Hi Carol, since you mentioned you prefer smaller roads, you could take Lake Shore Drive through Chicago and Evanston along the lakefront. It's scenic, but you go through the city. If you're looking to avoid city traffic completely, a great alternative to the Chicago Botanic Garden would be the Morton Arboretum. That makes sense if you're bypassing downtown Chicago and staying on less busy suburban roads. If you want to avoid highways from there, most people would take either US-53 or US-83 to go north on local roads that are still fast with fewer stoplights.
Carol thanks John, much appreciate your comments, but we like to stay away from the highways and will probably take one of the smaller roads like route 29, then 69 to 65 towards Chi. But thanks so much.