When to plant / Illinois
When to plant garlic in Illinois
The planting chart is divided into Northern Illinois, Central Illinois, and Southern Illinois. Median dates for the last 32-degree freeze on the same page: Northern Illinois April 8-29; Central Illinois April 8-15; Southern Illinois April 1-8. The page also says southern Illinois can generally start crops two weeks earlier than central Illinois and northern Illinois about two weeks later; the crop rows below are the chart dates, not a recalculation of that sentence.
Source: University of Illinois Extension, When to Plant, retrieved 2026-10-10.
How this page reads that source: Best planted in the fall. Illinois Fruit and Vegetable Planting Dates chart: north: Mid-September; central: October; south: Late October.
North
- Mid-September — printed phrase, not converted into a day range
Central
- October (October 1–October 31). The guide gives months, so the dated range uses the first day through the last day of those months.
South
- Late October — printed phrase, not converted into a day range
City frost pages in Illinois are listed on Illinois.