What to plant in December in Wisconsin
In Wisconsin (WI), December sits about 21 weeks before the average last frost (May 10). The state averages 143 frost-free days a year (last frost May 10, first frost September 30; USDA zones 3b, 4a, 4b, 5a, 5b).
Almost nothing is due to be sown in December - it's a month for planning, ordering seed and looking after what's already growing.
Dates here come from Wisconsin frost dates (last frost May 10, first frost Sep 30). For one crop in detail, see when to plant tomato, lettuce or garlic in Wisconsin.
Wisconsin: planting activity through the year
Planting dates for popular crops in Wisconsin
Every crop has its own full-year dates for Wisconsin: indoor start, transplant or direct sowing, and harvest.
Spring bulbs to plant in December in Wisconsin
Plant when the ground cools to about 50-55°F or lower (but is not frozen), and keep planting until a couple of weeks before the ground freezes. (University of Wisconsin Extension) ↗
A planning month: December garden jobs in Wisconsin
- Order seed while stock is good. Wisconsin's average last frost is May 10, so the first indoor sowings begin around February 15 - see starting seeds indoors.
- Sketch this year's beds and move each crop family to a new spot - the garden planner and the crop rotation guide make it quick.
- Test old seed: roll ten seeds in a damp paper towel for a week. If fewer than seven sprout, sow thicker or buy fresh.
- If the ground isn't frozen, spread compost now so it's worked in by spring, and send off a soil test - December is when labs are quiet.
USDA zone chart for Wisconsin
Wisconsin spans USDA zones 3b, 4a, 4b, 5a, 5b. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.
Questions gardeners ask
What vegetables can I plant in Wisconsin in December?
Very little is sown outdoors in Wisconsin in December. Use the month to plan beds, order seed and prepare soil.
Is it too late to plant tomatoes in Wisconsin in December?
For this year, yes - the tomato windows in Wisconsin have closed. The next step is to start seeds indoors from about March 15.
Is it too late to plant lettuce in Wisconsin in December?
For this year, yes - the lettuce windows in Wisconsin have closed. The next step is to start seeds indoors from about April 5.
When is the first frost in Wisconsin?
The statewide average first fall frost is around September 30 and the last spring frost around May 10. Your town can be a week or two either side - look yours up by ZIP code.
When should I plant spring bulbs in Wisconsin?
Plant when the ground cools to about 50-55°F or lower (but is not frozen), and keep planting until a couple of weeks before the ground freezes. (University of Wisconsin Extension). See the bulb planting guide for depth and spacing.
What to plant in December in other states
Dates are computed from Wisconsin’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.