When Is The Last Frost Before Spring Gardening Can Start In Wisconsin?

MILWAUKEE, WI — Some big dates are approaching for the gardners of southeastern Wisconsin. But the big question for people itching to get their hands in the dirt: When will the danger of frost go away, making it safe to begin planting?

The Old Farmer’s Almanac offers a handy tool to find the average date of the last frost by city and state, right down to the ZIP code. In Milwaukee, the final day of frost tends to be around April 25 .

Bear in mind, this isn’t a fail-safe date. It’s based on historical climate data from the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information, and the probability of a frost after the average date is about 30 percent.

The publication, which has advised readers how and when to grow things since 1792, also has a 2023 planting guide calculator that allows Wisconsin gardeners to narrow down when they should be putting different vegetables in the ground.

Some plants to start early in southeastern Wisconsin's growing season are broccoli, cabbage, cauliflower and more. As the growing season progresses, people will be able to plant things like cantaloupe, lettuce, plus several types of herbs.

Another good resource for gardeners is the University of Wisconsin-Madison Extension. The scientists and specialists experience the same gardening challenges when it comes to weather conditions and pest management, and can provide geographically specific advice to plant what food crops.

Interest in growing their own food was increasing among Americans before the pandemic, but one analysis of Census Bureau and gardening industry sales data found an estimated 18.3 million people, most of them millennials, became first-time gardeners during the pandemic. Another survey suggests new gardeners are here to stay.

Some of those new and existing gardeners grew their vegetables in containers placed in sunny locations on decks, balconies and other open-air spaces. Almost anything that grows in the ground can be put in a pot.

The same frost dates apply. Some plants, like asparagus, can live and produce for 20 years, according to Harvest to Table, which offers practical guides to gardening no matter the setting.