Experts and BHG readers answer.
Thanks for writing. There's a wealth of really wonderful summer-flowering perennials and shrubs you can plant now (just keep them well watered while they become established).
Because there are too many to list, I'd suggest checking out our online Plant Encyclopedia --- you can do a search for sun/shade plants for your particular Zone that bloom in summer and/or fall.
---Justin, Senior Garden Editor, BHG.com