Based on 2,014 research-grade iNaturalist flowering observations in Illinois, Prairie Trillium blooms mainly from April to May, peaking in May. It ranks #3 among wildflowers recorded in the state in our data.
Trillium recurvatum
Prairie Trillium in Illinois by month
Bars show research-grade observations per month. They mix true seasonality with how often people are outdoors, so treat small numbers with caution.
Also in bloom in Illinois in May
Eastern Shooting Star
Virginia bluebells
Large White Trillium
Garlic Mustard
Red Columbine
Atlantic camas
Wild Geranium
Mayapple
Places to look in Illinois
State ParkCahokia
Botanical GardenMorton Arboretum
National ForestShawnee National Forest
Botanical GardenChicago Botanic Garden
Botanical GardenLadd Arboretum
State ParkStarved Rock State Park
FAQ
When does Prairie Trillium bloom in Illinois?
Mainly April–May, with the most records in May.
How common is Prairie Trillium in Illinois?
It ranks #3 by number of iNaturalist flowering observations among wildflowers in Illinois (2,014 records in our sample).