What to plant in December in Illinois
In Illinois (IL), December sits about 18 weeks before the average last frost (April 20). The state averages 177 frost-free days a year (last frost April 20, first frost October 14; USDA zones 5a, 5b, 6a, 6b, 7a).
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 Illinois frost dates (last frost Apr 20, first frost Oct 14). For one crop in detail, see when to plant tomato, lettuce or garlic in Illinois.
Illinois: planting activity through the year
Planting dates for popular crops in Illinois
Every crop has its own full-year dates for Illinois: indoor start, transplant or direct sowing, and harvest.
Spring bulbs to plant in December in Illinois
Tulips, daffodils, hyacinths and crocus are planted in fall, once the soil has cooled and before it freezes. The exact window depends on the state, so our bulb guide quotes what each extension service says.
A planning month: December garden jobs in Illinois
- Order seed while stock is good. Illinois's average last frost is April 20, so the first indoor sowings begin around January 26 - 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 Illinois
Illinois spans USDA zones 5a, 5b, 6a, 6b, 7a. 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 Illinois in December?
Very little is sown outdoors in Illinois in December. Use the month to plan beds, order seed and prepare soil.
Is it too late to plant tomatoes in Illinois in December?
For this year, yes - the tomato windows in Illinois have closed. The next step is to start seeds indoors from about February 23.
Is it too late to plant lettuce in Illinois in December?
For this year, yes - the lettuce windows in Illinois have closed. The next step is to start seeds indoors from about March 16.
When is the first frost in Illinois?
The statewide average first fall frost is around October 14 and the last spring frost around April 20. Your town can be a week or two either side - look yours up by ZIP code.
What to plant in December in other states
Dates are computed from Illinois’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.