 133 frost-free days.

ZIP 49680 sits in USDA hardiness zone 5b, meaning the average coldest night of the year falls between -15 to -10°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.

These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.

Other zone 5b ZIP codes in Michigan