When to Plant Garlic in Illinois
Plant in fall, harvest in summer. Garlic is one of the most rewarding crops for the patient gardener.
The Short Answer
Illinois Frost Dates
Your planting dates depend on which part of Illinois you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Illinois (Chicago) | 5a, 5b | Apr 25 - May 10 | Oct 1 - Oct 15 |
| Central Illinois | 5b, 6a | Apr 15 - May 1 | Oct 5 - Oct 20 |
| Southern Illinois | 6b, 7a | Apr 1 - Apr 15 | Oct 15 - Nov 1 |
Garlic Planting Schedule for Illinois
Northern Illinois (Chicago) (Zones 5a, 5b)
Average last frost: Apr 25 - May 10 · Average first frost: Oct 1 - Oct 15
Central Illinois (Zones 5b, 6a)
Average last frost: Apr 15 - May 1 · Average first frost: Oct 5 - Oct 20
Southern Illinois (Zones 6b, 7a)
Average last frost: Apr 1 - Apr 15 · Average first frost: Oct 15 - Nov 1
Growing Garlic in Illinois
Garlic in Illinois's Climate
Your climate grows both hardneck and softneck garlic well. Plant in October-November, 6 weeks before ground freeze. Hardneck varieties produce scapes in June (harvest and eat them) and bulbs in July. Softneck varieties store longer. Your moderate winter provides enough cold for vernalization without the extreme that can heave poorly mulched cloves.
Soil Considerations for Illinois
Rich prairie soils — some of the most fertile in the country. Heavy clay in many areas. Well-suited for most vegetables. Loose, well-drained soil is especially important for garlic since the edible portion grows underground. If your soil is heavy clay, consider raised beds.
Illinois Climate & Growing Season
Continental climate with four seasons. Hot, humid summers. Cold winters. Good growing season length in central and southern regions. Garlic can handle frost well, which is an advantage in Illinois's climate. You can push planting dates earlier in spring and extend into fall.
Growing season length varies across Illinois: Northern Illinois (Chicago) (5a, 5b) has a last frost around Apr 25 - May 10, while Southern Illinois (6b, 7a) sees frost end around Apr 1 - Apr 15. This difference matters for garlic — adjust your planting dates to match your specific region.
Growing Tips
Plant individual cloves pointy-side up in fall, 4-6 weeks before ground freezes. Mulch heavily. Harvest when lower leaves brown.
Companion Planting
Plant garlic alongside these companions for better growth:
Keep garlic away from:
The Bottom Line
Last reviewed: March 29, 2026