Michigan Field Tomatoes Peak in August and September

Michigan-grown tomatoes are at their prime in August and September, according to Michigan State University Extension. Slicing tomatoes, cherry and grape tomatoes, Roma and other paste varieties, and heirlooms can all appear during that window.

Weather changes the timing. The Michigan Lower Peninsula availability guide is a planning tool, not a guarantee that a particular vendor will have a particular variety.

Where to look locally

The Ann Arbor Farmers Market operates Wednesdays and Saturdays from 7 a.m. to 3 p.m. from May through December. Vendor attendance and inventory vary, so ask who grew the tomatoes and where.

The Washtenaw County farmers market finder lists additional markets in Ann Arbor, Ypsilanti, Dexter, Chelsea, Saline, Pittsfield Township, Manchester, and elsewhere in the county.

Choosing and storing tomatoes

MSU Extension recommends firm, disease-free tomatoes for canning. It also notes that yellow tomatoes are not necessarily lower in acid than red tomatoes, an important correction to a common assumption.

For fresh use, allow tomatoes to ripen at room temperature. MSU's growing and storage guidance warns that tomatoes are sensitive to chilling injury and should not be stored below 50 degrees Fahrenheit while ripening.

Use slicing tomatoes for sandwiches and salads. Paste tomatoes have less free liquid and work efficiently in sauce. Cherry and grape tomatoes can be eaten raw or roasted.

Preservation requires a tested recipe

Tomatoes sit close enough to the acidity boundary that safe canning instructions matter. MSU Extension's tomato bulletin gives tested acidification and processing guidance. Do not improvise jar size, acid quantity, or processing time.

Fresh tomato season is forgiving in the kitchen. Canning is not. Use the extension recipe exactly.