When to Plant in Wisconsin

Wisconsin's cold climate means a shorter growing season, but experienced gardeners make every week count. Last frost dates range from early May in the south to early June in the north, and first fall frosts can arrive as early as mid-September in northern areas.

Despite the short season, Wisconsin's rich soils and long summer days produce excellent harvests. Cool-season crops like lettuce, peas, and root vegetables thrive here, and warm-season crops do well with proper timing and season extension techniques.

Common Mistakes

Planting warm-season crops before late May — even southern Wisconsin can get frost into mid-May.
Not using cold frames, row covers, or hoop houses — season extension is key in Wisconsin.
Choosing late-maturing varieties — stick with short-season varieties (especially for tomatoes and peppers).
Ignoring soil temperature — cold soil rots seeds; wait until soil reaches 50-60°F for most crops.

FAQ

What is the last frost date?

The last frost date is the typical date in spring when your area has its final frost. After this date, it's generally safe to plant warm-season crops outdoors.

When should I start tomatoes indoors in Wisconsin?

Start tomato seeds indoors about 6–8 weeks before your last frost date. For most of Wisconsin, that means starting seeds in late March to mid-April.

Can I plant before the last frost?

Yes — cool-season crops like lettuce, peas, spinach, and broccoli can handle light frost and should be planted 4–6 weeks before your last frost date.

Why does timing vary so much within Wisconsin?

Southern Wisconsin near Madison and Milwaukee is notably warmer than the northern part of the state. Lake Michigan also moderates eastern shore temperatures.

What if I live in a frost-free area?

Wisconsin doesn't have frost-free areas. The Madison and Milwaukee areas have the longest seasons. Season extension tools like cold frames can help. Enter your zip code for exact dates.

How does Plan My Garden create my schedule?

You enter your zip code, and we look up your local frost dates. Then based on the crops you pick, we calculate when to start seeds, transplant, and harvest — personalized to your location.