Artists spent up to 15 hours carving each of the jack-o'-lanterns on display for the annual event, Night of 1,000 Jack-o'-Lanterns, according to the garden. Design themes this year range from Optical Illusions to Chicago Classics.
Some of the biggest pumpkins weigh 150 pounds or more.
The model railroad inside the garden is also decked out for Halloween with spooky decorations running along the tracks.
Also new this year is that the garden added an extra night to the event; it opened Wednesday night and runs through Sunday.
For the jack-o'-lantern exhibit, the Botanic Garden reopens nightly from 6 p.m.-10:30 p.m. Attendees can purchase timed tickets to get in.
Entry for non-garden members is $18 for adults and $15 for children ages 3-12. Members get in for $16 for adults at $13 for children. Tickets can be purchased online.