Ask Mr. Smarty Plants

This looks like a fun project even though you are describing a situation that can be quite elusive for most gardeners (attractive and colorful with blooms throughout the season).

It's not impossible, though, and you will be able to devise your own scheme using our Native Plant Database .  You can do a Combination Search for Illinois and then select the conditions (shade/part shade and wet/dry?) for shrubs, perennials and so on.  You can narrow down the search according to bloom time and color.

For instance, when I selected shade/part shade, moist soil, shrubs and white flowers, blooming in June, a list of 37 plants is generated.  Each plant on the list is linked to a detailed plant information page.

A few that I like from that list are:

Arctostaphylos uva-ursi (kinnikinnick) (this is a ground cover)

Cornus alternifolia (alternateleaf dogwood)

Hydrangea arborescens (wild hydrangea)

When selecting the same conditions but perennials (herbs) that bloom blue in August & September, there are 16 to choose from.

Gentianopsis crinita (greater fringed gentian)

Iris versicolor (harlequin blueflag)

Lobelia siphilitica (great blue lobelia)

And so on ... you can do a number of searches for the various plant types and bloom color/time.  Ultimately, your choices will be limited by the plants you can find in the nurseries in your area (and the fact that you won't really find any yellow flowering plants ... generally, sunny colored flowers like full sun!).  I'm sure you'll quickly get the hang of it and will soon have a lengthy wish list and a great garden plan.

Arctostaphylos uva-ursi

Cornus alternifolia

Hydrangea arborescens

Gentianopsis crinita

Iris versicolor

Lobelia siphilitica