In my urban garden I don't face many of the same pests that other gardeners in the Chicagoland area have to deal with. We have no deer in my neighborhood, the squirrels rarely visit my garden, rabbits and raccoons are rare. If you have trouble keeping flowers because they're always being eaten by some animal I'd suggest planting some spring flowering bulbs that are wildlife resistant in the Chicagoland area.
The Chicago Botanic Garden published a short list on their website recently of spring blooming bulbs they recommend for gardeners dealing with garden pests. You can write down these names and take the list with you as you buy bulbs for your garden this fall.
One thing I'd like to point out is that they are "resistant" to wildlife, there is no guarantee that the odd deer or squirrel won't graze or completely eat these flowers and their foliage. An animal hungry enough will eat just about anything, but they usually stay away from plants like these that don't taste so great when they have other options.
I have a few of these growing in my garden now and have planted many of the others bulbs. One recommendation I'd like to make here is that you are planning on planting small bulbs like, scilla or muscari you buy a lot of them. If you buy one package of these, that usually consist of a handful of bulbs, you'll probably be disappointed come spring when what you planted doesn't look as spectacular as the picture on the package. The pictures are usually taken in established gardens where hundreds or thousands of these bulbs are blooming at once. So, the smaller the bulb the more of them you should plant together to create that visual impact in your garden that caught your eye and made you buy them.